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Neutrophils are the first immune cells to reach inflamed sites and contribute to the pathogenesis of chronic inflammatory skin diseases. Yet, little is known about the pattern of neutrophil infiltration in inflamed skin in vivo and the mechanisms mediating their recruitment. Here, we provide insight into the dynamics of neutrophil infiltration in skin in response to acute or repeated inflammatory stress, highlighting a novel keratinocyte- and keratin 17 (K17)-dependent mechanism that regulates neutrophil recruitment to inflamed skin. We used the phorbol ester TPA and UVB, alone or in combination, to induce sterile inflammation in mouse skin. A single TPA treatment results in a neutrophil influx in the dermis that peaks at 12 h and resolves within 24 h. A subsequent TPA treatment or a UVB challenge, when applied 24 h but not 48 h later, accelerates, amplifies, and prolongs neutrophil infiltration. This transient amplification response (TAR) is mediated by local signals in inflamed skin, can be recapitulated in ex vivo culture, and involves the K17-dependent sustainment of protein kinase Cα (PKCα) activity and release of chemoattractants by stressed keratinocytes. K17 binds RACK1, a scaffold protein essential for PKCα activity. The N-terminal head domain of K17 is crucial for its association with RACK1 and regulation of PKCα activity. Analysis of RNAseq data reveals a signature consistent with TAR and PKCα activation in inflammatory skin diseases. These findings uncover a novel, keratin-dependent mechanism that amplifies neutrophil recruitment in skin under stress, with direct implications for inflammatory skin disorders. Neutrophils contribute to the pathogenesis of chronic inflammatory diseases, but the mechanisms underlying their recruitment to inflamed skin are unclear. This study shows that repeated acute stress to the skin amplifies a neutrophil infiltration response involving keratin 17 and PKCα. [ABSTRACT FROM AUTHOR]

Summary DNA sensors generally initiate innate immune responses through the production of type I interferons. While extensively studied for host defense against invading pathogens, emerging evidence highlights the involvement of DNA sensors in metabolic and cardiovascular diseases. Elevated levels of modified, damaged, or ectopically localized self‐DNA and non‐self‐DNA have been observed in patients and animal models with obesity, diabetes, fatty liver disease, and cardiovascular disease. The accumulation of cytosolic DNA aberrantly activates DNA signaling pathways, driving the pathological progression of these disorders. This review highlights the roles of specific DNA sensors, such as cyclic AMP‐GMP synthase and stimulator of interferon genes (cGAS‐STING), absent in melanoma 2 (AIM2), toll‐like receptor 9 (TLR9), interferon gamma‐inducible protein 16 (IFI16), DNA‐dependent protein kinase (DNA‐PK), and DEAD‐box helicase 41 (DDX41) in various metabolic disorders. We explore how DNA signaling pathways in both immune and non‐immune cells contribute to the development of these diseases. Furthermore, we discuss the intricate interplay between metabolic stress and immune responses, offering insights into potential therapeutic targets for managing metabolic and cardiovascular disorders. Understanding the mechanisms of DNA sensor signaling in these contexts provides a foundation for developing novel interventions aimed at mitigating the impact of these pervasive health issues. [ABSTRACT FROM AUTHOR]

Background: Intracellular sensing of lipopolysaccharide (LPS) is essential for the immune response against gram-negative bacteria and results in activation of caspase-11 and pyroptotic cell death with fatal consequences in sepsis. We found the neuronal guidance receptor plexin C1 (PLXNC1) influences the intracellular response to LPS. Methods: We employed a murine model of sepsis via cecal ligation and binding (CLP), using PLXNC1-/- mice and littermate controls, and additionally transfected murine bone-marrow-derived macrophages (BMDMs) from both genotypes with LPS to achieve activation of the noncanonical inflammasome ex vivo. Additionally, we transfected the PLXNC1 ligand SL4c-d in vivo and ex vivo to examine its effect on intracellular LPS response. Results: We found the neuronal guidance receptor PLXNC1 dampens the intracellular response to LPS by interacting with adenylate cyclase 4 (ADCY4) and protein kinase A activity, which in turn diminishes caspase-11 expression. The absence of PLXNC1 results in excessive inflammation marked by increased cytokine release, increased secondary organ injury and reduced sepsis survival in a murine sepsis model induced by CLP. Notably, administration of SL4c-d—peptide ligand of PLXNC1—reduces the inflammatory response during CLP-induced sepsis and improves survival. Conclusions: These results elucidate a previously unknown mechanism for PLXNC1 suppressing excessive noncanonical inflammasome activity and offer a new potential target for treatment of sepsis with its detrimental effects. [ABSTRACT FROM AUTHOR]

Metabolic‐associated fatty liver disease (MAFLD) has become one of the most widespread metabolic diseases nowadays, while no definitive agent is approved for practical treatment. Given excessive lipid deposition and cellular oxidative stress are two main inducers of MAFLD, developing synergistic therapeutic agents that enhance lipid metabolism and antioxidative ability are effective routes for MAFLD therapy. Herein, a novel kind of bio‐functional carbon dots (MTCDs) derived from metformin and tea polyphenols based on a fused pharmacophore strategy is developed. The surface of MTCDs retains abundant phenolic hydroxyl and guanidine groups, which are designed to reduce both lipid deposition and oxidative stress in the liver. Moreover, by finely controlling the surface charge, MTCDs exhibit excellent lysosome targeting functionality with favorable biocompatibility and low biotoxicity. Mechanistical studies further reveal that MTCDs treatment protects lysosomes from oxidative stress damage and activates hepatocyte AMP‐activated protein kinase signaling, which initiates lipophagy progress to accelerate lipolysis and lipid consumption. Collectively, these studies propose an effective “two birds with one stone” tool for MAFLD synergistic therapy and suggest a viable strategy for multi‐pharmacophore agent development. [ABSTRACT FROM AUTHOR]

More than 10 million people suffer from lung diseases caused by the pathogenic fungus Aspergillus fumigatus. Azole antifungals represent first-line therapeutics for most of these infections but resistance is rising, therefore the identification of antifungal targets whose inhibition synergises with the azoles could improve therapeutic outcomes. Here, we generate a library of 111 genetically barcoded null mutants of Aspergillus fumigatus in genes encoding protein kinases, and show that loss of function of kinase YakA results in hypersensitivity to the azoles and reduced pathogenicity. YakA is an orthologue of Candida albicans Yak1, a TOR signalling pathway kinase involved in modulation of stress responsive transcriptional regulators. We show that YakA has been repurposed in A. fumigatus to regulate blocking of the septal pore upon exposure to stress. Loss of YakA function reduces the ability of A. fumigatus to penetrate solid media and to grow in mouse lung tissue. We also show that 1-ethoxycarbonyl-beta-carboline (1-ECBC), a compound previously shown to inhibit C. albicans Yak1, prevents stress-mediated septal spore blocking and synergises with the azoles to inhibit A. fumigatus growth. Azole antifungals are used to treat lung diseases caused by the pathogenic fungus Aspergillus fumigatus, but resistance is rising. Here, the authors generate a library of >100 protein kinase mutants of A. fumigatus, and show that loss of function or pharmacological inhibition of kinase YakA results in hypersensitivity to azoles and reduced pathogenicity. [ABSTRACT FROM AUTHOR]

Chemodynamic therapy (CDT) presents promise as a cancer treatment method, but its efficacy faces challenges due to the inefficient Fenton catalytic reaction, where the transition metals' conversion from high to low valence states acts as the rate‐limiting step. Here, a strategy employing radioiodine is introduced to facilitate the valence conversion of transition metals for CDT enhancement. Iron‐based metal‐organic framework (MOF) nanoparticles (NPs) are synthesized labeled with radioiodine‐125 (125I), referred to as 125I‐MIL‐88B(Fe) NPs. These NPs possess a porous structure capable of concentrating and catalyzing H2O2 to generate highly toxic hydroxyl radicals (·OH). Furthermore, 125I can continuously produce hydrated electrons (eaq−) in aqueous environments, promoting the conversion of Fe3+/Fe2+ to boost ·OH production. In vitro and in vivo experiments validate the enhanced CDT effect on pancreatic cancer, driven by the reactive oxygen species (ROS)/mitogen‐activated protein kinase (MAPK)/p53 pathway‐mediated cell apoptosis. The radioiodine‐mediated electron‐supplying strategy not only amplifies the effectiveness of CDT but also unlocks new potential applications for radionuclides. [ABSTRACT FROM AUTHOR]

AbstractBackgroundAimMethodologyResultsConclusion\nKey pointsThe inconvenience of social and behavioural deficits after cerebral ischaemia reperfusion (I/R) injury is still not well documented.We aimed to study the protective effect of preconditioning swimming exercise combined with melatonin against cerebral I/R induced injury.Sixty rats were allocated into 6 groups; groups I and II served as control. Groups 3,4,5,6 subjected to bilateral carotid ligation for 30 minutes (min.) followed by reperfusion. Group 3 left untreated while groups 4 and 6; underwent swimming exercise 30 min/day, five days a week for three weeks before the surgery. Groups 5 and 6 treated with melatonin 30 minutes before the operation, then, all rats in groups 4, 5,6 were subjected to I/R. After that, groups 5 and 6 treated with 2nd dose of melatonin 30 minutes after reperfusion.Combined strategy exhibited the most neuroprotective effect through prevention of cerebral I/R induced inflammation, oxidative stress and apoptosis with subsequent improvement in socio behaviour deficits and enhanced Glial cell proliferative capacity.The protective contribution of combined strategy is associated with modulation in Macrophage‐stimulating 1/mitogen-activated protein kinase/extracellular signal-regulated kinase (MST1/MAPK/ERK) pathway which may explain, at least in part, its protective potential.Preconditioning swimming exercise combined with melatonin protected against cerebral I/R induced socio-behavioural deficit.Cerebral I/R induced pathophysiological alterations in Prefrontal cortical neurons (PFC) are prevented by combined Preconditioning swimming exercise and melatoninCombined Preconditioning swimming exercise/melatonin in cerebral I/R modulates MST1/MAPK/ERK signalling pathwayCombined Preconditioning swimming exercise/melatonin inhibit inflammation, oxidative stress and apoptosis, thus enhance Glial cell proliferative capacity in I/R induced injury in PFC neurons.Preconditioning swimming exercise combined with melatonin protected against cerebral I/R induced socio-behavioural deficit.Cerebral I/R induced pathophysiological alterations in Prefrontal cortical neurons (PFC) are prevented by combined Preconditioning swimming exercise and melatoninCombined Preconditioning swimming exercise/melatonin in cerebral I/R modulates MST1/MAPK/ERK signalling pathwayCombined Preconditioning swimming exercise/melatonin inhibit inflammation, oxidative stress and apoptosis, thus enhance Glial cell proliferative capacity in I/R induced injury in PFC neurons. [ABSTRACT FROM AUTHOR]

The PI3K/AKT/GSK-3β signaling pathway plays a pivotal role in numerous physiological and pathological processes, including cell proliferation, apoptosis, differentiation, and metabolic regulation. Aberrant activation of the PI3K/AKT pathway is intricately linked to development of tumor. GSK-3β, belonging to the serine/threonine protein kinase family, is crucial in the pathogenesis of liver cancer. As a key rate-limiting enzyme in the glucose metabolism pathway, GSK-3β significantly impacts the growth, proliferation, metastasis, and apoptosis of liver cancer cells. It is also implicated in chemotherapy resistance. Elevated expression of GSK-3β diminishes the sensitivity of liver cancer cells to chemotherapeutic agents, thereby playing a substantial role in the development of drug resistance. Consequently, targeting of GSK-3β, particularly within the PI3K/AKT signaling pathway, is regarded as a promising therapeutic strategy for liver cancer. The precise identification and subsequent modulation of this pathway represent a substantial potential for innovative clinical interventions in the management of liver cancer. [ABSTRACT FROM AUTHOR]

The involvement of inwardly rectifying potassium channel 4.1 (Kir4.1) in neuropathic pain has been established. However, there is limited understanding of the downstream mechanism through which Kir4.1 contributes to orofacial neuropathic pain. The objective of this study was to examine the regulation of Kir4.1 on the expression of pannexin 3 (Panx3) in the trigeminal ganglion (TG) and the underlying mechanism in the context of orofacial neuropathic pain caused by chronic constriction injury of the infraorbital nerve (CCI‐ION). The study observed a significant increase in Panx3 expression in the TG of mice with CCI‐ION. Inhibition of Panx3 in the TG of CCI‐ION mice resulted in alleviation of orofacial mechanical allodynia. Furthermore, conditional knockdown (CKD) of Kir4.1 in the TG of both male and female mice led to mechanical allodynia and upregulation of Panx3 expression. Conversely, overexpression of Kir4.1 decreased Panx3 levels in the TG and relieved mechanical allodynia in CCI‐ION mice. In addition, silencing Kir4.1 in satellite glial cells (SGCs) decreased Panx3 expression and increased the phosphorylation of P38 MAPK. Moreover, silencing Kir4.1 in SGCs increased the levels of reactive oxygen species (ROS). The elevated phosphorylation of P38 MAPK resulting from Kir4.1 silencing was inhibited by using a superoxide scavenger known as the tempol. Silencing Panx3 in the TG in vivo attenuated the mechanical allodynia caused by Kir4.1 CKD. In conclusion, these findings suggest that the reduction of Kir4.1 promotes the expression of Panx3 by activating the ROS‐P38 MAPK signalling pathway, thus contributing to the development of orofacial neuropathic pain. [ABSTRACT FROM AUTHOR]

Mitogen‐activated extracellular signal‐regulated kinase inhibitors (MEKi) represent a promising new therapy for pediatric patients with low‐grade gliomas, which frequently have abnormal signaling within the mitogen‐activated protein kinase (MAP kinase) pathway. However, understanding of long‐term efficacy and toxicity is limited in pediatric glioma patients. This article describes a rare presentation of a widespread cutaneous infection with Mycobacterium chelonae in a pediatric patient with a low‐grade glioma treated with trametinib. [ABSTRACT FROM AUTHOR]

Cancer cells exhibit a unique metabolic preference for the glycolytic pathway over oxidative phosphorylation for maintaining the tumor microenvironment. Lactate dehydrogenase A (LDHA) is a key enzyme that facilitates glycolysis by converting pyruvate to lactate and has been shown to be upregulated in multiple cancers due to the hypoxic tumor microenvironment. Diclofenac (DCF), a nonsteroidal anti‐inflammatory drug, has been shown to exhibit anticancer effects by interfering with the glucose metabolism pathway. However, the specific targets of this drug remain unknown. Using in silico, biochemical, and biophysical studies, we show that DCF binds to LDHA adjacent to the substrate binding site and inhibits its activity in a dose‐dependent and allosteric manner in HeLa cells. Thus, DCF inhibits the hypoxic microenvironment and induces apoptosis‐mediated cell death. DCF failed to induce cytotoxicity in HeLa cells when LDHA was knocked down, confirming that DCF exerts its antimitotic effects via LDHA inhibition. DCF‐induced LDHA inhibition alters pyruvate, lactate, NAD+, and ATP production in cells, and this could be a possible mechanism through which DCF inhibits glucose uptake in cancer cells. DCF‐induced ATP deprivation leads to mitochondria‐mediated oxidative stress, which results in DNA damage, lipid peroxidation, and apoptosis‐mediated cell death. Reduction in intracellular ATP levels additionally activates the sensor kinase, adenosine monophosphate‐activated protein kinase (AMPK), which further downregulates phosphorylated ribosomal S6 kinase (p‐S6K), leading to apoptosis‐mediated cell death. We find that in LDHA knocked down cells, intracellular ATP levels were depleted, resulting in the inhibition of p‐S6K, suggesting the involvement of DCF‐induced LDHA inhibition in the activation of the AMPK/S6K signaling pathway. [ABSTRACT FROM AUTHOR]

Simple Summary: Treatment with ARSI results in an increased expression of the TLK1B splice variant and consequent activation of the TLK1>NEK1>YAP axis. We now provide important details of the significance of the NEK1-mediated phosphorylation of the YAP-Y407F residue for its nuclear localization and transcriptional output. Furthermore, we study the effect of the pharmacologic inhibition of this pathway in a xenograft model that readily converts from androgen-dependent to castration-resistant (CRPC) prostate cancer, as a first approach to translating our work toward a clinical investigation. Despite some advances in controlling the progression of prostate cancer (PCa) that is refractory to the use of ADT/ARSI, most patients eventually succumb to the disease, and there is a pressing need to understand the mechanisms that lead to the development of CRPC. A common mechanism is the ability to integrate AR signals from vanishing levels of testosterone, with the frequent participation of YAP as a co-activator, and pointing to the deregulation of the Hippo pathway as a major determinant. We have recently shown that YAP is post-transcriptionally activated via the TLK1>NEK1 axis by stabilizing phosphorylation at Y407. We are now solidifying this work by showing the following: (1) The phosphorylation of Y407 is critical for YAP retention/partition in the nuclei, and J54 (TLK1i) reverses this along with YAP-Y407 dephosphorylation. (2) The enhanced degradation of (cytoplasmic) YAP is increased by J54 counteracting its Enzalutamide-induced accumulation. (3) The basis for all these effects, including YAP nuclear retention, can be explained by the stronger association of pYAP-Y407 with its transcriptional co-activators, AR and TEAD1. (4) We demonstrate that ChIP for GFP-YAP-wt, but hardly for the GFP-YAP-Y407F mutant, at the promoters of typical ARE- and TEAD1-driven genes is readily detected but becomes displaced after treatment with J54. (5) While xenografts of LNCaP cells show rapid regression following treatment with ARSI+J54, in the VCaP model, driven by the TMPRSS2-ERG oncogenic translocation, tumors initially respond well to the combination but subsequently recur, despite the continuous suppression of pNek1-T141 and pYAP-Y407. This suggests an alternative parallel pathway for CRPC progression for VCaP tumors in the long term, which may be separate from the observed ENZ-driven YAP deregulation, although clearly some YAP gene targets like PD-L1, that are found to accumulate following prolonged ENZ treatment, are still suppressed by the concomitant addition of J54. [ABSTRACT FROM AUTHOR]

Simple Summary: Despite major advances in treating non-small-cell lung cancer (NSCLC), the five-year survival rates for patients without specific genetic mutations remain low. This study aims to find better ways to treat these patients. We focused on a protein called Aurora kinase A (AURKA), which our prior study suggested may play a role in modulating resistance to the common cancer drug cisplatin. We looked at how AURKA affects the sensitivity of NSCLC cells to platinum-based chemotherapy and radiation. In lab tests, AURKA levels increased after cisplatin treatment. Blocking AURKA with a drug called alisertib or using a genetic method made cisplatin and radiation more effective, causing tumors to shrink in mouse models. The treated cancer cells showed more DNA damage and underwent cell death. Blocking AURKA also increased markers that help the immune system recognize cancer. Our study suggests that combining AURKA inhibitors with other treatments could improve outcomes for NSCLC patients. Despite major advances in non-small-cell lung cancer (NSCLC) treatment, the five-year survival rates for patients with non-oncogene-driven tumors remain low, necessitating combinatory approaches to improve outcomes. Our prior high-throughput RNAi screening identified Aurora kinase A (AURKA) as a potential key player in cisplatin resistance. In this study, we investigated AURKA's role in platinum and radiation sensitivity in multiple NSCLC cell lines and xenograft mouse models, as well as its effect on immune checkpoints, including PD-L1, B7x, B7-H3, and HHLA2. Of 94 NSCLC patient tumor specimens, 91.5% tested positive for AURKA expression, with 34% showing moderate-to-high levels. AURKA expression was upregulated following cisplatin treatment in NSCLC cell lines PC9 and A549. Both AURKA inhibition by alisertib and inducible AURKA knockdown potentiated the cytotoxic effects of cisplatin and radiation, leading to tumor regression in doxycycline-inducible xenograft mice. Co-treated cells exhibited increased DNA double-strand breaks, apoptosis, and senescence. Additionally, AURKA inhibition alone by alisertib increased PD-L1 and B7-H3 expression. In conclusion, our study demonstrates that AURKA inhibition enhances the efficacy of platinum-based chemotherapy in NSCLC cells and modulates the expression of multiple immune checkpoints. Therefore, combinatory regimens with AURKA inhibitors should be strategically designed and further studied within the evolving landscape of chemo-immunotherapy. [ABSTRACT FROM AUTHOR]

Rosa davurica Pall. is widely used in traditional oriental herbal therapy, but its components and molecular mechanisms of action remain unclear. This study investigates the antidiabetic potential of Rosa davurica Pall. root extract (RDR) and elucidates its underlying molecular mechanisms with in vitro and in vivo models. Data from the current study show that RDR exhibits strong antioxidant activity and glucose homeostasis regulatory effects. It significantly impacts glucose homeostasis in C2C12 skeletal muscle cells by inhibiting α-glucosidase activity. Further molecular mechanistic studies revealed that RDR promoted glucose uptake by phosphorylation of AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC), but not Phosphatidylinositol 3-kinase (PI 3-kinase)/Akt in C2C12 skeletal muscle cells. These actions increased the expression and translocation of glucose transporter type 4 (GLUT4) to the plasma membrane. In addition, RDR treatment in the STZ-induced diabetic rats remarkably improved the low body weight, polydipsia, polyphagia, hyperglycemia, and islet architecture and increased the insulin/glucose ratio. The liver (ALT and AST) and kidney marker enzyme (BUN and creatinine) levels were restored by RDR treatment as well. Phytochemical analysis identified eight major constituents in RDR, crucial for its antioxidant and antidiabetic activity. Through the molecular docking of representative glucose transporter GLUT4 with these compounds, it was confirmed that the components of RDR had a significantly high binding score in terms of structural binding. These findings from the current study highlight the antidiabetic effects of RDR. Collectively, our data suggest that RDR might be a potential pharmaceutical natural product for diabetic patients. [ABSTRACT FROM AUTHOR]

Ribosomal protein S6 kinases belong to a family of highly conserved enzymes in eukaryotes that regulate cell growth, proliferation, survival, and the stress response. It is well established that the activation and downstream signalling of p70S6Ks involve multiple phosphorylation events by key regulators of cell growth, survival, and energy metabolism. Here, we report for the first time the covalent modification of p70S6K1 by coenzyme A (CoA) in response to oxidative stress, which regulates its kinase activity. The site of CoA binding (CoAlation) was mapped by mass spectrometry to cysteine 217 (Cys217), located in the kinase activation loop and only one amino acid away from the tripeptide DFG motif, which facilitates ATP-binding. The CoAlation of recombinant p70S6K1 was demonstrated in vitro and was shown to inhibit its kinase activity. Our molecular docking and dynamics analysis revealed the most likely mode for CoA binding to p70S6K1. This mechanism involves the non-covalent binding of the CoA ADP moiety to the p70S6K1 nucleotide-binding pocket, positioning the CoA thiol group in close proximity to form a covalent bond with the surface-exposed Cys217 residue. These findings support a "dual anchor" mechanism for protein kinase inhibition by CoAlation in cellular response to oxidative stress. Furthermore, the inhibition of S6K1 by CoAlation may open new avenues for developing novel inhibitors. [ABSTRACT FROM AUTHOR]

The effects of enhanced late INa, a persistent component of the Na+ channel current, on the intracellular ion dynamics and the automaticity of the pulmonary vein cardiomyocytes were studied with fluorescent microscopy. Anemonia viridis toxin II (ATX- II), an enhancer of late INa, caused increases in the basal Na+ and Ca2+ concentrations, increases in the number of Ca2+ sparks and Ca2+ waves, and the generation of repetitive Ca2+ transients. These phenomena were inhibited by eleclazine, a blocker of the late INa; SEA0400, an inhibitor of the Na+/Ca2+ exchanger (NCX); H89, a protein kinase A (PKA) inhibitor; and KN-93, a Ca2+/calmodulin-dependent protein kinase II (CaMKII) inhibitor. These results suggest that enhancement of late INa in the pulmonary vein cardiomyocytes causes disturbance of the intracellular ion environment through activation of the NCX and Ca2+-dependent enzymes. Such mechanisms are probably involved in the ectopic electrical activity of the pulmonary vein myocardium. [ABSTRACT FROM AUTHOR]

Cancer stem cells represent a resilient subset within the tumor microenvironment capable of differentiation, regeneration, and resistance to chemotherapeutic agents, often using dormancy as a shield. Their unique properties, including drug resistance and metastatic potential, pose challenges for effective targeting. These cells exploit certain metabolic processes for their maintenance and survival. One of these processes is autophagy, which generally helps in energy homeostasis but when hijacked by CSCs can help maintain their stemness. Thus, it is often referred as an Achilles heel in CSCs, as certain cancers tend to depend on autophagy for survival. Autophagy, while crucial for maintaining stemness in cancer stem cells (CSCs), can also serve as a vulnerability in certain contexts, making it a complex target for therapy. Regulators of autophagy like AMPK (5′ adenosine monophosphate-activated protein kinase) also play a crucial role in maintaining CSCs stemness by helping CSCs in metabolic reprogramming in harsh environments. The purpose of this review is to elucidate the interplay between autophagy and AMPK in CSCs, highlighting the challenges in targeting autophagy and discussing therapeutic strategies to overcome these limitations. This review focuses on previous research on autophagy and its regulators in cancer biology, particularly in CSCs, addresses the remaining unanswered questions, and potential targets for therapy are also brought to attention. [ABSTRACT FROM AUTHOR]

Herpesviral protein kinases, such as the therapy-relevant pUL97 of human cytomegalovirus (HCMV), are important for viral replication efficiency as well as pathogenesis, and represent key antiviral drug targets. HCMV pUL97 is a viral cyclin-dependent kinase (CDK) ortholog, as it shares functional and structural properties with human CDKs. Recently, the formation of vCDK/pUL97–cyclin complexes and the phosphorylation of a variety of viral and cellular substrate proteins has been demonstrated. Genetic mapping and structural modeling approaches helped to define two pUL97 interfaces, IF1 and IF2, responsible for cyclin binding. In particular, the regulatory importance of interactions between vCDK/pUL97 and host cyclins as well as CDKs has been highlighted, both as determinants of virus replication and as a novel drug-targeting option. This aspect was substantiated by the finding that virus replication was impaired upon cyclin type H knock-down, and that such host-directed interference also affected viruses resistant to existing therapies. Beyond the formation of binary interactive complexes, a ternary pUL97–cyclin H–CDK7 complex has also been described, and in light of this, an experimental trans-stimulation of CDK7 activity by pUL97 appeared crucial for virus–host coregulation. In accordance with this understanding, several novel antiviral targeting options have emerged. These include kinase inhibitors directed to pUL97, to host CDKs, and to the pUL97–cyclin H interactive complexes. Importantly, a statistically significant drug synergy has recently been reported for antiviral treatment schemes using combinations of pharmacologically relevant CDK7 and vCDK/pUL97 inhibitors, including maribavir. Combined, such findings provide increased options for anti-HCMV control. This review focuses on regulatory interactions of vCDK/pUL97 with the host cyclin–CDK apparatus, and it addresses the functional relevance of these key effector complexes for viral replication and pathogenesis. On this basis, novel strategies of antiviral drug targeting are defined. [ABSTRACT FROM AUTHOR]

Loss of function mutations in the checkpoint kinase gene CHEK2 are associated with increased risk of breast and other cancers. Most of the 3,188 unique amino acid changes that can result from non-synonymous single nucleotide variants (SNVs) of CHEK2, however, have not been tested for their impact on the function of the CHEK2-enocded protein (CHK2). One successful approach to testing the function of variants has been to test for their ability to complement mutations in the yeast ortholog of CHEK2, RAD53. This approach has been used to provide functional information on over 100 CHEK2 SNVs and the results align with functional assays in human cells and known pathogenicity. Here we tested all but two of the 4,887 possible SNVs in the CHEK2 open reading frame for their ability to complement RAD53 mutants using a high throughput technique of deep mutational scanning (DMS). Among the non-synonymous changes, 770 were damaging to protein function while 2,417 were tolerated. The results correlate well with previous structure and function data and provide a first or additional functional assay for all the variants of uncertain significance identified in clinical databases. Combined, this approach can be used to help predict the pathogenicity of CHEK2 variants of uncertain significance that are found in susceptibility screening and could be applied to other cancer risk genes. Author summary: Variations in gene sequences account for many of the phenotypic differences between individuals, including different susceptibilities to diseases like cancer. Individuals who inherit specific variants in the CHEK2 gene, for example, have increased risk of developing breast cancer and other cancers. These cancer-associated variants all abolish the normal activity of the CHEK2-encoded protein, a protein kinase called Chk2. Most of the CHEK2 variants found in individuals, however, have an unknown effect on the function of the Chk2 protein, and therefore an unknown potential role in cancer. This is because it is cumbersome to individually make and test each newly identified variant to see whether it affects protein function. Here we use an efficient version of a technique called deep mutational scanning to test nearly all possible CHEK2 single nucleotide variants for their impact on Chk2 protein function. Analyses of the resulting data indicate that it will be useful for developing models to predict the cancer risk in individuals who inherit any CHEK2 variants. This study also demonstrates a viable efficient approach to study variants of other genes, including other cancer related genes. [ABSTRACT FROM AUTHOR]

The accuracy of cell division requires precise regulation of the cellular machinery governing DNA/genome duplication, ensuring its equal distribution among the daughter cells. The control of the centrosome cycle is crucial for the formation of a bipolar spindle, ensuring error‐free segregation of the genome. The cell and centrosome cycles operate in close synchrony along similar principles. Both require a single duplication round in every cell cycle, and both are controlled by the activity of key protein kinases. Nevertheless, our comprehension of the precise cellular mechanisms and critical regulators synchronizing these two cycles remains poorly defined. Here, we present our hypothesis that the spatiotemporal regulation of a dynamic equilibrium of mitotic kinases activities forms a molecular clock that governs the synchronous progression of both the cell and the centrosome cycles. [ABSTRACT FROM AUTHOR]

Background: While melanomas commonly harbor losses of 9p21, on which CDKN2A resides, the presence of additional tumor suppressor elements at this locus is incompletely characterized. Here we assess the expression levels and functional role of microRNA-876-3p (miR-876), whose gene also maps to 9p21. Methods: Expression of miR-876 was assessed in human tissues and cell lines using quantitative miRNA reverse transcriptase polymerase chain reaction (qRT-PCR). MIR876 copy number was determined in The Cancer Genome Atlas (TCGA) melanoma cohort. The consequences of regulation of miR-876 expression were assessed on melanoma cell colony formation, migration, invasion, apoptosis, cell cycle progression, and drug sensitivity in culture, and on in vivo tumor growth in a xenograft model. Genome-wide transcriptomic changes induced by miR-876 overexpression were determined using RNA sequencing (RNA-Seq). Results: miR-876 expression was significantly decreased in primary melanoma samples when compared with nevi, and in human melanoma cell lines when compared with human melanocytes. Analysis of the TCGA cohort revealed deletions in MIR876 in > 50% of melanomas. miR-876 overexpression resulted in decreased melanoma cell colony formation, migration, and invasion, which was accompanied by cell cycle arrest and increased apoptosis. Intra-tumoral injections of miR-876 significantly suppressed melanoma growth in vivo. RNA-Seq analysis of miR-876-treated tumors revealed downregulation of several growth-promoting genes, along with upregulation of tumor suppressor genes, which was confirmed by qRT-PCR analysis. Computational analyses identified MAPK1 (or ERK2) as a possible target of miR-876 action. Overexpression of miR-876 significantly suppressed luciferase expression driven by the MAPK1/ERK2 3' UTR, and resulted in decreased ERK protein expression in melanoma cells. MAPK1/ERK2 cDNA overexpression rescued the effects of miR-876 on melanoma colony formation. miR-876 overexpression sensitized melanoma cells to treatment with the BRAF inhibitor vemurafenib. Conclusions: These studies identify miR-876 as a distinct tumor suppressor on 9p21 that is inactivated in melanoma and suggest miR-876 loss as an additional mechanism to activate ERK and the mitogen activated protein kinase (MAPK) pathway in melanoma. In addition, they suggest the therapeutic potential of combining miR-876 overexpression with BRAF inhibition as a rational therapeutic strategy for melanoma. [ABSTRACT FROM AUTHOR]

During Hedgehog (Hh) signal transduction in development and disease, the atypical G protein-coupled receptor (GPCR) SMOOTHENED (SMO) communicates with GLI transcription factors by binding the protein kinase A catalytic subunit (PKA-C) and physically blocking its enzymatic activity. Here, we show that GPCR kinase 2 (GRK2) orchestrates this process during endogenous mouse and zebrafish Hh pathway activation in the primary cilium. Upon SMO activation, GRK2 rapidly relocalizes from the ciliary base to the shaft, triggering SMO phosphorylation and PKA-C interaction. Reconstitution studies reveal that GRK2 phosphorylation enables active SMO to bind PKA-C directly. Lastly, the SMO-GRK2-PKA pathway underlies Hh signal transduction in a range of cellular and in vivo models. Thus, GRK2 phosphorylation of ciliary SMO and the ensuing PKA-C binding and inactivation are critical initiating events for the intracellular steps in Hh signaling. More broadly, our study suggests an expanded role for GRKs in enabling direct GPCR interactions with diverse intracellular effectors. The hedgehog signal transduction pathway has an important role in development; it proceeds through the atypical GPCR protein SMOOTHENED (SMO), which regulates the transcription factor GLI by direct binding to PKA-C. This study shows that the GPCR kinase 2 activates SMO in primary cilia, allowing its binding to PKA-C and pathway activation in various cellular and in vivo models. [ABSTRACT FROM AUTHOR]

CDKL5 Deficiency Disorder (CDD) is a debilitating epileptic encephalopathy disorder affecting young children with no effective treatments. CDD is caused by pathogenic variants in Cyclin-Dependent Kinase-Like 5 (CDKL5), a protein kinase that regulates key phosphorylation events in neurons. For therapeutic intervention, it is essential to understand molecular pathways and phosphorylation targets of CDKL5. Using an unbiased phosphoproteomic approach we identified novel targets of CDKL5, including GTF2I, PPP1R35, GATAD2A and ZNF219 in human iPSC-derived neuronal cells. The phosphoserine residue in the target proteins lies in the CDKL5 consensus motif. We validated direct phosphorylation of GTF2I and PPP1R35 by CDKL5 using complementary approaches. GTF2I controls axon guidance, cell cycle and neurodevelopment by regulating expression of neuronal genes. PPP1R35 is critical for centriole elongation and cilia morphology, processes that are impaired in CDD. PPP1R35 interacts with CEP131, a known CDKL5 phospho-target. GATAD2A and ZNF219 belong to the Nucleosome Remodelling Deacetylase (NuRD) complex, which regulates neuronal activity-dependent genes and synaptic connectivity. In-depth knowledge of molecular pathways regulated by CDKL5 will allow a better understanding of druggable disease pathways to fast-track therapeutic development. [ABSTRACT FROM AUTHOR]

Fiber length (FL) and strength (FS) are the core indicators for evaluating cotton fiber quality. The corresponding stages of fiber elongation and secondary wall thickening are of great significance in determining FL and FS formation, respectively. QTL mapping and high-throughput sequencing technology have been applied to dissect the molecular mechanism of fiber development. In this study, 15 cotton chromosome segment substitution lines (CSSLs) with significant differences in FL and FS, together with their recurrent parental Gossypium hirsutum line CCRI45 and donor parent G. barbadense line Hai1, were chosen to conduct RNA-seq on developing fiber samples at 10 days post anthesis (DPA) and 20 DPA. Differentially expressed genes (DEGs) were obtained via pairwise comparisons among all 24 samples (each one with three biological repeats). A total of 969 DEGs related to FL-high, 1285 DEGs to FS-high, and 997 DEGs to FQ-high were identified. The functional enrichment analyses of them indicated that the GO terms of cell wall structure and ROS, carbohydrate, and phenylpropanoid metabolism were significantly enriched, while the GO terms of glucose and polysaccharide biosynthesis, and brassinosteroid and glycosylphosphatidylinositol metabolism could make great contributions to FL and FS formation, respectively. Weighted gene co-expressed network analyses (WGCNA) were separately conducted for analyzing FL and FS traits, and their corresponding hub DEGs were screened in significantly correlated expression modules, such as EXPA8, XTH, and HMA in the fiber elongation and WRKY, TDT, and RAC-like 2 during secondary wall thickening. An integrated analysis of these hub DEGs with previous QTL identification results successfully identified a total of 33 candidate introgressive DEGs with non-synonymous mutations between the Gh and Gb species. A common DEG encoding receptor-like protein kinase 1 was reported to likely participate in fiber secondary cell thickening regulation by brassionsteroid signaling. Such valuable information was conducive to enlightening the developing mechanism of cotton fiber and also provided an abundant gene pool for further molecular breeding. [ABSTRACT FROM AUTHOR]

Endothelialization is important for offering an anticoagulant surface, which is crucial for the construction of tissue‐engineered heart valves. Silk sericin is extensively investigated in the biomedical field due to its remarkable biological activities and diverse functional groups, favoring chemical modifications for the formation of versatile constructs. Herein, a sericin covalently modified valve (SCMV) is successfully fabricated by coupling maleylated silk sericin (MSS) with thiolated decellularized heart valve (DHV) through a Michael addition reaction. The results demonstrate that SCMV exhibits a smooth surface, higher hydrophilicity, and excellent resistance to platelets adhesion compared to DHV. Additionally, SCMV promotes endothelial cells (ECs) adhesion under both static and flow conditions and enhances their survival in a mouse subcutaneous implant model. The study also discovered that MSS‐stimulated ECs exhibit increased RhoA activation, expression of rho‐associated protein kinase 2 (ROCK2) and phosphorylated myosin light chain 2 (MLC2), actin polymerization, and cell adhesion; whereas actin organization and cell adhesion are significantly reduced by treatment with Y‐27632, a ROCK inhibitor. Furthermore, several integrin subunits, including α1, α2, α3, α5, α6, β1, β3, and β5, are involved in this regulatory process. Collectively, the findings highlight the potential application of silk sericin in promoting endothelialization of DHV while uncovering novel mechanisms underlying its regulatory effect on ECs adhesion. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is widely recognized as the prevailing joint disease associated with aging. The ketogenic diet (KD) has been postulated to impede the advancement of various inflammatory ailments. β‐Hydroxybutyrate (βOHB), a prominent constituent of ketone bodies, has recently been proposed to possess crucial signaling capabilities. In this study, we propose to explore the role and mechanism of βOHB in OA. Tissue staining and inflammatory factor assay were employed to evaluate the impacts of KD and βOHB on OA rats. The oxidative stress conditions in chondrocytes were induced using tert‐butyl hydroperoxide (TBHP). The mechanisms were determined using the siRNA of hydroxycarboxylic acid receptor 2 (HCAR2), the antagonist of adenosine monophosphate‐activated protein kinase (AMPK), and the inhibitor of mitophagy. The administration of KD demonstrated a reduction in pathological damage to cartilage, as well as a decrease in plasma levels of inflammatory factors. Furthermore, it resulted in an increase in the concentration of βOHB in the blood and synovial fluid. In vitro experiments showed that βOHB facilitated mitophagy and adenosine triphosphate production. Besides, βOHB mitigated chondrocyte senescence, inflammatory factors secretion, extracellular matrix degradation, and apoptosis induced by TBHP. Subsequent investigations indicated that the protective effects of βOHB were no longer observed following the knockdown of HCAR2, the antagonist of AMPK, or the inhibitor of mitophagy. Moreover, in vivo studies suggested that βOHB played a protective role by targeting the HCAR2‐AMPK‐PINK1 axis. In conclusion, βOHB enhanced chondrocyte mitophagy through the HCAR2/AMPK/PINK1/Parkin pathway, offering a potential therapeutic approach for the treatment of OA. [ABSTRACT FROM AUTHOR]

Self and nonself discrimination is fundamental to immunity. However, it remains largely enigmatic how the mechanisms of distinguishing nonself from self originated. As an intracellular nucleic acid sensor, protein kinase R (PKR) recognizes double-stranded RNA (dsRNA) and represents a crucial component of antiviral innate immunity. Here, we combine phylogenomic and functional analyses to show that PKR proteins probably originated from a preexisting kinase protein through acquiring dsRNA binding domains at least before the last common ancestor of jawed vertebrates during or before the Silurian period. The function of PKR appears to be conserved across jawed vertebrates. Moreover, we repurpose a protein closely related to PKR proteins into a putative dsRNA sensor, recapturing the making of PKR. Our study illustrates how a nucleic acid sensor might have originated via molecular tinkering with preexisting proteins and provides insights into the origins of innate immunity. [ABSTRACT FROM AUTHOR]

Introduction: Research on Glycyrrhiza uralensis, a nonhalophyte that thrives in saline-alkaline soil and a traditional Chinese medicinal component, is focused on improving its ability to tolerate salt stress to increase its productivity and preserve its "Dao-di" characteristics. Furthermore, the inoculation of bioagents such as Bacillus subtilis to increase plant responses to abiotic stressors is currently a mainstream strategy. Mitogen-activated protein kinase (MAPK), a highly conserved protein kinase, plays a significant role in plant responses to various abiotic stress pathways. Methods: This investigation involved the identification of 21 members of the GuMAPK family from the genome of G. uralensis, with an analysis of their protein conserved domains, gene structures, evolutionary relationships, and phosphorylation sites using bioinformatics tools. Results: Systematic evolutionary analysis of the 21 GuMAPKs classified them into four distinct subgroups, revealing significant differences in gene structure and exon numbers. Collinearity analysis highlighted the crucial role of segmental duplication in expanding the GuMAPK gene family, which is particularly evident in G. uralensis and shows a close phylogenetic relationship with Arabidopsis thaliana, tomato, and cucumber. Additionally, the identification of phosphorylation sites suggests a strong correlation between GuMAPK and various physiological processes, including hormonal responses, stress resistance, and growth and development. Protein interaction analysis further supported the role of GuMAPK proteins in regulating essential downstream genes. Through examination of transcriptome expression patterns, GuMAPK16-2 emerged as a prospective pivotal regulatory factor in the context of salt stress and B. subtilis inoculation, a finding supported by its subcellular localization within the nucleus. Discussion: These discoveries offer compelling evidence for the involvement of GuMAPK in the salt stress response and for the exploration of the mechanisms underlying B. subtilis' enhancement of salt tolerance in G. uralensis. [ABSTRACT FROM AUTHOR]

ABSTRACT Salinization poses a significant challenge in agriculture, exacerbated by anthropogenic global warming. Biostimulants, derived from living microorganisms or natural extracts, have emerged as valuable tools for conventional and organic agriculture. However, our understanding of the molecular mechanisms underlying the effects of biostimulants is very limited, especially in crops under real cultivation conditions. In this study, we adopted an integrative approach to investigate the effectiveness of the combined application of plant growth‐promoting bacterium (Bacillus megaterium strain BM08) and a non‐microbial biostimulant under control conditions (normal watering) and salt stress. After confirming the yield increase under both conditions, we investigated the molecular mechanisms underlying the observed effect by measuring a number of physiological parameters (i.e., lipid peroxidation, antioxidants, chlorophylls, total phenolics and phytohormone content), as well as RNA sequencing and primary metabolite analyses. Our findings reveal that the combined effect of the microbial and non‐microbial biostimulants led to a decrease in the antioxidant response and an up‐regulation of genes involved in cytokinin biosynthesis under salt stress conditions. This, in turn, resulted in a higher concentration of the bioactive cytokinin, isopentenyladenosine, in roots and leaves and an increase in γ‐aminobutyric acid, a non‐proteic amino acid related to abiotic stress responses. In addition, we observed a decrease in malic acid, along with an abscisic acid (ABA)‐independent up‐regulation of SR‐kinases, a family of protein kinases associated with abiotic stress responses. Furthermore, we observed that the single application of the non‐microbial biostimulant triggers an ABA‐dependent response under salt stress; however, when combined with the microbial biostimulant, it potentiated the mechanisms triggered by the BM08 bacterial strain. This comprehensive investigation shows that the combination of two biostimulants is able to elicit a cytokinin‐dependent response that may explain the observed yield increase under salt stress conditions. [ABSTRACT FROM AUTHOR]

Mitogen‐activated protein kinase (MAPK) cascade is the center of plant signal transduction system that amplify immune signals into cellular responses by phosphorylating diverse substrates. The MAPK cascade consisting of MAPK kinase kinases (MAPKKKs), MAPK kinases (MAPKKs), and MAPKs is well characterized in plants, in which Raf‐like kinases are generally regarded as MAPKKKs. However, it is rarely reported that Raf‐like MAPKKKs function as middle regulators to link MAPK and its downstream transcription factors in plant immunity. Verticillium wilt, caused by the soil‐borne vascular fungus Verticillium dahliae, is a serious disease in many plants, including cotton. The previous studies showed that GhMPK9 (a MAPK) is involved in the response to Verticillium wilt. Here, the Raf‐like kinase GhRAF39_1 is reported as helper regulates the phosphorylation of WRKY transcription factor GhWRKY40a by GhMPK9. The phosphorylated GhWRKY40a can further activate the transcription of GhERF1b to up‐regulate defense‐related genes while inhibit the transcription of GhABF2 to regulate the stomatal opening, thus improving the resistance to Verticillium wilt in cotton. This study reveals a new signaling module of GhMPK9‐GhRAF39_1‐GhWRKY40a to regulate GhERF1b‐ and GhABF2‐mediated defense responses, which triggers plant defense against Verticillium wilt. [ABSTRACT FROM AUTHOR]

Background: We aimed to gain insight into the response mechanism of alfalfa (Medicago sativa) to drought stress by recognizing and analyzing drought-responsive genes in the roots of different root types of alfalfa. The rhizomatous-rooted M. sativa cv.'Qingshui' (QS), tap-rooted M. sativa cv.'Longdong' (LD), and creeping-rooted M. varia cv. 'Gongnong No. 4' (GN) were used to analyze the transcriptome information and physiological characteristics of the root systems of the cultivars under simulated drought stress using PEG-6000. Results: It was found that aridity caused a significant increase in the content of osmotic stress substances and antioxidant enzyme activity. The content of malondialdehyde (MDA) in QS was lower than that in LD and GN under moisture stress, indicating a stronger accumulation capacity of osmotic regulatory substances. Based on sequencing results, 14,475, 9336, and 9243 upregulated DEGs from QS, LD, and GN were annotated into 26, 29, and 28 transcription factor families, respectively. QS showed more DEGs than LD and GN. KEGG enrichment analysis identified that DEGs were significantly enriched in metabolic pathways such as amino acid biosynthesis, phenylpropanoid biosynthesis, plant hormone signaling transduction, and MAPK pathways. This suggests a strong correlation between these pathways and drought stress. The results also show that genes associated with ABA hormone signaling (MS. gene93372, MS. gene072046, and MS. gene012975) are crucial for plant's adaptation to drought stress. Conclusions: These genes, such as serine/threonine protein kinases and abscisic acid receptors, play a crucial role in plant hormone signaling and MAPK pathways. They could serve as potential candidate genes for drought resistance research in alfalfa, providing a molecular foundation for studying drought resistance. [ABSTRACT FROM AUTHOR]

Aim To investigate whether SIRT6 overexpression inhibits angiotensin Ⅱ (AngⅡ)-induced cardiomyocyte apoptosis by activating adenosine 5′-monophosphate-activated protein kinase / nuclear factor erythroid 2-related factor 2 / heme oxygenase-1(AMPK/ Nrf2 / HO-1) signaling pathway. Methods The experiment was divided into 4 groups: control group, AngⅡ group,AngⅡ+SIRT6 group, AngⅡ+empty vector (EV) group. The mRNA level of SIRT6 was detected by RT-PCR. The cell activity was measured by MTT assay. The cell apoptosis was analyzed by flow cytometry. SIRT6, cardiomyocyte apoptosis related proteins (Bax, cleaved Caspase-3, Bcl-2), DNA damage related proteins (γ-H2AX, p-ATM), AMPK/ Nrf2 / HO-1 signaling pathway related proteins (p-AMPK, Nrf2, HO-1) were measured by Western blot. The reactive oxygen species (ROS) content was determined by DCFH-DA staining. The changes of the above indexes among the groups were observed. Results Compared with control group, the mRNA and protein expression levels of SIRT6 and cell activity were significantly decreased in AngⅡ group. Apoptosis rate, the expressions of Bax, cleaved Caspase-3 were increased, and the expression of Bcl-2 was decreased. The expressions of γ-H2AX and pATM were increased, and the expressions of p-AMPK, Nrf2, HO-1 were decreased. The activity of ROS was increased (P<0. 01). Compared with AngⅡ+EV group, the expression of SIRT6 and cell activity were significantly increased in AngⅡ+SIRT6 group. Apoptosis rate, the expressions of Bax and cleaved Caspase-3 were decreased, and the expression of Bcl-2 was increased. The expressions of γ-H2AX and p-ATM were decreased, the expressions of p-AMPK, Nrf2, HO-1 were increased. The activity of ROS was decreased (P<0. 01). Conclusion SIRT6 overexpression inhibits AngⅡ- induced cardiomyocyte apoptosis through activation of AMPK/ Nrf2 / HO-1 signaling pathway. [ABSTRACT FROM AUTHOR]

In a wheat breeding line XQ-0508 showing consistent resistance to powdery mildew disease, a recessive gene, designated PmXQ-0508, was identified and mapped to a distal region on chromosome arm 2BS. Of three resistance-associated genes in this region, one encoding a protein kinase was selected as the primary candidate for PmXQ-0508. Ten closely linked DNA markers developed in the study could be used for marker-assisted selection for powdery-mildew resistance in breeding programs. [ABSTRACT FROM AUTHOR]

TOR protein kinases serve as the catalytic subunit of the TORC1 and TORC2 complexes, which regulate cellular growth, proliferation, and survival. In the fission yeast, Schizosaccharomyces pombe, cells lacking TORC2 or its downstream kinase Gad8 (AKT or SGK1 in human cells) exhibit sensitivity to a wide range of stress conditions, including DNA damage stress. One of the first responses to DNA damage is the phosphorylation of C-terminal serine residues within histone H2AX in human cells (γH2AX), or histone H2A in yeast cells (γH2A). The kinases responsible for γH2A in S. pombe are the two DNA damage checkpoint kinases Rad3 and Tel1 (ATR and ATM, respectively, in human cells). Here we report that TORC2-Gad8 signaling is required for accumulation of γH2A in response to DNA damage and during quiescence. Using the TOR-specific inhibitor, Torin1, we demonstrate that the effect of TORC2 on γH2A in response to DNA damage is immediate, rather than adaptive. The lack of γH2A is restored by deletion mutations of transcription and chromatin modification factors, including loss of components of Paf1C, SAGA, Mediator, and the bromo-domain proteins Bdf1/Bdf2. Thus, we suggest that TORC2-Gad8 may affect the accumulation of γH2A by regulating chromatin structure and function. [ABSTRACT FROM AUTHOR]

Isoforms of microtubule-associated protein 2 (MAP2) differ from their homolog Tau in the sequence and interactions of the N-terminal region. Binding of the N-terminal region of MAP2c (N-MAP2c) to the dimerization/docking domains of the regulatory subunit RIIa of cAMP-dependent protein kinase (RIIDD2) and to the Src-homology domain 2 (SH2) of growth factor receptor-bound protein 2 (Grb2) have been described long time ago. However, the structural features of the complexes remained unknown due to the disordered nature of MAP2. Here, we provide structural description of the complexes. We have solved solution structure of N-MAP2c in complex with RIIDD2, confirming formation of an amphiphilic α-helix of MAP2c upon binding, defining orientation of the ahelix in the complex and showing that its binding register differs from previous predictions. Using chemical shift mapping, we characterized the binding interface of SH2-Grb2 and rat MAP2c phosphorylated by the tyrosine kinase Fyn in their complex and proposed a model explaining differences between SH2-Grb2 complexes with rat MAP2c and phosphopeptides with a Grb2-specific sequence. The results provide the structural basis of a potential role of MAP2 in regulating cAMP-dependent phosphorylation cascade via interactions with RIIDD2 and Ras signaling pathway via interactions with SH2-Grb2. [ABSTRACT FROM AUTHOR]

In Saccharomyces cerevisiae, Pah1 phosphatidate (PA) phosphatase, which catalyzes the Mg2+-dependent dephosphorylation of PA to produce diacylglycerol, plays a key role in utilizing PA for the synthesis of the neutral lipid triacylglycerol and thereby controlling the PA-derived membrane phospholipids. The enzyme function is controlled by its subcellular location as regulated by phosphorylation and dephosphorylation. Pah1 is initially inactivated in the cytosol through phosphorylation by multiple protein kinases and then activated via its recruitment and dephosphorylation by the protein phosphatase Nem1-Spo7 at the nuclear/endoplasmic reticulum membrane where the PA phosphatase reaction occurs. Many of the protein kinases that phosphorylate Pah1 have yet to be characterized with the identification of the target residues. Here, we established Pah1 as a bona fide substrate of septinassociated Hsl1, a protein kinase involved in mitotic morphogenesis checkpoint signaling. The Hsl1 activity on Pah1 was dependent on reaction time and the amounts of protein kinase, Pah1, and ATP. The Hsl1 phosphorylation of Pah1 occurred on Ser-748 and Ser-773, and the phosphorylated protein exhibited a 5-fold reduction in PA phosphatase catalytic efficiency. Analysis of cells expressing the S748A and S773A mutant forms of Pah1 indicated that Hsl1-mediated phosphorylation of Pah1 promotes membrane phospholipid synthesis at the expense of triacylglycerol, and ensures the dependence of Pah1 function on the Nem1-Spo7 protein phosphatase. This work advances the understanding of how Hsl1 facilitates membrane phospholipid synthesis through the phosphorylation-mediated regulation of Pah1. [ABSTRACT FROM AUTHOR]

The PKC-related kinases (PRKs, also termed PKNs) are important in cell migration, cancer, hepatitis C infection, and nutrient sensing. They belong to a group of protein kinases called AGC kinases that share common features like a C-terminal extension to the catalytic domain comprising a hydrophobic motif. PRKs are regulated by N-terminal domains, a pseudosubstrate sequence, Rho-binding domains, and a C2 domain involved in inhibition and dimerization, while Rho and lipids are activators. We investigated the allosteric regulation of PRK2 and its interaction with its upstream kinase PDK1 using a chemical biology approach. We confirmed the phosphoinositide-dependent protein kinase 1 (PDK1)-interacting fragment (PIF)-mediated docking interaction of PRK2 with PDK1 and showed that this interaction can be modulated allosterically. We showed that the polypeptide PIFtide and a small compound binding to the PIF-pocket of PRK2 were allosteric activators, by displacing the pseudosubstrate PKL region from the active site. In addition, a small compound binding to the PIF-pocket allosterically inhibited the catalytic activity of PRK2. Together, we confirmed the docking interaction and allostery between PRK2 and PDK1 and described an allosteric communication between the PIF-pocket and the active site of PRK2, both modulating the conformation of the ATP-binding site and the pseudosubstrate PKL-binding site. Our study highlights the allosteric modulation of the activity and the conformation of PRK2 in addition to the existence of at least two different complexes between PRK2 and its upstream kinase PDK1. Finally, the study highlights the potential for developing allosteric drugs to modulate PRK2 kinase conformations and catalytic activity. [ABSTRACT FROM AUTHOR]

Protein phosphorylation by kinases regulates mammalian cell functions, such as growth, division, and signal transduction. Among human kinases, NME1 and NME2 are associated with metastatic tumor suppression but remain understudied due to the lack of tools to monitor their cellular substrates. In particular, NME1 and NME2 are multispecificity kinases phosphorylating serine, threonine, histidine, and aspartic acid residues of substrate proteins, and the heat and acid sensitivity of phosphohistidine and phosphoaspartate complicates substrate discovery and validation. To provide new substrate monitoring tools, we established the g-phosphate– modified ATP analog, ATP-biotin, as a cosubstrate for phosphorylbiotinylation of NME1 and NME2 cellular substrates. Building upon this ATP-biotin compatibility, the Kinasecatalyzed Biotinylation with Inactivated Lysates for Discovery of Substrates method enabled validation of a known substrate and the discovery of seven NME1 and three NME2 substrates. Given the paucity of methods to study kinase substrates, ATPbiotin and the Kinase-catalyzed Biotinylation with Inactivated Lysates for Discovery of Substrates method are valuable tools to characterize the roles of NME1 and NME2 in human cell biology. [ABSTRACT FROM AUTHOR]

Melanoma, a cancer arising from melanocytes, requires a novel treatment strategy because of the ineffectiveness of conventional therapies in certain patients. Fustin is a flavanonol found in young fustic (Cotinus coggygria). However, little is known about its antimelanoma effects. Our study demonstrates that fustin suppresses the growth of B16 melanoma cells. Phalloidin staining of cytoskeletal actin revealed that fustin induced a conformational change in the actin structure of melanoma cells, accompanied by suppressed phosphorylation of myosin regulatory light chain 2 (MLC2), a regulator of actin structure. Furthermore, the protein kinase A (cAMP-dependent protein kinase) inhibitor H89 completely attenuated fustin-induced downregulation of phosphorylated myosin phosphatase targeting subunit 1, which is involved in dephosphorylation of MLC2. In a mouse model, administration of fustin suppressed tumor growth in B16 melanoma cells without adverse effects. In conclusion, our findings suggest that fustin effectively suppresses melanoma cell growth both in vitro and in vivo. [ABSTRACT FROM AUTHOR]

RASopathies represent a distinct class of neurodevelopmental syndromes caused by germline variants in the Ras/MAPK pathways. Recently, a novel disease‐gene association was implicated in MAPK kinase kinase kinase 4 (MAP4K4), which regulates the upstream signals of the MAPK pathways. However, to our knowledge, only two studies have reported the genotype–phenotype relationships in the MAP4K4‐related disorder. This study reports on a Korean boy harboring a novel de novo missense variant in MAP4K4 (NM_001242559:c.569G>T, p.Gly190Val), revealed by trio exome sequencing, and located in the hotspot of the protein kinase domain. The patient exhibited various clinical features, including craniofacial dysmorphism, language delay, congenital heart defects, genitourinary anomalies, and sagittal craniosynostosis. Our study expands the phenotypic association of the MAP4K4‐related disorder to include syndromic craniosynostosis, thereby providing further insights into the role of the RAS/MAPK pathways in the development of premature fusion of calvarial sutures. [ABSTRACT FROM AUTHOR]

The present study assessed the impact of glycyrrhizin on the mechanisms of progression and metastasis in cervical cancer cells. To this end, cell proliferation, migration, and invasion and protein/mRNA expression levels of protein kinase B, glycogen synthase kinase-3 β and β-catenin were measured in three groups of cells: normal cervical epithelial cell line End1/E6E7 (Group A), human cervical squamous cell carcinoma cell line C33a (group B), and human cervical squamous cell carcinoma cell line C33a treated with 50μmol/L glycyrrhizin (Group C). Results showed that glycyrrhizin treatment decreased the proliferation, migration, and invasion of C33a cells and increased apoptosis compared to the cervical cancer control cells. Expression levels of proteins associated with apoptosis such as FS-7-associated surface antigen, Bcl-2-associated X protein and Fas ligand were higher, while protein kinase B pathway activity was attenuated in the glycyrrhizin-treated group compared to the cervical cancer control group. These results suggest that glycyrrhizin may impair cervical cancer cell viability and impede their progression and metastasis by modulating the protein kinase B/glycogen synthase kinase-3β/β-catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides have gradually gained advantages over small molecule inhibitors for their multifunctional effects, synthesising accessibility and target specificity. The current study aims to determine an antimicrobial peptide to inhibit PknB, a serine/threonine protein kinase (STPK), by binding efficiently at the helically oriented hinge region. A library of 5626 antimicrobial peptides from publicly available repositories has been prepared and categorised based on the length. Molecular docking using ADCP helped to find the multiple conformations of the subjected peptides. For each peptide served as input the tool outputs 100 poses of the subjected peptide. To maintain an efficient binding for relatively a longer duration, only those peptides were chosen which were seen to bind constantly to the active site of the receptor protein over all the poses observed. Each peptide had different number of constituent amino acid residues; the peptides were classified based on the length into five groups. In each group the peptide length incremented upto four residues from the initial length form. Five peptides were selected for Molecular Dynamic simulation in Gromacs based on higher binding affinity. Post-dynamic analysis and the frame comparison inferred that neither the shorter nor the longer peptide but an intermediate length of 15 mer peptide bound well to the receptor. Residual substitution to the selected peptides was performed to enhance the targeted interaction. The new complexes considered were further analysed using the Elastic Network Model (ENM) for the functional site's intrinsic dynamic movement to estimate the new peptide's role. The study sheds light on prospects that besides the length of peptides, the combination of constituent residues equally plays a pivotal role in peptide-based inhibitor generation. The study envisages the challenges of fine-tuned peptide recovery and the scope of Machine Learning (ML) and Deep Learning (DL) algorithm development. As the study was primarily meant for generation of therapeutics for Tuberculosis (TB), the peptide proposed by this study demands meticulous invitro analysis prior to clinical applications. [ABSTRACT FROM AUTHOR]

Summary: Shifts in pollinator occurrence and their pollen transport effectiveness drive the evolution of mating systems in flowering plants. Understanding the genomic basis of these changes is essential for predicting the persistence of a species under environmental changes. We investigated the genomic changes in Brassica rapa over nine generations of pollination by hoverflies associated with rapid morphological evolution toward the selfing syndrome.We combined a genotyping‐by‐sequencing (GBS) approach with a genome‐wide association study (GWAS) to identify candidate genes, and assessed their functional role in the observed morphological changes by studying mutations of orthologous genes in the model plant Arabidopsis thaliana.We found 31 candidate genes involved in a wide range of functions from DNA/RNA binding to transport. Our functional assessment of orthologous genes in A. thaliana revealed that two of the identified genes in B. rapa are involved in regulating the size of floral organs. We found a protein kinase superfamily protein involved in petal width, an important trait in plant attractiveness to pollinators. Moreover, we found a histone lysine methyltransferase (HKMT) associated with stamen length.Altogether, our study shows that hoverfly pollination leads to rapid evolution toward the selfing syndrome mediated by polygenic changes. [ABSTRACT FROM AUTHOR]

Cold stress negatively impacts the growth, development, and quality of Camellia sinensis (Cs, tea) plants. CBL‐interacting protein kinases (CIPK) comprise a pivotal protein family involved in plant development and response to multiple environmental stimuli. However, their roles and regulatory mechanisms in tea plants (Camellia sinensis (L.) O. Kuntze) remain unknown. Here we show that CsCBL‐interacting protein kinase 11 (CsCIPK11), whose transcript abundance was significantly induced at low temperatures, interacts and phosphorylates tau class glutathione S‐transferase 23 (CsGSTU23). CsGSTU23 was also a cold‐inducible gene and has significantly higher transcript abundance in cold‐resistant accessions than in cold‐susceptible accessions. CsCIPK11 phosphorylated CsGSTU23 at Ser37, enhancing its stability and enzymatic activity. Overexpression of CsCIPK11 in Arabidopsis thaliana resulted in enhanced cold tolerance under freezing conditions, while transient knockdown of CsCIPK11 expression in tea plants had the opposite effect, resulting in decreased cold tolerance and suppression of the C‐repeat‐binding transcription factor (CBF) transcriptional pathway under freezing stress. Furthermore, the transient overexpression of CsGSTU23 in tea plants increased cold tolerance. These findings demonstrate that CsCIPK11 plays a central role in the signaling pathway to cold signals and modulates antioxidant capacity by phosphorylating CsGSTU23, leading to improved cold tolerance in tea plants. [ABSTRACT FROM AUTHOR]

Background: Deoxyribonuclease 2 (DNase II) plays a key role in clearing cytoplasmic double-stranded DNA (dsDNA). Deficiency of DNase II leads to DNA accumulation in the cytoplasm. Persistent dsDNA in neurons is an early pathological hallmark of senescence and neurodegenerative diseases including Alzheimer's disease (AD). However, it is not clear how DNase II and neuronal cytoplasmic dsDNA influence neuropathogenesis. Tau hyperphosphorylation is a key factor for the pathogenesis of AD. The effect of DNase II and neuronal cytoplasmic dsDNA on neuronal tau hyperphosphorylation remains unclarified. Methods: The levels of neuronal DNase II and dsDNA in WT and Tau-P301S mice of different ages were measured by immunohistochemistry and immunolabeling, and the levels of DNase II in the plasma of AD patients were measured by ELISA. To investigate the impact of DNase II on tauopathy, the levels of phosphorylated tau, phosphokinase, phosphatase, synaptic proteins, gliosis and proinflammatory cytokines in the brains of neuronal DNase II-deficient WT mice, neuronal DNase II-deficient Tau-P301S mice and neuronal DNase II-overexpressing Tau-P301S mice were evaluated by immunolabeling, immunoblotting or ELISA. Cognitive performance was determined using the Morris water maze test, Y-maze test, novel object recognition test and open field test. Results: The levels of DNase II were significantly decreased in the brains and the plasma of AD patients. DNase II also decreased age-dependently in the neurons of WT and Tau-P301S mice, along with increased dsDNA accumulation in the cytoplasm. The DNA accumulation induced by neuronal DNase II deficiency drove tau phosphorylation by upregulating cyclin-dependent-like kinase-5 (CDK5) and calcium/calmodulin activated protein kinase II (CaMKII) and downregulating phosphatase protein phosphatase 2A (PP2A). Moreover, DNase II knockdown induced and significantly exacerbated neuron loss, neuroinflammation and cognitive deficits in WT and Tau-P301S mice, respectively, while overexpression of neuronal DNase II exhibited therapeutic benefits. Conclusions: DNase II deficiency and cytoplasmic dsDNA accumulation can initiate tau phosphorylation, suggesting DNase II as a potential therapeutic target for tau-associated disorders. Scheme depicting the possible mechanism by which DNase II deficiency induces cognitive impairment in mice. DNase II deficiency induces tau phosphorylation by regulating kinases CDK5 and CaMKII as well as phosphatase PP2A through accumulation of undigested damaged DNA in the cytoplasm of neurons. Then phosphorylated tau induces synaptic loss, neuroinflammation, and neuronal apoptosis, eventually rendering cognitive impairment in mice. [ABSTRACT FROM AUTHOR]

Background and aims: PKC‐fused blue naevi are a recently described group of melanocytic tumours that have distinctive morphological features, including a pigmented epithelioid melanocytoma‐like junctional component or a dermal biphasic architecture associating with naevocytoid nests surrounded by dendritic and spindled pigmented melanocytes (so‐called 'combined common and blue naevus'). There have been reports of smooth muscle hyperplasia in a hamartoma‐like pattern in cases of combined blue naevi without genetic exploration. Materials and methods: Herein, we describe 12 cases of protein kinase C (PKC)‐fused blue tumours associated with a co‐existing smooth muscle hyperplasia, identified from a total of 98 PKC‐fused melanocytic tumours. Archived slides of PKC‐fused blue naevi with haematoxylin, eosin and phloxin staining, immunohistochemistry and molecular confirmation of a PKC‐fusion by fluorescence in‐situ hybridisation (FISH) or RNAseq were re‐evaluated for identification of notable smooth muscle hyperplasia. Fifty‐one of these slides had already been studied in a previous publication from our group. Results: The hyperplasia ranged from hypertrophic arrector pili muscles to extensive horizontal bundles of disorganised fibres constantly associated and limited within a biphasic dermal melanocytic component. At least one arrector pili muscle was always visible within the tumour, with occasionally direct extension of the hyperplastic fibres from the main muscle body. These muscle fibres were devoid of a PKC‐fusion signal by FISH. PKC molecules are involved in the regulation of smooth muscle function, offering an explanatory framework. Conclusions: These data suggest incorporating smooth muscle hyperplasia as a diagnostic morphological feature of PKC‐fused blue melanocytic tumours. [ABSTRACT FROM AUTHOR]

The polar auxin transport is required for proper plant growth and development. D6 PROTEIN KINASE (D6PK) is required for the phosphorylation of PIN‐FORMED (PIN) auxin efflux carriers to regulate auxin transport, while the regulation of D6PK stabilization is still poorly understood. Here, we found that Cytosolic ABA Receptor Kinases (CARKs) redundantly interact with D6PK, and the interactions are dependent on CARKs' kinase activities. Similarly, CARK3 also could interact with paralogs of D6PK, including D6PKL1, D6PKL2, and D6PKL3. The genetic analysis shows that D6PK acts the downstream of CARKs to regulate Arabidopsis growth, including hypocotyl, leaf area, vein formation, and the length of silique. Loss‐of‐function of CARK3 in overexpressing GFP‐D6PK plants leads to reduce the level of D6PK protein, thereby rescues plant growth. In addition, the cell‐free degradation assays indicate that D6PK is degraded through 26 S proteasome pathway, while the phosphorylation by CARK3 represses this process in cells. In summary, D6PK stabilization by the CARK family is required for auxin‐mediated plant growth and development. Summary statement: The AGC VIII kinase D6 PROTEIN KINASE (D6PK) phosphorylates PIN‐FORMED (PIN) auxin efflux carriers, which is essential for auxin transport in plant cells. This study uncovers a new mechanism for D6PK stability through Cytosolic ABA Receptor Kinases‐mediated phosphorylation to regulate auxin‐controlled Arabidopsis growth and development. [ABSTRACT FROM AUTHOR]

Obesity is one of the more complicated diseases, it can induce numerous life‐threatening diseases mainly diabetes mellitus, cardiovascular disease, hypertension, and certain cancers. In this study, we assessed the efficacy of bacoside‐A (a dammarane‐type triterpenoid saponin derived from the plant Bacopa monniera Linn.) on the adipogenesis of 3T3‐L1 preadipocytes. Results of this study illustrated that bacoside‐A decreased the differentiation of 3T3‐L1 cell, as evidenced by diminution of lipid droplets, which contains triglycerides and other lipids. During the differentiation process, transcription factors, which are mainly participating in adipogenesis such us CCAAT/enhancer‐binding protein α (C/EBPα) and C/EBPβ, peroxisome proliferator‐activated receptor‐γ (PPARγ), and sterol regulatory element‐binding protein‐1c (SREBP‐1c), expressions were significantly suppressed by bacoside‐A. In addition, bacoside‐A showed a potent reduction in genes precise to adipocytes such as lipoprotein lipase (LPL), fatty acid synthase (FAS), adipocyte fatty acid‐binding protein (FABP4), and leptin expressions. Further, bacoside‐A stimulated the phosphorylation of acetyl CoA carboxylase (ACC) and AMP‐activated protein kinase (AMPK). These results demonstrated that bacoside‐A has anti‐adipogenic effects by regulating the transcription factors involved in adipocyte differentiation. Therefore, bacoside‐A might be considered as a potent therapeutic agent for alleviating obesity and hyperlipidemia. [ABSTRACT FROM AUTHOR]

Drought stress is a critical environmental factor that significantly impacts plant growth and productivity. However, the transcriptome analysis of differentially expressed genes in response to drought stress in Camellia oleifera Abel. is still unclear. This study analyzed the transcriptome sequencing data of C. oleifera under drought treatments. A total of 20,674 differentially expressed genes (DEGs) were identified under drought stress, with the number of DEGs increasing with the duration of drought. Specifically, 11,793 and 18,046 DEGs were detected after 8 and 15 days of drought treatment, respectively, including numerous upregulated and downregulated genes. Gene Ontology (GO) enrichment analysis showed that the DEGs were primarily involved in various biological processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that carbon metabolism, glyoxylate and dicarboxylate metabolism, proteasome, glycine, serine, and threonine metabolism were the main affected pathways. Among the DEGs, 376 protein kinases, 42 proteases, 168 transcription factor (TF) genes, and 152 other potential functional genes were identified, which may play significant roles in the drought response of C. oleifera. The expression of relevant functional genes was further validated using quantitative real-time PCR (qRT-PCR). These findings contribute to the comprehension of drought tolerance mechanisms in C. oleifera and bolster the identification of drought-resistant genes for molecular breeding purposes. [ABSTRACT FROM AUTHOR]

Inflammation and aberrant cellular metabolism are widely recognized as hallmarks of cancer. In pancreatic ductal adenocarcinoma (PDAC), inflammatory signaling and metabolic reprogramming are tightly interwoven, playing pivotal roles in the pathogenesis and progression of the disease. However, the regulatory functions of inflammatory mediators in metabolic reprogramming in pancreatic cancer have not been fully explored. Earlier, we demonstrated that pro-inflammatory mediator macrophage migration inhibitory factor (MIF) enhances disease progression by inhibiting its downstream transcriptional factor nuclear receptor subfamily 3 group C member 2 (NR3C2). Here, we provide evidence that MIF and NR3C2 interactively regulate metabolic reprogramming, resulting in MIF-induced cancer growth and progression in PDAC. MIF positively correlates with the HK1 (hexokinase 1), HK2 (hexokinase 2) and LDHA (lactate dehydrogenase) expression and increased pyruvate and lactate production in PDAC patients. Additionally, MIF augments glucose uptake and lactate efflux by upregulating HK1, HK2 and LDHA expression in pancreatic cancer cells in vitro and in mouse models of PDAC. Conversely, a reduction in HK1, HK2 and LDHA expression is observed in tumors with high NR3C2 expression in PDAC patients. NR3C2 suppresses HK1, HK2 and LDHA expression, thereby inhibiting glucose uptake and lactate efflux in pancreatic cancer. Mechanistically, MIF-mediated regulation of glycolytic metabolism involves the activation of the mitogen-activated protein kinase–ERK signaling pathway, whereas NR3C2 interacts with the activator protein 1 to regulate glycolysis. Our findings reveal an interactive role of the MIF/NR3C2 axis in regulating glucose metabolism supporting tumor growth and progression and may be a potential target for designing novel approaches for improving disease outcome. [ABSTRACT FROM AUTHOR]