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The compound 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO) is a versatile fluorophore widely used in Förster resonance energy transfer (FRET) spectroscopy studies due to its remarkable sensitivity, enabling precise donor–acceptor distance measurements, even for short peptides. Integrating time-resolved and FRET spectroscopies with molecular dynamics simulations provides a robust approach to unravel the structure and dynamics of biopolymers in a solution. This study investigates the structural behavior of three octapeptide variants: Trp-(Gly-Ser)3-Dbo, Trp-(GlyGly)3-Dbo, and Trp-(SerSer)3-Dbo, where Dbo represents the DBO-containing modified aspartic acid, using molecular dynamics simulations. Glycine- and serine-rich amino acid fragments, common in flexible protein regions, play essential roles in functional properties. Results show excellent agreement between end-to-end distances, orientational factors from simulations, and the available experimental and theoretical data, validating the reliability of the GROMOS force field model. The end-to-end distribution, modeled using three Gaussian distributions, reveals a complex shape, confirmed by cluster analysis highlighting a limited number of significant conformations dominating the peptide landscape. All peptides predominantly adopt a disordered state in the solvent, yet exhibit a compact shape, aligning with the model of disordered polypeptide chains in poor solvents. Conformations show marginal dependence on chain composition, with Ser-only chains exhibiting slightly more elongation. This study enhances our understanding of peptide behavior, providing valuable insights into their structural dynamics in solution. [ABSTRACT FROM AUTHOR]

The regulatory serine protease, complement factor I (FI), in conjunction with one of its cofactors (FH, C4BP, MCP, or CR1), plays an essential role in controlling complement activity through inactivation of C3b and C4b. The functional impact by missense variants in the CFI gene, particularly those with minor allele frequencies of 0.01% to 0.1%, is infrequently studied. As such, these variants are typically classified as variants of uncertain significance (VUS) when they are identified by clinical testing. Herein, we utilized a minigene splicing assay to assess the functional impact of 36 ultra-rare variants of CFI. These variants were selected based on their minor allele frequencies (MAF) and their association with low-normal FI levels. Four variants lead to aberrant splicing-one 5' consensus splice site (NM_000204.5: c.1429G>C, p. Asp477His) and three exonic changes (c.355G>A, p.Gly119Arg; c.472G>A, p.Gly158Arg; and c.950G>A, p.Arg317Gln)- enabling their reclassification to likely pathogenic (LP) or pathogenic (P) based on ACMG guidelines. These findings underscore the value of functional assays, such as the minigene assay, in assessing the clinical relevance of rare variants in CFI. [ABSTRACT FROM AUTHOR]

Serine is a functional amino acid that effectively regulates the physiological functions of an organism. This study investigates the effects of adding exogenous serine to a culture medium to explore a feasible method for the rejuvenation of V. volvacea degenerated strains. The tissue isolation subcultured strains T6, T12, and T19 of V. volvacea were used as test strains, and the commercially cultivated strain V844 (T0) was used as a control. The results revealed that the addition of serine had no significant effect on non-degenerated strains T0 and T6, but could effectively restore the production characteristics of degenerated strains T12 and T19. Serine increased the biological efficiency of T12 and even helped the severely degenerated T19 to regrow its fruiting body. Moreover, exogenous serine up-regulated the expression of some antioxidant enzyme genes, improved antioxidase activity, reduced the accumulation of reactive oxygen species (ROS), lowered malondialdehyde (MDA) content, and restored mitochondrial membrane potential (MMP) and mitochondrial morphology. Meanwhile, serine treatment increased lignocellulase and mycelial energy levels. These findings form a theoretical basis and technical support for the rejuvenation of V. volvacea degenerated strains and other edible fungi. [ABSTRACT FROM AUTHOR]

Frankliniella occidentalis (Pergande) is a typical omnivorous insect that feeds on host plants, pollens and mite eggs, and poses a threat to crops worldwide. The insulin signalling pathway (ISP) is a typical nutrient‐sensitive pathway that participates in the regulation of various functions in insects. Serine/threonine kinases (AKTs) and phosphoinositide‐dependent kinases (PDKs) are key components of the ISP. In this study, the FoAKT and FoPDK genes in F. occidentalis were cloned, and the effects of three foods on their expression were determined. The expression of FoAKT and FoPDK in the thrips fed on kidney bean leaves supplemented with pine pollen or mite eggs was higher than in those primarily fed on leaves alone. Meanwhile, the fecundity of thrips fed on leaves supplemented with pine pollen was highest. In addition, RNA interference‐mediated knockdown of FoAKT and FoPDK decreased vitellogenin (Vg) content and Vg expression in females, shortened ovariole length, delayed egg development and reduced fecundity and offspring hatching rates. Furthermore, the synthesis of juvenile hormone (JH) was reduced, and the contents of glucose, trehalose, glycogen and trehalase were affected. These results suggest that FoAKT and FoPDK regulate the reproduction of F. occidentalis by regulating Vg and JH production as well as carbohydrate metabolism. [ABSTRACT FROM AUTHOR]

The synthesis of a potential northern fragment for the cyclic depsipeptides vioprolide A and vioprolide C is accomplished. The prepared compound is a pentapeptide and displays the non-canonical amino acid dehydrobutyrine (Dhb) at its C-terminal end. The central position is taken by another non-canonical amino acid, (2 S ,4 R)-4-methylazetidine carboxylic acid (Maz). A route to enantiopure N -Boc-protected Maz (N -Boc-Maz) is developed from l -pyroglutamic acid, and this building block is taken into thiopeptide formation at its C-terminal end by successively coupling serine and threonine fragments. The C-terminal threonine is dehydrated to Dhb before attaching a d -Leu-Ala dipeptide to the N-terminal site of Maz. Several intermediates are directly telescoped into the next reaction step. Starting from N -Boc-Maz, the assembly of the pentapeptide is complete in eight steps with an overall yield of 16%. [ABSTRACT FROM AUTHOR]

Objective: To investigate whether visceral adipose tissue‐derived serine protease inhibitor (vaspin) can alleviate the inhibitory effect of high‐glucose (HG) culture on the proliferation and osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) and to preliminarily explore the underlying mechanisms. Background: High glucose produces damage to the regeneration of periodontal tissue of PDLSCs. The expression level of vaspin in periodontal tissue is high in periodontitis patients and effectively reduced after initial therapy of periodontal diseases. However, the effect of vaspin on PDLSCs remains unknown. Materials and Methods: PDLSCs were cultured in media augmented with 5.5 or 25.0 mM concentrations of glucose to elucidate the impact and mechanism of vaspin on PDLSCs under high glucose in vitro. Proliferation was measured by Cell Counting Kit‐8 (CCK8) assay. Osteogenesis of PDLSCs was assessed by alkaline phosphatase (ALP) staining, ALP activity, and Alizarin Red staining. Quantitative real‐time polymerase chain reaction (qRT‐PCR) and western blot (WB) were used to investigate the osteo‐specific markers. Then, the molecular impact of vaspin in the presence/absence of HG on PDLSCs physiology was determined with TGF‐β1/Smad signaling pathway as the main focus. Results: It was revealed that the proliferation and osteogenic differentiation (OD) of PDLSCs under HG was reduced, and by adding vaspin the anti‐osteogenic impact of HG was relieved. Moreover, vaspin enhanced TGF‐β1/Smad signaling pathway activity. Pretreatment with TGF‐β1 inhibitor blocked vaspin‐triggered TGF‐β1/Smad signal activation and minimized the vaspin‐induced protective effect against HG‐inhibited growth and OD. Conclusions: In summary, vaspin observably reduces HG‐mediated inhibition of PDLSCs OD by modulating the TGF‐β1/Smad signaling pathway. Vaspin may be a potential therapeutic for periodontal tissue regeneration in diabetic patients. [ABSTRACT FROM AUTHOR]

Cationic gemini surfactants have emerged as potential gene delivery agents as they can co-assemble with DNA due to a strong electrostatic association. Commonly, DNA complexation is enhanced by the inclusion of a helper lipid (HL), which also plays a key role in transfection efficiency. The formation of lipoplexes, used as non-viral vectors for transfection, through electrostatic and hydrophobic interactions is affected by various physicochemical parameters, such as cationic surfactant:HL molar ratio, (+/−) charge ratio, and the morphological structure of the lipoplexes. Herein, we investigated the DNA complexation ability of mixtures of serine-based gemini surfactants, (nSer)2N5, and monoolein (MO) as a helper lipid. The micelle-forming serine surfactants contain long lipophilic chains (12 to 18 C atoms) and a five CH2 spacer, both linked to the nitrogen atoms of the serine residues by amine linkages. The (nSer)2N5:MO aggregates are non-cytotoxic up to 35–90 µM, depending on surfactant and surfactant/MO mixing ratio, and in general, higher MO content and longer surfactant chain length tend to promote higher cell viability. All systems efficaciously complex DNA, but the (18Ser)2N5:MO one clearly stands as the best-performing one. Incorporating MO into the serine surfactant system affects the morphology and size distribution of the formed mixed aggregates. In the low concentration regime, gemini–MO systems aggregate in the form of vesicles, while at high concentrations the formation of a lamellar liquid crystalline phase is observed. This suggests that lipoplexes might share a similar bilayer-based structure. [ABSTRACT FROM AUTHOR]

Introduction: Neuroinflammation serves as a critical local defense mechanism against secondary brain injury following intracerebral hemorrhage (ICH), and astrocytes play a prominent role in this process. In this study, we investigated astrocytic changes during the inflammatory state after ICH to identify new targets for improving the inflammatory response. Methods: We stimulated mouse astrocytes with lipopolysaccharide (LPS) in vitro and analyzed their transcriptomes via ribonucleic acid sequencing. We created an ICH model in living organisms by injecting autologous blood. Results: RNA sequencing revealed that 2,717 genes were differentially expressed in the LPS group compared to those in the saline group, with notable enrichment of the autophagic pathway. By intersecting the 2,717 differentially expressed genes (DEGs) with autophagy-related genes, we identified 36 autophagyrelated DEGs and seven hub genes. Previous studies and quantitative reverse transcription-polymerase chain reaction results confirmed the increased expression of phosphatidylinositol 3-kinase catalytic subunit type 3 (Pik3c3), AKT serine/threonine kinase 1 (Akt1), and unc-51 like autophagy activating kinase 2 (Ulk2) in astrocytes after ICH. Transcription factors and target miRNAs were identified for the final three DEGs, and 3-methyladenine and leupeptin were identified as potential therapeutic agents for ICH. Conclusion: Our findings suggest that astrocyte autophagy plays a critical role in ICH complexity, and that Pik3c3, Akt1, and Ulk2 may be potential therapeutic targets. [ABSTRACT FROM AUTHOR]

Mucus injury associated with goblet cell (GC) depletion constitutes an early event in inflammatory bowel disease (IBD). Using single-cell sequencing to detect critical events in mucus dysfunction, we discover that the Kazal-type serine protease inhibitor SPINK4 is dynamically regulated in colitic intestine in parallel with disease activities. Under chemically induced colitic conditions, the grim status in Spink4-conditional knockout mice is successfully rescued by recombinant murine SPINK4. Notably, its therapeutic potential is synergistic with existing TNF-α inhibitor infliximab in colitis treatment. Mechanistically, SPINK4 promotes GC differentiation using a Kazal-like motif to modulate EGFR-Wnt/β-catenin and -Hippo pathways. Microbiota-derived diacylated lipoprotein Pam2CSK4 triggers SPINK4 production. We also show that monitoring SPINK4 in circulation is a reliable noninvasive technique to distinguish IBD patients from healthy controls and assess disease activity. Thus, SPINK4 serves as a serologic biomarker of IBD and has therapeutic potential for colitis via intrinsic EGFR activation in intestinal homeostasis. The early stages of inflammatory bowel disease involve mucus injury and depletion of goblet cells. Here, the authors show that SPINK4 could serve as a serological biomarker of IBD and holds therapeutic potential for goblet cell regeneration via intrinsic EGFR activation under colitic conditions [ABSTRACT FROM AUTHOR]

The emergence and spread of antibiotic resistance represent a growing threat to public health. Of particular concern is the appearance of β-lactamases, which are capable to hydrolyze and inactivate the most important class of antibiotics, the β-lactams. Effective β-lactamase inhibitors and mechanistic insights into their action are central in overcoming this type of resistance, and in this context boronate-based β-lactamase inhibitors were just recently approved to treat multidrug-resistant bacteria. Using boric acid as a simplified inhibitor model, time-resolved serial crystallography was employed to obtain mechanistic insights into binding to the active site serine of β-lactamase CTX-M-14, identifying a reaction time frame of 80–100 ms. In a next step, the subsequent 1,2-diol boric ester formation with glycerol in the active site was monitored proceeding in a time frame of 100–150 ms. Furthermore, the displacement of the crucial anion in the active site of the β-lactamase was verified as an essential part of the binding mechanism of substrates and inhibitors. In total, 22 datasets of β-lactamase intermediate complexes with high spatial resolution of 1.40–2.04 Å and high temporal resolution range of 50–10,000 ms were obtained, allowing a detailed analysis of the studied processes. Mechanistic details captured here contribute to the understanding of molecular processes and their time frames in enzymatic reactions. Moreover, we could demonstrate that time-resolved crystallography can serve as an additional tool for identifying and investigating enzymatic reactions. Boronate-based ß-lactamase inhibitors play an important role in treating multidrug-resistant bacteria infection, however, the molecular mechanism of inhibition remains unclear. Here, the authors use time-resolved serial crystallography to investigate the binding process by using boric acid as a model against β-lactamase CTX-M-14, revealing the binding to the active site serine within 80–100 ms, a subsequent 1,2-diol boric ester formation with glycerol within 100–150 ms, as well as the displacement of the sulfate anion in the active site. [ABSTRACT FROM AUTHOR]

Background: Neurodevelopmental disorders (NDDs) can cause debilitating impairments in social cognition and aberrant functional connectivity in large-scale brain networks, leading to social isolation and diminished everyday functioning. To facilitate the treatment of social impairments, animal models of NDDs that link Nmethyl-D-aspartate receptor (NMDAR) hypofunction to social deficits in adulthood have been used. However, understanding the etiology of social impairments in NDDs requires investigating social changes during sensitive windows during development. Methods: We examine social behavior during adolescence using a translational mouse model of NMDAR hypofunction (SR-/-) caused by knocking out serine racemase (SR), the enzyme needed to make D-serine, a key NMDAR coagonist. Species-typical social interactions are maintained through brain-wide neural activation patterns; therefore, we employed whole-brain cFos activity mapping to examine network-level connectivity changes caused by SR deletion. Results: In adolescent SR-/- mice, we observed disinhibited social behavior toward a novel conspecific and rapid social habituation toward familiar social partners. SR-/- mice also spent more time in the open arm of the elevated plus maze which classically points to an anxiolytic behavioral phenotype. These behavioral findings point to a generalized reduction in anxiety-like behavior in both social and non-social contexts in SR-/- mice; importantly, these findings were not associated with diminished working memory. Inter-regional patterns of cFos activation revealed greater connectivity and network density in SR-/- mice compared to controls. Discussion: These results suggest that NMDAR hypofunction - a potential biomarker for NDDs - can lead to generalized behavioral disinhibition in adolescence, potentially arising from disrupted communication between and within salience and default mode networks. [ABSTRACT FROM AUTHOR]

Background and Aim: Bovine viral diarrhea (BVD), a highly pathogenic ribonucleic acid (RNA) virus, causes devastating financial losses and reproductive deaths among dairy cattle in Yogyakarta and globally. This study aimed to identify point mutations within the E2 structural protein of the acquired BVD virus (BVDV) isolates using genetic analysis. Materials and Methods: The study period shows that we performed the research in 2023. We collected 118 serum samples from 2019 to 2023, among which only 10 BVDV positive were used and 108 were negative lacking the BVDV antigen. An anti-Erns monoclonal antibody-coated protein was used in indirect antigen capture enzyme-linked immunosorbent assay (I-ACE) to detect the BVD antigen present in positive BVDV serum specimens. In the initial step of the two-step reverse transcription polymerase chain reaction, the enzyme (superscript III reverse transcriptase) and the primer (random hexamer) were used to convert the RNA of the BVDV into complementary deoxyribonucleic acid (cDNA) during the process of reverse transcription. The final step involved the amplification of the E2 gene of the resultant BVDV cDNA through gene-specific primers (E2_fwd: 5'-TGGTGGCCTTATGAGAC-3' and P7_rev: 5'-CCCATCATCACTATTTCACC-3') and enzyme (platinum taq DNA polymerase high fidelity). For conducting Sanger sequencing, those 3 BVDV-1-positive isolates (about 2.6% of all isolates) were selected as a typical specimen for each site and year between 2019 and 2023 using a proportional computation. Therefore, only two BVDV isolates with complete genomes were chosen to perform their homological and genetic analysis based on the E2 gene by means of Blast and MEGA Version 11 in addition to the Bioedit 7.2.5 program. Results: By applying phylogenetic analysis relying on the E2 gene, a sum of 1011 nucleotides of the BVDV-1 isolates derived from each of the two BVDV-1 Indonesian isolates (n = 2) and its 23 reference BVDV strains were acquired from the National Center for Biotechnology Information (NCBI) database. The findings of the genetic analysis inside the phylogenetic tree revealed that the two BVDV Indonesian isolates were clustered into BVDV-1a subgenotype, while the reference BVDV strains were clustered into the five BVDV subgenotype, BVDV-1a (n = 6), BVDV-1b (n = 3), BVDV-1c (n = 11), BVDV-1m (n = 1), and BVDV-1n (n = 2). The branch exists in phylogenetic tree located before the division of our two BVDV isolates was divided into two branches with the same maximum bootstrap values of 99%, indicating a high degree of confidence, was seen. Next, we observed the branch near our study samples, which displayed the bootstrap value of 100, indicating that our 02 isolates were identical. In both isolates, V11 BVDV1/Indonesia/Yogyakarta/2023 and V16 BVDV1/Indonesia/ Yogyakarta/2023 with GenBank accession numbers PP836388 and PP836389, respectively, conserved D7E residues were mutated as well as cysteine changed/altered into serine (S) was identified at amino acid position 201. Conclusion: We identified two isolates of BVDV belonging to the BVDV-1a subgenotype. Our findings indicate that the conserved D7E residues of isolates V11 BVDV1/Indonesia/Yogyakarta/2023 and V16 BVDV1/Indonesia/Yogyakarta/2023 were altered. The Indonesian BVDV isolates exhibited a cysteine to serine mutation at amino acid position 201, leads to vaccination failure, range of animal's host will increase, and diagnostic kit will not be effective. [ABSTRACT FROM AUTHOR]

Infectious diseases have been jeopardized problem that threaten public health over a long period of time. The growing prevalence of drug‐resistant pathogens and infectious cases have led to a decrease in the number of effective antibiotics, which highlights the urgent need for the development of new antibacterial agents. Serine acetyltransferase (SAT), also known as CysE in certain bacterial species, and O‐acetylserine sulfhydrylase (OASS), also known as CysK in select bacteria, are indispensable enzymes within the cysteine biosynthesis pathway of various pathogenic microorganisms. These enzymes play a crucial role in the survival of these pathogens, making SAT and OASS promising targets for the development of novel anti‐infective agents. In this comprehensive review, we present an introduction to the structure and function of SAT and OASS, along with an overview of existing inhibitors for SAT and OASS as potential antibacterial agents. Our primary focus is on elucidating the inhibitory activities, structure–activity relationships, and mechanisms of action of these inhibitors. Through this exploration, we aim to provide insights into promising strategies and prospects in the development of antibacterial agents that target these essential enzymes. [ABSTRACT FROM AUTHOR]

The amine group (NH2) and the carboxyl group (COOH-) are the fundamental components of amino acids. They regulate several essential physiological functions of organisms and are found in all forms of life, including humans, plants, and microorganisms. Furthermore, they serve as vital energy sources and also act as neurotransmitters. An analysis of the kidneys of Pterocles alchata, an Iraqi Pin-tailed sandgrouse, revealed the presence of 18 specific amino acids. The data indicate that there were no significant differences in the total amounts of amino acids among the three renal lobes. The concentrations in the anterior, middle, and posterior lobes were measured to be 14.154±97.273, 12.437±87.255, and 11.882±88.157 correspondingly, with a significance level of p≤0.05. There were considerable variations in the amounts of amino acids among different areas of the kidney. A glutamine, serine, and asparagine surplus was most pronounced in the kidney lobes. Glutamate proportions were 14.38±226.661 in the back lobe, 22.9±231.929 in the middle lobe, and 27.74±261.852 in the front lobe. The statistical significance of these changes was determined using a significance level of p≤0.05.. Applying a probability threshold of p≤0.01, the serine concentrations in the kidney lobes were measured as 29.59±226.65, 17.74±202.183, and 7.71±199.840 in the anterior, middle, and posterior lobes, respectively. The concentration of the amino acid asparagine (Asn) in the anterior lobe was 12.61±153.952, in the middle lobe it was 7.47±135.278, and in the posterior lobe it was 10.23±128.885. These concentrations were observed at a probability threshold of p≤0.05 [ABSTRACT FROM AUTHOR]

Continuous fusion and fission are critical for mitochondrial health. In this study, we further characterize the role played by dynamin‐related protein 1 (Drp1) in mitochondrial fission. We show that a single amino acid change in Drp1 at position 39 from serine to alanine (S39A) within the GTP‐binding (GTPase) domain results in a fused mitochondrial network in human SH‐SY5Y neuroblastoma cells. Interestingly, the phosphorylation of Ser‐616 and Ser‐637 of Drp1 remains unaffected by the S39A mutation, and mitochondrial bioenergetic profile and cell viability in the S39A mutant were comparable to those observed in the control. This leads us to propose that the serine 39 residue of Drp1 plays a crucial role in mitochondrial distribution through its involvement in the GTPase activity. Furthermore, this amino acid mutation leads to structural anomalies in the mitochondrial network. Taken together, our results contribute to a better understanding of the function of the Drp1 protein. [ABSTRACT FROM AUTHOR]

Background & Objective: Polycystic ovary syndrome is the prevailing endocrine disorder in females and one of the main causes of anovulatory sterility. It is associated with symptoms, disturbs females of reproductive age and affects their quality of life. Cathepsins are proteases that perform a variety of physiological tasks, including activating the complement system, regulating the immune system, and regulating, tissue homeostasis, and ion channel functioning. There are various subtypes, including aspartic, cysteine, and serine cathepsins. Cat S belongs to the family of cysteine cathepsin proteases. A lysosomal protease can encourage the endo-lysosomal pathway's destruction of undesirable or damaged proteins. The present study was conducted with aim to investigate the relationship between cathepsin S and Insulin Resistance in Iraqi women with PCOS. Materials & Methods: An Observational Case-Control Study was performed. The levels of cathepsin S, Insulin, glucose, and insulin resistance were evaluated for 135 blood samples (90 patients and 45 controls). Cathepsin S and Fasting Insulin were estimated by sandwich ELISA method, while glucose was performed using the COBAS INTEGRA 400 plus analyzer. Insulin resistance was calculated by the HOMA-IR formula. All the test procedures were performed at the College of Medicine’s Research Unit /Al-Nahrain University/ Baghdad-Iraq. The study was conducted from December to the end of March of 2023. Results: The levels of cathepsin S, Insulin, HOMA-IR, and glucose were elevated among PCOS patients with a high significant difference (HS) (P<0.0001) between the patient and the control groups. Conclusion: According to the results of this study, Cat S has the potential to be a novel vital component among PCOS parameters. Insulin Resistance continues to rise among PCOS women leading to a necessity for studying its specific mechanism and its genetic origins. [ABSTRACT FROM AUTHOR]

Purpose: Early identification of new residual risk factors for coronary heart disease (CHD) is warranted. In this study, we aim to investigate the association between the serine concentration, an important amino acid in one-carbon metabolism, and CHD in Chinese hospitalized patients. Patients and Methods: This case–control study included 428 case–control pairs comprising patients with CHD with a maximum coronary artery stenosis degree of > 70% and controls with stenosis of < 30%. The individuals were matched by age, sex, and date of coronary angiography at Peking University First Hospital from January 1, 2016, to December 31, 2019. Conditional logistic regression was used to investigate the associations between the serine concentration and CHD. Results: Patients with CHD were aged 63.48 ± 10.38 years, and 43.73% were male. Compared with controls, patients with CHD had a slightly lower serine concentration (13.35 ± 4.20 vs 13.77 ± 4.08 μg/mL), but the difference was not significant. In the multivariable conditional logistic regression analysis, for every 1 μg/mL increase in serine concentration, the odds of CHD decreased by 6% (95% confidence interval [CI] 0.90– 0.99; P = 0.010). Patients with a serine concentration of ≥ 13.41 μg/mL had a lower CHD risk than those with a serine concentration of < 13.41 μg/mL (odds ratio [OR] 0.57, 95% CI 0.39– 0.84; P = 0.004). Subgroup analyses showed that sex interacted with the relationship between serine concentration and CHD (Pinteraction = 0.039), which was more significant in males (OR 0.93, 95% CI 0.87– 0.98; P = 0.013) than in females. Conclusion: This study observed an inverse association between the serine concentration and CHD prevalence in Chinese hospitalized patients, which revealed that serine might play a protective role in CHD. [ABSTRACT FROM AUTHOR]

Background and Aim: Bovine viral diarrhea (BVD), a highly pathogenic ribonucleic acid (RNA) virus, causes devastating financial losses and reproductive deaths among dairy cattle in Yogyakarta and globally. This study aimed to identify point mutations within the E2 structural protein of the acquired BVD virus (BVDV) isolates using genetic analysis. Materials and Methods: The study period shows that we performed the research in 2023. We collected 118 serum samples from 2019 to 2023, among which only 10 BVDV positive were used and 108 were negative lacking the BVDV antigen. An anti-Erns monoclonal antibody-coated protein was used in indirect antigen capture enzyme-linked immunosorbent assay (I-ACE) to detect the BVD antigen present in positive BVDV serum specimens. In the initial step of the two-step reverse transcription polymerase chain reaction, the enzyme (superscript III reverse transcriptase) and the primer (random hexamer) were used to convert the RNA of the BVDV into complementary deoxyribonucleic acid (cDNA) during the process of reverse transcription. The final step involved the amplification of the E2 gene of the resultant BVDV cDNA through gene-specific primers (E2_fwd: 5′-TGGTGGCCTTATGAGAC-3′ and P7_rev: 5′-CCCATCATCACTATTTCACC-3′) and enzyme (platinum taq DNA polymerase high fidelity). For conducting Sanger sequencing, those 3 BVDV-1-positive isolates (about 2.6% of all isolates) were selected as a typical specimen for each site and year between 2019 and 2023 using a proportional computation. Therefore, only two BVDV isolates with complete genomes were chosen to perform their homological and genetic analysis based on the E2 gene by means of Blast and MEGA Version 11 in addition to the Bioedit 7.2.5 program. Results: By applying phylogenetic analysis relying on the E2 gene, a sum of 1011 nucleotides of the BVDV-1 isolates derived from each of the two BVDV-1 Indonesian isolates (n = 2) and its 23 reference BVDV strains were acquired from the National Center for Biotechnology Information (NCBI) database. The findings of the genetic analysis inside the phylogenetic tree revealed that the two BVDV Indonesian isolates were clustered into BVDV-1a subgenotype, while the reference BVDV strains were clustered into the five BVDV subgenotype, BVDV-1a (n = 6), BVDV-1b (n = 3), BVDV-1c (n = 11), BVDV-1m (n = 1), and BVDV-1n (n = 2). The branch exists in phylogenetic tree located before the division of our two BVDV isolates was divided into two branches with the same maximum bootstrap values of 99%, indicating a high degree of confidence, was seen. Next, we observed the branch near our study samples, which displayed the bootstrap value of 100, indicating that our 02 isolates were identical. In both isolates, V11 BVDV1/Indonesia/Yogyakarta/2023 and V16 BVDV1/Indonesia/ Yogyakarta/2023 with GenBank accession numbers PP836388 and PP836389, respectively, conserved D7E residues were mutated as well as cysteine changed/altered into serine (S) was identified at amino acid position 201. Conclusion: We identified two isolates of BVDV belonging to the BVDV-1a subgenotype. Our findings indicate that the conserved D7E residues of isolates V11 BVDV1/Indonesia/Yogyakarta/2023 and V16 BVDV1/Indonesia/Yogyakarta/2023 were altered. The Indonesian BVDV isolates exhibited a cysteine to serine mutation at amino acid position 201, leads to vaccination failure, range of animal’s host will increase, and diagnostic kit will not be effective.

Purpose: Serine is a major source of one‐carbon units needed for the synthesis of nucleotides and the production of intramitochondrial nicotinamide adenine dinucleotide phosphate (NADPH), and it plays an important role in cancer cell proliferation. The aim of this study was to develop a deuterium (2H) MRS imaging method for imaging tumor serine metabolism. Methods: Sequential (2H) spectra and spectroscopic images were used to monitor the metabolism of [2,3,3‐2H3]serine in patient‐derived glioblastoma cells in vitro and in tumors obtained by their orthotopic implantation in mouse brain. Results: [14,14‐2H2] 5,10‐methylene‐tetrahydrofolate, [2H]glycine, [2H]formate, and labeled water were detected in cell suspensions and water labeling in spectroscopic images of tumors. Studies in cells and tumors with variable mitochondrial content and inhibitor studies in cells demonstrated that most of the labeled serine was metabolized in the mitochondria. Water labeling in the cell suspensions was correlated with formate labeling; therefore, water labeling observed in tumors could be used to provide a surrogate measure of flux in the pathway of one‐carbon metabolism in vivo. Conclusion: The method has the potential to be used clinically to select patients for treatment with inhibitors of one‐carbon metabolism and subsequently to detect their early responses to such treatment. [ABSTRACT FROM AUTHOR]

Objective: Livestock droppings cause some environmental problems, but they have the potential to be used as effective biomass resources. The black soldier fly (BSF), Hermetia illucens (Diptera: Stratiomyidae), is suitable for efficiently processing such resources. By using BSF larvae for the disposal of livestock droppings, we can obtain two valuable products: protein resources and organic fertilizer. However, there is insufficient research on the digestive enzymes suitable for processing this waste. Here, we aimed to construct an efficient BSF processing system using livestock droppings, and we explored the digestive enzymes involved in this process. Results: First, we investigated the characteristics of transcripts expressed in the midgut of BSF larvae and found that immune response-related genes were expressed in the midgut. Then, we investigated digestive enzymes and identified a novel serine protease, HiBrachyurin, whose mRNA was highly expressed in the posterior midgut when BSF larvae fed on horse droppings. Despite the low protein content of horse droppings, larvae that fed on horse droppings accumulated more protein than those in the other groups. Therefore, HiBrachyurin may contribute to digestibility in the early stage of protein degradation in BSF larvae fed on horse droppings. [ABSTRACT FROM AUTHOR]

Background: Mammalian display is an appealing technology for therapeutic antibody development. Despite the advantages of mammalian display, such as full-length IgG display with mammalian glycosylation and its inherent ability to select antibodies with good biophysical properties, the restricted library size and large culture volumes remain challenges. Bxb1 serine integrase is commonly used for the stable genomic integration of antibody genes into mammalian cells, but presently lacks the efficiency required for the display of large mammalian display libraries. To increase the Bxb1 integrase-mediated stable integration efficiency, our study investigates factors that potentially affect the nuclear localization of Bxb1 integrase. Methods: In an attempt to enhance Bxb1 serine integrase-mediated integration efficiency, we fused various nuclear localization signals (NLS) to the N- and C-termini of the integrase. Concurrently, we co-expressed multiple proteins associated with nuclear transport to assess their impact on the stable integration efficiency of green fluorescent protein (GFP)-encoding DNA and an antibody display cassette into the genome of Chinese hamster ovary (CHO) cells containing a landing pad for Bxb1 integrase-mediated integration. Results: The nucleoplasmin NLS from Xenopus laevis, when fused to the C-terminus of Bxb1 integrase, demonstrated the highest enhancement in stable integration efficiency among the tested NLS fusions, exhibiting over a 6-fold improvement compared to Bxb1 integrase lacking an NLS fusion. Subsequent additions of extra NLS fusions to the Bxb1 integrase revealed an additional 131% enhancement in stable integration efficiency with the inclusion of two copies of C-terminal nucleoplasmin NLS fusions. Further improvement was achieved by co-expressing the Ran GTPase-activating protein (RanGAP). Finally, to validate the applicability of these findings to more complex proteins, the DNA encoding the membrane-bound clinical antibody abrilumab was stably integrated into the genome of CHO cells using Bxb1 integrase with two copies of C-terminal nucleoplasmin NLS fusions and co-expression of RanGAP. This approach demonstrated over 14-fold increase in integration efficiency compared to Bxb1 integrase lacking an NLS fusion. Conclusions: This study demonstrates that optimizing the NLS sequence fusion for Bxb1 integrase significantly enhances the stable genomic integration efficiency. These findings provide a practical approach for constructing larger libraries in mammalian cells through the stable integration of genes into a genomic landing pad. [ABSTRACT FROM AUTHOR]

SUMMARY Photorespiratory serine hydroxymethyltransferases (SHMTs) are important enzymes of cellular one‐carbon metabolism. In this study, we investigated the potential role of SHMT6 in Arabidopsis thaliana. We found that SHMT6 is localized in the nucleus and expressed in different tissues during development. Interestingly SHMT6 is inducible in response to avirulent, virulent Pseudomonas syringae and to Fusarium oxysporum infection. Overexpression of SHMT6 leads to larger flowers, siliques, seeds, roots, and consequently an enhanced overall biomass. This enhanced growth was accompanied by increased stomatal conductance and photosynthetic capacity as well as ATP, protein, and chlorophyll levels. By contrast, a shmt6 knockout mutant displayed reduced growth. When challenged with Pseudomonas syringae pv tomato (Pst) DC3000 expressing AvrRpm1, SHMT6 overexpression lines displayed a clear hypersensitive response which was characterized by enhanced electrolyte leakage and reduced bacterial growth. In response to virulent Pst DC3000, the shmt6 mutant developed severe disease symptoms and becomes very susceptible, whereas SHMT6 overexpression lines showed enhanced resistance with increased expression of defense pathway associated genes. In response to Fusarium oxysporum, overexpression lines showed a reduction in symptoms. Moreover, SHMT6 overexpression lead to enhanced production of ethylene and lignin, which are important components of the defense response. Collectively, our data revealed that SHMT6 plays an important role in development and defense against pathogens. [ABSTRACT FROM AUTHOR]

The serine carboxypeptidase-like (SCPL) gene family plays a crucial role in the regulation of plant growth, development, and stress response through activities such as acyltransferases in plant secondary metabolism pathways. Although SCPL genes have been identified in various plant species, their specific functions and characteristics in soybean (Glycine max) have not yet been studied. We identified and characterized 73 SCPL genes, grouped into three subgroups based on gene structure and phylogenetic relationships. These genes are distributed unevenly across 20 soybean chromosomes and show varied codon usage patterns influenced by both mutation and selection pressures. Gene ontology (GO) enrichment suggests these genes are involved in plant cell wall regulation and stress responses. Expression analysis in various tissues and under stress conditions, including the presence of numerous stress-related cis-acting elements, indicated that these genes have varied expression patterns. This suggests that they play specialized roles such as modulating plant defense mechanisms against nematode infections, enhancing tolerance to drought and high salinity, and responding to cold stress, thereby helping soybean adapt to environmental stresses. Moreover, the expression of specific GmSCPLs was significantly affected following exposure to nematode infection, drought, high salt (NaCl), and cold stresses. Our findings underscore the potential of SCPL genes in enhancing stress resistance in soybean, providing a valuable resource for future genetic improvement and breeding strategies. [ABSTRACT FROM AUTHOR]

Porphyromonas gingivalis produces five classes of serine/glycine lipids that are recovered in lipid extracts from periodontitis‐afflicted teeth and diseased gingival tissues, particularly at sites of periodontitis. Because these lipids are recovered in diseased gingival tissues, the purpose of the present study was to evaluate the capacity of cultured human gingival fibroblasts (HGF), keratinocytes, and macrophages to hydrolyze these lipids. We hypothesize that one or more of these cell types will hydrolyze the serine/glycine lipids. The primary aim was to treat these cell types for increasing time in culture with individual highly enriched serine/glycine lipid preparations. At specified times, cells and culture media samples were harvested and extracted for hydrolysis products. The serine/glycine lipids and hydrolysis products were quantified using liquid chromatography–mass spectrometry (LC–MS) and free fatty acids were quantified using gas chromatograph–mass spectrometer. LC–MS analysis used two different mass spectrometric methods. This study revealed that treatment of HGF or macrophage (THP1) cells with lipid (L) 654 resulted in breakdown to L342 and subsequent release into culture medium. However, L654 was converted only to L567 in gingival keratinocytes. By contrast, L1256 was converted to L654 by fibroblasts and macrophages but no further hydrolysis or release into medium was observed. Gingival keratinocytes showed no hydrolysis of L1256 to smaller lipid products but because L1256 was not recovered in these cells, it is not clear what hydrolysis products are produced from L1256. Although primary cultures of gingival fibroblasts and macrophages are capable of hydrolyzing specific serine/glycine lipids, prior analysis of lipid extracts from diseased gingival tissues revealed significantly elevated levels of L1256 in diseased tissues. These results suggest that the hydrolysis of bacterial lipids in gingival tissues may reduce the levels of specific lipids, but the hydrolysis of L1256 is not sufficiently rapid to prevent significant accumulation at periodontal disease sites. [ABSTRACT FROM AUTHOR]

l -cysteine, a primary building block of mycothiol, plays an essential role in the defense mechanism of Mycobacterium tuberculosis (Mtb). However, it is unclear how Mtb regulates cysteine biosynthesis as no study has reported the cysteine regulatory complex (CRC) in Mtb. Serine acetyltransferase (SAT) and cysteine synthase (CS) interact to form CRC. Although Mt CS has been characterized well, minimal information is available on Mt SAT, which synthesizes, O-acetylserine (OAS), the precursor of cysteine. This study fills the gap and provides experimental evidence for the presence of Mt CRC and a non-canonical multi-oligomeric Mt SAT. We employed multiple analytical methods to characterize the oligomeric and kinetic properties of Mt SAT and Mt CRC. Results show that Mt SAT, lacking >75 N-terminal amino acids exists in three different assembly states; trimer, hexamer, and dodecamer, compared to the single hexameric state of SAT of other bacteria. While hexamers display the highest catalytic turnover, the trimer is the least active. The predominance of trimers at low physiologically relevant concentrations suggests that Mt SAT displays the lowest catalytic potential known. Further, the catalytic potential of Mt SAT is also significantly reduced in CRC state, in contrast to enhanced activity of SAT in CRC of other organisms. Our study provides insights into multi-oligomeric Mt SAT with reduced catalytic potential and demonstrates that both Mt SAT and Mt CS of Mycobacterium interact to form CRC, although with altered catalytic properties. We discuss our results in light of the altered biochemistry of the last step of canonical sulfate-dependent cysteine biosynthesis of Mycobacterium. [Display omitted] • Serine acetyltransferase from Mycobacterium tuberculosis (Mt SAT) lacks four N-terminal helices. • Mt SAT exists in three states, with the trimer demonstrating the least catalytic efficiency. • Only hexamers can form cysteine regulatory complex (CRC) with cysteine synthase, not trimers. • Together, results indicate that compromised catalytic efficiency of Mt SAT may be an evolutionary adaptation. [ABSTRACT FROM AUTHOR]

Summary: Fruit firmness is an important trait in sweet cherry breeding because it directly positively influences fruit transportability, storage and shelf life. However, the underlying genes responsible and the molecular mechanisms that control fruit firmness remain unknown. In this study, we identified a candidate gene, PavSCPL, encoding a serine carboxypeptidase‐like protein with natural allelic variation, that controls fruit firmness in sweet cherry using map‐based cloning and functionally characterized PavSCPL during sweet cherry fruit softening. Genetic analysis revealed that fruit firmness in the 'Rainier' × 'Summit' F1 population was controlled by a single dominant gene. Bulked segregant analysis combined with fine mapping narrowed the candidate gene to a 473‐kb region (7418778–7 891 914 bp) on chromosome 6 which included 72 genes. The candidate gene PavSCPL, and a null allele harbouring a 5244‐bp insertion in the second exon that completely inactivated PavSCPL expression and resulted in the extra‐hard‐flesh phenotype, were identified by RNA‐sequencing analysis and gene cloning. Quantitative RT‐PCR analysis revealed that the PavSCPL expression level was increased with fruit softening. Virus‐induced gene silencing of PavSCPL enhanced fruit firmness and suppressed the activities of certain pectin‐degrading enzymes in the fruit. In addition, we developed functional molecular markers for PavSCPL and the Pavscpl5.2‐k allele that co‐segregated with the fruit firmness trait. Overall, this research identified a crucial functional gene for fruit firmness. The results provide insights into the genetic control and molecular mechanism of the fruit firmness trait and present useful molecular markers for molecular‐assisted breeding for fruit firmness in sweet cherry. [ABSTRACT FROM AUTHOR]

Atherosclerosis is the primary trigger for severe pathologies. The atherosclerotic inflammatory process is well known after low-density lipoprotein (LDL) adhesion in blood vessel walls, however, limited information exists regarding LDL penetration into subendothelial layers. Here, we propose for the first time, to the best of our knowledge, the pathway for the initial trajectory of the lipid molecules internalization into the arterial endothelial tissue. The investigation shows a computational model analyzing molecules involved in the atherosclerotic process, specifically LDL and molecules of the vascular endothelium. The theoretical model was experimentally tested using carrageenan to simulate the anionic counterparts of vascular tissue and amino acids from apolipoprotein B-100. The molecular interactions were analyzed by conductimetric titration, FTIR, and rheology. The computational model identified potential amino acids involved in the process, and the experimental results demonstrated the interaction between lysine and polymer, as the mechanism of adhesion, confirming the model. [ABSTRACT FROM AUTHOR]

Serine peptidases (SPs) of the chymotrypsin S1A subfamily are an extensive group of enzymes found in all animal organisms, including insects. Here, we provide analysis of SPs in the yellow mealworm Tenebrio molitor transcriptomes and genomes datasets and profile their expression patterns at various stages of ontogeny. A total of 269 SPs were identified, including 137 with conserved catalytic triad residues, while 125 others lacking conservation were proposed as non-active serine peptidase homologs (SPHs). Seven deduced sequences exhibit a complex domain organization with two or three peptidase units (domains), predicted both as active or non-active. The largest group of 84 SPs and 102 SPHs had no regulatory domains in the propeptide, and the majority of them were expressed only in the feeding life stages, larvae and adults, presumably playing an important role in digestion. The remaining 53 SPs and 23 SPHs had different regulatory domains, showed constitutive or upregulated expression at eggs or/and pupae stages, participating in regulation of various physiological processes. The majority of polypeptidases were mainly expressed at the pupal and adult stages. The data obtained expand our knowledge on SPs/SPHs and provide the basis for further studies of the functions of proteins from the S1A subfamily in T. molitor. [ABSTRACT FROM AUTHOR]

Brassinosteroids (BRs) are widely used as plant growth regulators in modern agriculture. Understanding how BRs regulate nutrient signaling is crucial for reducing fertilizer usage. Here we elucidate that the central BR signaling inhibitor GSK3/SHAGGY-LIKE KINASE2 (GSK2) interacts directly with and phosphorylates PHOSPHATE STARVATION RESPONSE2 (OsPHR2), the key regulator of phosphate (Pi) signaling, to suppress its transcription factor activity in rice (Oryza sativa). We identify a critical phosphorylation site at serine residue S269 of OsPHR2 and demonstrate that phosphorylation by GSK2 or phosphor-mimic mutation of S269 substantially impairs the DNA-binding activity of OsPHR2, and thus diminishes expression of OsPHR2-induced genes and reduces Pi levels. Like BRs, Pi starvation noticeably induces GSK2 instability. We further show that this site-specific phosphorylation event is conserved in Arabidopsis (Arabidopsis thaliana), but varies among the PHR-family members, being present only in most land plants. These results unveil a distinctive post-transcriptional regulatory mechanism in Pi signaling by which BRs promote Pi acquisition, with a potential contribution to the environmental adaptability of plants during their evolution. Brassinosteroids modulate phosphate homeostasis by phosphorylating a serine residue of OsPHR2 through GSK2, thereby attenuating its DNA-binding activity. [ABSTRACT FROM AUTHOR]

Cancer testis antigens (CTAs) are a collection of proteins whose expression is normally restricted to the gamete but abnormally activated in a wide variety of tumors. The CTA, Testis-specific serine kinase 6 (TSSK6), is essential for male fertility in mice. The functional relevance of TSSK6 to cancer, if any, has not previously been investigated. Here we find that TSSK6 is frequently anomalously expressed in colorectal cancer and patients with elevated TSSK6 expression have reduced relapse-free survival. Depletion of TSSK6 from colorectal cancer cells attenuates anchorage-independent growth, invasion, and growth in vivo. Conversely, overexpression of TSSK6 enhances anchorage independence and invasion in vitro as well as in vivo tumor growth. Notably, ectopic expression of TSSK6 in semi-transformed human colonic epithelial cells is sufficient to confer anchorage independence and enhance invasion. In somatic cells, TSSK6 co-localizes with and enhances the formation of paxillin and tensin-positive foci at the cell periphery, suggesting a function in focal adhesion formation. Importantly, TSSK6 kinase activity is essential to induce these tumorigenic behaviors. Our findings establish that TSSK6 exhibits oncogenic activity when abnormally expressed in colorectal cancer cells. Thus, TSSK6 is a previously unrecognized intervention target for therapy, which could exhibit an exceptionally broad therapeutic window. [ABSTRACT FROM AUTHOR]

The obligate intracellular bacterium, Chlamydia trachomatis, has evolved to depend on its human host for many metabolites, including most amino acids and three of the four nucleotides. Given this, it is not surprising that depletion of a single amino acid in the host cell growth medium blocks chlamydial replication. Paradoxically, supra-normal levels of some amino acids also block productive replication of Chlamydia. Here, we have determined how elevated serine levels, generated by exogenous supplementation, impede chlamydial inclusion development and reduce the generation of infectious progeny. Our findings reveal that human serine racemase, which is broadly expressed in multiple tissues, potentiates the anti-chlamydial effect of elevated serine concentrations. In addition to reversibly converting l-serine to d-serine, serine racemase also deaminates serine via β-elimination. We have determined that d-serine does not directly impact Chlamydia; rather, ammonia generated by serine deamination limits the productive chlamydial replication. Our findings imply that ammonia produced within host cells can traverse the chlamydial inclusion membrane. Further, this property of serine deaminase can be exploited to sensitize Chlamydia to concentrations of doxycycline that are otherwise not bactericidal. Because exogenously elevated levels of serine can be tolerated over extended periods, the broad expression pattern of serine racemase indicates it to be a host enzyme whose activity can be directed against multiple intracellular bacterial pathogens. From a therapeutic perspective, demonstrating host metabolism can be skewed to generate an anti-bacterial metabolite that synergizes with antibiotics, we believe our results provide a new approach to target intracellular pathogens. [ABSTRACT FROM AUTHOR]

A new potential energy surface for forming glycine in the gas phase, starting from association of aminoacetonitrile (NH2CH2CN) with OH followed by subsequent hydrolysis, was determined using CBS‐QB3 calculation. The overall activation energy was 90 kJ mol−1 or 0 without or with catalytic H2O, respectively. Alanine or serine was formed from 2‐aminopropionitrile (CH3CH(NH2)CN) or 2‐amino‐3‐hydrxypropionitrile (HOCH2CH(NH2)CN) instead of aminoacetonitrile with the overall activation energies of 89 or 49 kJ mol−1, respectively. When an additional H2O was involved in each reaction as a catalyst, barrierless reaction pathways were obtained. These results suggest that it is possible for investigated reactions to occur in interstellar ices along the proposed pathways, taking kinetic aspects into account. [ABSTRACT FROM AUTHOR]

Men or mice with homozygous serine/threonine kinase 33 (STK33) mutations are sterile owing to defective sperm morphology and motility. To chemically evaluate STK33 for male contraception with STK33-specific inhibitors, we screened our multibillion-compound collection of DNA-encoded chemical libraries, uncovered potent STK33-specific inhibitors, determined the STK33 kinase domain structure bound with a truncated hit CDD-2211, and generated an optimized hit CDD-2807 that demonstrates nanomolar cellular potency (half-maximal inhibitory concentration = 9.2 nanomolar) and favorable metabolic stability. In mice, CDD-2807 exhibited no toxicity, efficiently crossed the blood-testis barrier, did not accumulate in brain, and induced a reversible contraceptive effect that phenocopied genetic STK33 perturbations without altering testis size. Thus, STK33 is a chemically validated, nonhormonal contraceptive target, and CDD-2807 is an effective tool compound. [ABSTRACT FROM AUTHOR]

Aims Following myocardial infarction (MI), the heart repairs itself via a fibrotic repair response. The degree of fibrosis is determined by the balance between deposition of extracellular matrix (ECM) by activated fibroblasts and breakdown of nascent scar tissue by proteases that are secreted predominantly by inflammatory cells. Excessive proteolytic activity and matrix turnover has been observed in human heart failure, and protease inhibitors in the injured heart regulate matrix breakdown. Serine protease inhibitors (Serpins) represent the largest and the most functionally diverse family of evolutionary conserved protease inhibitors, and levels of the specific Serpin, SerpinA3, have been strongly associated with clinical outcomes in human MI as well as non-ischaemic cardiomyopathies. Yet, the role of Serpins in regulating cardiac remodelling is poorly understood. The aim of this study was to understand the role of Serpins in regulating scar formation after MI. Methods and results Using a SerpinA3n conditional knockout mice model, we observed the robust expression of Serpins in the infarcted murine heart and demonstrate that genetic deletion of SerpinA3n (mouse homologue of SerpinA3) leads to increased activity of substrate proteases, poorly compacted matrix, and significantly worse post-infarct cardiac function. Single-cell transcriptomics complemented with histology in SerpinA3n-deficient animals demonstrated increased inflammation, adverse myocyte hypertrophy, and expression of pro-hypertrophic genes. Proteomic analysis of scar tissue demonstrated decreased cross-linking of ECM peptides consistent with increased proteolysis in SerpinA3n-deficient animals. Conclusion Our study demonstrates a hitherto unappreciated causal role of Serpins in regulating matrix function and post-infarct cardiac remodelling. [ABSTRACT FROM AUTHOR]

Epithelial cells function as the primary line of defense against invading pathogens. However, bacterial pathogens possess the ability to compromise this barrier and facilitate the transmigration of bacteria. Nonetheless, the specific molecular mechanism employed by Mycobacterium tuberculosis (M.tb) in this process is not fully understood. Here, we investigated the role of Rv2569c in M.tb translocation by assessing its ability to cleave E-cadherin, a crucial component of cell-cell adhesion junctions that are disrupted during bacterial invasion. By utilizing recombinant Rv2569c expressed in Escherichia coli and subsequently purified through affinity chromatography, we demonstrated that Rv2569c exhibited cell wall–associated serine protease activity. Furthermore, Rv2569c was capable of degrading a range of protein substrates, including casein, fibrinogen, fibronectin, and E-cadherin. We also determined that the optimal conditions for the protease activity of Rv2569c occurred at a temperature of 37°C and a pH of 9.0, in the presence of MgCl2. To investigate the function of Rv2569c in M.tb, a deletion mutant of Rv2569c and its complemented strains were generated and used to infect A549 cells and mice. The results of the A549-cell infection experiments revealed that Rv2569c had the ability to cleave E-cadherin and facilitate the transmigration of M.tb through polarized A549 epithelial cell layers. Furthermore, in vivo infection assays demonstrated that Rv2569c could disrupt E-cadherin, enhance the colonization of M.tb, and induce pathological damage in the lungs of C57BL/6 mice. Collectively, these results strongly suggest that M.tb employs the serine protease Rv2569c to disrupt epithelial defenses and facilitate its systemic dissemination by crossing the epithelial barrier. Author summary: Mycobacterium tuberculosis (M.tb) causes tuberculosis (TB), a highly contagious respiratory disease and a leading cause of death worldwide. Following the inhalation of aerosol particles, the bacteria often establish a persistent infection within the lungs, leading to the development of the characteristic pulmonary TB syndrome. Additionally, M.tb can breach alveolar barrier, thereby initiating extrapulmonary TB. The pathogenesis of M.tb heavily relies on systemic dissemination, although the precise underlying mechanism remains incompletely elucidated. The alveolar epithelial barrier, composed of tight junctions and adherens junctions, plays a crucial role in safeguarding against invading pathogens. In this study, we present groundbreaking discoveries pertaining to the extracellular serine protease Rv2569c of M.tb, which facilitates bacterial transmigration through the cleavage of E-cadherin. Furthermore, we ascertain that Rv2569c elicits profound pathological harm and enhances M.tb colonization within murine pulmonary tissues. These findings contribute to a deeper comprehension of the pathogenic mechanisms employed by M.tb and hold potential for informing future strategies aimed at controlling TB infections. [ABSTRACT FROM AUTHOR]

Reprogramming of the serine synthesis pathway (SSP) is intricately linked to the progression of epithelial ovarian cancer (EOC). CBR-5884, a selective small-molecule inhibitor targeting phosphoglycerate dehydrogenase (PHGDH), effectively impedes the de novo synthesis of serine within cancer cells. This study aimed to evaluate the inhibitory effect of CBR-5884 on EOC cells and delineate its specific mechanism, thereby proposing a novel therapeutic approach for treating EOC. The suppression of serine biosynthesis after CBR-5884 treatment was evaluated using RNA sequencing and a serine assay kit, and the results showed that CBR-5884 effectively downregulated serine biosynthesis in EOC cells, particularly those expressing high levels of PHGDH. In vitro studies revealed that CBR-5884 demonstrated significant antitumor effects and suppressed migration and invasion of EOC cells through down-regulation of the integrin subunit beta 4 (ITGB4)/extracellular signal-regulated kinase (ERK)/epithelial–mesenchymal transition signal axis. Additionally, CBR-5884 mitigated the stemness of EOC cells and heightened their sensitivity to chemotherapy. Moreover, in vivo studies revealed that CBR-5884 significantly delayed tumor growth, with histological analysis indicating the safety profile of CBR-5884. Finally, the patient-derived organoid (PDO) models were utilized to explore the preclinical efficacy of CBR-5884 against EOC cells, and the results unveiled that CBR-5884 impeded proliferation and downregulated the expression of ITGB4 in EOC PDO models. Our findings supports the anticancer properties of CBR-5884 in EOC cells exhibiting high PHGDH expression, manifesting through the suppression of proliferation, migration, and invasion, while enhancing chemotherapy sensitivity, suggesting that CBR-5884 holds promise as an efficacious strategy for the treatment of EOC. [ABSTRACT FROM AUTHOR]

Chronic myeloid leukemia (CML) is a disease caused by the malignant proliferation of hematopoietic stem cells in the bone marrow. Although tyrosine kinase inhibitors (TKIs) have made significant progress in the treatment of chronic myeloid leukemia, the issue of drug resistance remains unresolved. Therefore, finding new therapeutic drugs and targets is crucial. Studies have shown that miRNAs are closely associated with various tumors, including chronic myeloid leukemia, and oleanolic acid (OA) has a good inhibitory effect on leukemia cells. Through transcriptome sequencing, it was found that oleanolic acid can significantly upregulate the level of serine/threonine protein kinase 4 (STK4), and miR1a-5p is the target miRNA of STK4. Therefore, this article aims to investigate whether oleanolic acid can affect the malignant progression of K562 cells through miR-18a-5p/STK4. The differentially expressed genes in K562 cells were enriched in apoptosis related pathways after treatment with oleanolic acid. The EdU experiment and CCK-8 experiment results showed that oleanolic acid reduced the proliferation ability of K562 cells (P<0.05). qRT-PCR, immunofluorescence, and Western blot results showed that after treatment with oleanolic acid, the expression of STK4 protein was significantly upregulated (P<0.05) and miR-18a-5p was downregulated in K562 cells (P<0.05) . Transfection of miR-18a-5p mimics into cells significantly inhibited the expression of STK4 (P<0.05); Transfection with miR-18a-5p inhibitor significantly increased the expression of STK4 (P<0.05). The results of reactive oxygen species (ROS) detection and mitochondrial membrane potential detection showed that oleanolic acid can promote the increase of ROS in K562 cells and reduce mitochondrial membrane potential. After overexpression of STK4, the mitochondrial membrane potential of the cells decreased compared to the Vector group; Knocking down STK4 can reverse the decrease in mitochondrial membrane potential caused by the oleanolic acid group. Flow cytometry analysis showed that oleanolic acid can significantly promote the occurrence of cell apoptosis, while the apoptosis rate significantly decreased after transfection with miR-18a-5p mimics (P<0.05); Overexpression of STK4 can promote the transformation of cells from early apoptosis to late apoptosis, while simultaneous transfection of miR-18a-5p mimics can inhibit this phenomenon. Our research results confirm that oleanolic acid can promote apoptosis of K562 cells by maintaining low expression of miR-18a-5p and high expression of STK4. [ABSTRACT FROM AUTHOR]

Single nucleotide polymorphisms (SNPs) account for significant genomic variability in microbes, including the highly diverse gastric pathogen Helicobacter pylori. However, data on the effects of specific SNPs in pathogen-host interactions are scarce. Recent functional studies unravelled how a serine/leucine polymorphism in serine protease HtrA affects the formation of proteolytically active trimers and modulates cleavage of host cell-to-cell junction proteins during infection. A similar serine/leucine mutation in the carbohydrate binding domain of the adhesin BabA controls binding of ABO blood group antigens, enabling binding of either only the short Lewis b/H antigens of blood group O or also the larger antigens of blood groups A and B. Here we summarize the functional importance of these two remarkable bacterial SNPs and their effect on the outcome of pathogen-host interactions. [ABSTRACT FROM AUTHOR]

FAM111A gene mutations cause Kenney–Caffey syndrome (KCS) and Osteocraniostenosis (OCS), conditions characterized by short stature, low serum ionized calcium (Ca2+), low parathyroid hormone (PTH), and bony abnormalities. The molecular mechanism mediating this phenotype is unknown. The c‐terminal domain of FAM111A harbors all the known disease‐causing variations and encodes a domain with high homology to serine proteases. However, whether this serine protease domain contributes to the maintenance of Ca2+ homeostasis is not known. We hypothesized the disruption of the serine protease domain of FAM111A would disrupt Ca2+ homeostasis. To test this hypothesis, we generated with CRISPR/Cas9, mice with a frameshift insertion (c.1450insA) or large deletion (c.1253‐1464del) mutation in the Fam111a serine protease domain. Serum‐ionized Ca2+ and PTH levels were not significantly different between wild type, heterozygous, or homozygous Fam111a mutant mice. Additionally, there were no significant differences in fecal or urine Ca2+ excretion, intestinal Ca2+ absorption or overall Ca2+ balance. Only female homozygous (c.1450insA), but not heterozygous mice displayed differences in bone microarchitecture and mineral density compared to wild‐type animals. We conclude that frameshift mutations that disrupt the c‐terminal serine protease domain do not induce a KCS or OCS phenotype in mice nor alter Ca2+ homeostasis. [ABSTRACT FROM AUTHOR]

GRIN -related disorders are rare developmental encephalopathies with variable manifestations and limited therapeutic options. Here, we present the first non-randomized, open-label, single-arm trial (NCT04646447) designed to evaluate the tolerability and efficacy of L-serine in children with GRIN genetic variants leading to loss-of-function. In this phase 2A trial, patients aged 2–18 years with GRIN loss-of-function pathogenic variants received L-serine for 52 weeks. Primary end points included safety and efficacy by measuring changes in the Vineland Adaptive Behavior Scales, Bayley Scales, age-appropriate Wechsler Scales, Gross Motor Function-88, Sleep Disturbance Scale for Children, Pediatric Quality of Life Inventory, Child Behavior Checklist and the Caregiver-Teacher Report Form following 12 months of treatment. Secondary outcomes included seizure frequency and intensity reduction and EEG improvement. Assessments were performed 3 months and 1 day before starting treatment and 1, 3, 6 and 12 months after beginning the supplement. Twenty-four participants were enrolled (13 males/11 females, mean age 9.8 years, SD 4.8), 23 of whom completed the study. Patients had GRIN2B , GRIN1 and GRIN2A variants (12, 6 and 5 cases, respectively). Their clinical phenotypes showed 91% had intellectual disability (61% severe), 83% had behavioural problems, 78% had movement disorders and 58% had epilepsy. Based on the Vineland Adaptive Behavior Composite standard scores, nine children were classified as mildly impaired (cut-off score > 55), whereas 14 were assigned to the clinically severe group. An improvement was detected in the Daily Living Skills domain (P = 0035) from the Vineland Scales within the mild group. Expressive (P = 0.005), Personal (P = 0.003), Community (P = 0.009), Interpersonal (P = 0.005) and Fine Motor (P = 0.031) subdomains improved for the whole cohort, although improvement was mostly found in the mild group. The Growth Scale Values in the Cognitive subdomain of the Bayley-III Scale showed a significant improvement in the severe group (P = 0.016), with a mean increase of 21.6 points. L-serine treatment was associated with significant improvement in the median Gross Motor Function-88 total score (P = 0.002) and the mean Pediatric Quality of Life total score (P = 0.00068), regardless of severity. L-serine normalized the EEG pattern in five children and the frequency of seizures in one clinically affected child. One patient discontinued treatment due to irritability and insomnia. The trial provides evidence that L-serine is a safe treatment for children with GRIN loss-of-function variants, having the potential to improve adaptive behaviour, motor function and quality of life, with a better response to the treatment in mild phenotypes. [ABSTRACT FROM AUTHOR]

Campylobacter jejuni is the leading cause of foodborne human gastroenteritis in the developed world. Infections are largely acquired from poultry produced for human consumption and poor food handling is thus a major risk factor. Chicken exudate (CE) is a liquid produced from defrosted commercial chicken products that facilitates C. jejuni growth. We examined the response of C. jejuni to growth in CE using a multi-omics approach. Changes in the C. jejuni proteome were assessed by label-based liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). We quantified 1328 and 1304 proteins, respectively, in experiments comparing 5% CE in Mueller–Hinton (MH) medium and 100% CE with MH-only controls. These proteins represent 81.8% and 80.3% of the predicted C. jejuni NCTC11168 proteome. Growth in CE induced profound remodelling of the proteome. These changes were typically conserved between 5% and 100% CE, with a greater magnitude of change observed in 100% CE. We confirmed that CE induced C. jejuni biofilm formation, as well as increasing motility and resistance against oxidative stress, consistent with changes to proteins representing those functions. Assessment of the C. jejuni metabolome showed CE also led to increased intracellular abundances of serine, proline, and lactate that were correlated with the elevated abundances of their respective transporters. Analysis of carbon source uptake showed prolonged culture supernatant retention of proline and succinate in CE-supplemented medium. Metabolomics data provided preliminary evidence for the uptake of chicken-meat-associated dipeptides. C. jejuni exposed to CE showed increased resistance to several antibiotics, including polymyxin B, consistent with changes to tripartite efflux system proteins and those involved in the synthesis of lipid A. The C. jejuni CE proteome was also characterised by very large increases in proteins associated with iron acquisition, while a decrease in proteins containing iron–sulphur clusters was also observed. Our data suggest CE is both oxygen- and iron-limiting and provide evidence of factors required for phenotypic remodelling to enable C. jejuni survival on poultry products. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is a heterogeneous hematological malignancy characterized by disrupted blood cell production and function. Recent investigations have highlighted the potential of targeting glutamine metabolism as a promising therapeutic approach for AML. Asparaginases, enzymes that deplete circulating glutamine and asparagine, are approved for the treatment of acute lymphoblastic leukemia, but are also under investigation in AML, with promising results. We previously reported an elevation in plasma serine levels following treatment with Erwinia-derived asparaginase (also called crisantaspase). This led us to hypothesize that AML cells initiate the de novo serine biosynthesis pathway in response to crisantaspase treatment and that inhibiting this pathway in combination with crisantaspase would enhance AML cell death. Here we report that in AML cell lines, treatment with the clinically available crisantaspase, Rylaze, upregulates the serine biosynthesis enzymes phosphoglycerate dehydrogenase (PHGDH) and phosphoserine aminotransferase (PSAT1) through activation of the Amino Acid Response (AAR) pathway, a cellular stress response mechanism that regulates amino acid metabolism and protein synthesis under conditions of nutrient limitation. Inhibition of serine biosynthesis through CRISPR-Cas9-mediated knockout of PHGDH resulted in a ~250-fold reduction in the half-maximal inhibitory concentration (IC50) for Rylaze, indicating heightened sensitivity to crisantaspase therapy. Treatment of AML cells with a combination of Rylaze and a small molecule inhibitor of PHGDH (BI4916) revealed synergistic antiproliferative effects in both cell lines and primary AML patient samples. Rylaze-BI4916 treatment in AML cell lines led to the inhibition of cap-dependent mRNA translation and protein synthesis, as well as a marked decrease in intracellular glutathione levels, a critical cellular antioxidant. Collectively, our results highlight the clinical potential of targeting serine biosynthesis in combination with crisantaspase as a novel therapeutic strategy for AML. [ABSTRACT FROM AUTHOR]

Serine phosphorylations on insulin receptor substrate 1 (IRS-1) by diverse kinases aoccur widely during obesity-, stress-, and inflammation-induced conditions in models of insulin resistance and type 2 diabetes. In this study, we define a region within the human IRS-1, which is directly C-terminal to the PTB domain encompassing numerous serine phosphorylation sites including Ser307 (mouse Ser302) and Ser312 (mouse 307) creating a phosphorylation insulin resistance (PIR) domain. We demonstrate that the IRS-1 PTB-PIR with its unphosphorylated serine residues interacts with the insulin receptor (IR) but loses the IR-binding when they are phosphorylated. Surface plasmon resonance studies further confirm that the PTB-PIR binds stronger to IR than just the PTB domain, and that phosphorylations at Ser307, Ser312, Ser315, and Ser323 within the PIR domain result in abrogating the binding. Insulin-responsive cells containing the mutant IRS-1 with all these four serines changed into glutamates to mimic phosphorylations show decreased levels of phosphorylations in IR, IRS-1, and AKT compared to the wild-type IRS-1. Hydrogen-deuterium exchange mass spectrometry experiments indicating the PIR domain interacting with the N-terminal lobe and the hinge regions of the IR kinase domain further suggest the possibility that the IRS-1 PIR domain protects the IR from the PTP1B-mediated dephosphorylation. [ABSTRACT FROM AUTHOR]

Transporter research primarily relies on the canonical substrates of well-established transporters. This approach has limitations when studying transporters for the low-abundant micromolecules, such as micronutrients, and may not reveal physiological functions of the transporters. While d-serine, a trace enantiomer of serine in the circulation, was discovered as an emerging biomarker of kidney function, its transport mechanisms in the periphery remain unknown. Here, using a multi-hierarchical approach from body fluids to molecules, combining multi-omics, cell-free synthetic biochemistry, and ex vivo transport analyses, we have identified two types of renal d-serine transport systems. We revealed that the small amino acid transporter ASCT2 serves as a d-serine transporter previously uncharacterized in the kidney and discovered d-serine as a non-canonical substrate of the sodium-coupled monocarboxylate transporters (SMCTs). These two systems are physiologically complementary, but ASCT2 dominates the role in the pathological condition. Our findings not only shed light on renal d-serine transport, but also clarify the importance of non-canonical substrate transport. This study provides a framework for investigating multiple transport systems of various trace micromolecules under physiological conditions and in multifactorial diseases. [ABSTRACT FROM AUTHOR]

We previously showed that SerpinE2 and the serine protease HtrA1 modulate fibroblast growth factor (FGF) signaling in germ layer specification and head-to-tail development of Xenopus embryos. Here, we present an extracellular proteolytic mechanism involving this serpin-protease system in the developing neural crest (NC). Knockdown of SerpinE2 by injected antisense morpholino oligonucleotides did not affect the specification of NC progenitors but instead inhibited the migration of NC cells, causing defects in dorsal fin, melanocyte, and craniofacial cartilage formation. Similarly, overexpression of the HtrA1 protease impaired NC cell migration and the formation of NC-derived structures. The phenotype of SerpinE2 knockdown was overcome by concomitant downregulation of HtrA1, indicating that SerpinE2 stimulates NC migration by inhibiting endogenous HtrA1 activity. SerpinE2 binds to HtrA1, and the HtrA1 protease triggers degradation of the cell surface proteoglycan Syndecan-4 (Sdc4). Microinjection of Sdc4 mRNA partially rescued NC migration defects induced by both HtrA1 upregulation and SerpinE2 downregulation. These epistatic experiments suggest a proteolytic pathway by a double inhibition mechanism: SerpinE2 ┤HtrA1 protease ┤Syndecan-4 → NC cell migration. [ABSTRACT FROM AUTHOR]

Many organisms that utilize the Calvin-Benson-Bassham (CBB) cycle for autotrophic growth harbor metabolic pathways to remove and/or salvage 2-phosphoglycolate, the product of the oxygenase activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). It has been presumed that the occurrence of 2-phosphoglycolate salvage is linked to the CBB cycle, and in particular, the C2 pathway to the CBB cycle and oxygenic photosynthesis. Here, we examined 2-phosphoglycolate salvage in the hyperthermophilic archaeon Thermococcus kodakarensis, an obligate anaerobe that harbors a Rubisco that functions in the pentose bisphosphate pathway. T. kodakarensis harbors enzymes that have the potential to convert 2-phosphoglycolate to glycine and serine, and their genes were identified by biochemical and/or genetic analyses. 2-phosphoglycolate phosphatase activity increased 1.6-fold when cells were grown under microaerobic conditions compared to anaerobic conditions. Among two candidates, TK1734 encoded a phosphatase specific for 2-phosphoglycolate, and the enzyme was responsible for 80% of the 2-phosphoglycolate phosphatase activity in T. kodakarensis cells. The TK1734 disruption strain displayed growth impairment under microaerobic conditions, which was relieved upon addition of sodium sulfide. In addition, glycolate was detected in the medium when T. kodakarensis was grown under microaerobic conditions. The results suggest that T. kodakarensis removes 2-phosphoglycolate via a phosphatase reaction followed by secretion of glycolate to the medium. As the Rubisco in T. kodakarensis functions in the pentose bisphosphate pathway and not in the CBB cycle, mechanisms to remove 2-phosphoglycolate in this archaeon emerged independent of the CBB cycle. [ABSTRACT FROM AUTHOR]

Anti-inflammatory drugs have become the second-largest class of common drugs after anti-infective drugs in animal clinical care worldwide and are often combined with other drugs to treat fever and viral diseases caused by various factors. In our previous study, a novel serine protease inhibitor-encoding gene (MDSPI16) with improved anti-inflammatory activity was selected from a constructed suppressive subducted hybridization library of housefly larvae. This protein could easily induce an immune response in animals and had a short half-life, which limited its wide application in the clinic. Thus, in this study, mPEG-succinimidyl propionate (mPEG-SPA, Mw = 5 kDa) was used to molecularly modify the MDSPI16 protein, and the modified product mPEG-SPA-MDSPI16, which strongly inhibited elastase production, was purified. It had good stability and safety, low immunogenicity, and a long half-life, and the IC50 for elastase was 86 nM. mPEG-SPA-MDSPI16 effectively inhibited the expression of neutrophil elastase and decreased ROS levels. Moreover, mPEG-SPA-MDSPI16 exerted anti-inflammatory effects by inhibiting activation of the NF-κB signaling pathway and the MAPK signaling pathway in neutrophils. It also exerted therapeutic effects on a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. In summary, mPEG-SPA-MDSPI16 is a novel anti-inflammatory protein modified with PEG that has the advantages of safety, nontoxicity, improved stability, and strong anti-inflammatory activity in vivo and in vitro and is expected to become an effective anti-inflammatory drug. [ABSTRACT FROM AUTHOR]

In rice, there is a lack of comprehensive research on the functional aspects of the members of the serine hydroxymethyltransferase (SHMT) gene family. This study provides a comprehensive investigation of the SHMT gene family, covering phylogeny, gene structure, promoter analysis, expression analysis, subcellular localization, and protein interaction. Remarkably, we discovered a specific gene loss event occurred in the chloroplast-localized group IIa SHMTs in monocotyledons. However, OsSHMT3, which originally classified within cytoplasmic-localized group Ib, was found to be situated within chloroplasts in rice protoplasts. All five OsSHMTs are capable of forming homodimers, with OsSHMT3 being the only one able to form dimers with other OsSHMTs, except for OsSHMT1. It is proposed that OsSHMT3 functions as a mobile protein, collaborating with other OsSHMT proteins. Furthermore, the results of cis-acting element prediction and expression analysis suggested that members of the OsSHMT family could be involved in diverse stress responses and hormone regulation. Our study aims to provide novel insights for the future exploration of SHMTs. [ABSTRACT FROM AUTHOR]

Redesigning protein-protein interfaces is an important tool for developing therapeutic strategies. Interfaces can be redesigned by in silico screening, which allows for efficient sampling of a large protein space before experimental validation. However, computational costs limit the number of combinations that can be reasonably sampled. Here, we present combinatorial tyrosine (Y)/serine (S) selection (combYSelect), a computational approach combining in silico determination of the change in binding free energy (G) of an interface with a highly restricted library composed of just two amino acids, tyrosine and serine. We used combYSelect to design two immunoglobulin G (IgG) heterodimers--combYSelect1 (L368S/D399Y-K409S/T411Y) and combYSelect2 (D399Y/K447S-K409S/T411Y)--that exhibit near-optimal heterodimerization, without affecting IgG stability or function. We solved the crystal structures of these heterodimers and found that dynamic p-stacking interactions and polar contacts drive preferential heterodimeric interactions. Finally, we demonstrated the utility of our combYSelect heterodimers by engineering both a bispecific antibody and a cytokine trap for two unique therapeutic applications. [ABSTRACT FROM AUTHOR]