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Acetylation is one of the key post-translational protein modifications catalysed by the protein lysine acetyltransferases (KATs). KATs catalyse the transfer of acetyl groups to the epsilon-amino groups of lysine residues in histones and non-histone proteins. Because of its wide range of target proteins, KATs regulate many biological processes, and their aberrant activities may underlie several human diseases, including cancer, asthma, Chronic Obstructive Pulmonary Disease (COPD), and neurological disorders. Unlike most of the histone modifying enzymes, such as lysine methyltransferases, KATs do not possess any conserved domain like SET domain of lysine methyltransferases. However, almost all the major families of KATs are found to be transcriptional coactivators or adaptor proteins, with defined catalytic domains, called canonical KATs. Over the past two decades, a few proteins have been discovered to possess intrinsic KAT activity but are not classical coactivators. We would like to categorize them as non-canonical KATs (NC-KATs). These NC-KATs include general transcription factors TAFII250, mammalian TFIIIC complex, and mitochondrial protein GCN5L1, etc. This review focuses on our understanding, as well as controversies regarding non-canonical KATs, where we compare the structural and functional similarities and dissimilarities of non-canonical KATs with the canonical KATs. This review also highlights the potential role of NC-KATs in health and diseases.

Biocatalysis plays an important role in the synthesis of complex organic molecules. Wedelolactone, a natural coumestan, has been reported to have many bioactive properties. A novel and efficient enzyme obtained from sweet potato juice was used for condensation of 4-hydroxycoumarins with catechols to produce wedelolactone and its structurally diverse analogs in moderate to good yields under mild reaction conditions. Hence, this enzymatic approach creates an opportunity to access many coumestan-based compounds that are potential building blocks for the synthesis of pharmaceutically important molecules.

Human Positive Coactivator 4 (PC4) is a multifaceted chromatin protein involved in diverse cellular processes including genome organization, transcription regulation, replication, DNA repair and autophagy. PC4 exists as a phospho-protein in cells which impinges on its acetylation by p300 and thereby affects its transcriptional co-activator functions via double-stranded DNA binding. Despite the inhibitory effects, the abundance of phosphorylated PC4 in cells intrigued us to investigate its role in chromatin functions in a basal state of the cell. We found that casein kinase-II (CKII)-mediated phosphorylation of PC4 is critical for its interaction with linker histone H1. By employing analytical ultracentrifugation and electron microscopy imaging of in vitro reconstituted nucleosomal array, we observed that phospho-mimic (PM) PC4 displays a superior chromatin condensation potential in conjunction with linker histone H1. ATAC-sequencing further unveiled the role of PC4 phosphorylation to be critical in inducing chromatin compaction of a wide array of coding and non-coding genes in vivo. Concordantly, phospho-PC4 mediated changes in chromatin accessibility led to gene repression and affected global histone modifications. We propose that the abundance of PC4 in its phosphorylated state contributes to genome compaction contrary to its co-activator function in driving several cellular processes like gene transcription and autophagy.

Gram-negative intracellular pathogen Vibrio parahaemolyticus manifests its infection through a series of effector proteins released into the host via the type III secretion system. Most of these effector proteins alter signalling pathways of the host to facilitate survival and proliferation of bacteria inside host cells. Here, we report V. parahaemolyticus (serotype O3:K6) infection-induced histone deacetylation in host intestinal epithelial cells, particularly deacetylation of H3K9, H3K56, H3K18 and H4K16 residues. We found a putative NAD+-dependent deacetylase, vp1524 (vpCobB) of V. parahaemolyticus, was overexpressed during infection. Biochemical assays revealed that Vp1524 is a functional NAD+-dependent Sir2 family deacetylase in vitro, which was capable of deacetylating acetylated histones. Furthermore, we observed that vp1524 is expressed and localized to the nuclear periphery of the host cells during infection. Consequently, Vp1524 translocated to nuclear compartments of transfected cells, deacetylated histones, specifically causing deacetylation of those residues (K56, K16, K18) associated with V. parahaemolyticus infection. This infection induced deacetylation resulted in transcriptional repression of several host genes involved in epigenetic regulation, immune response, autophagy etc. Thus, our study shows that a V. parahaemolyticus lysine deacetylase Vp1524 is secreted inside the host cells during infection, modulating host gene expression through histone deacetylation.

In vitro bioimaging of HEK293 cells using the green luminescent Sc0.98Er0.02AlO3 compound.

SummaryThe positive coactivator 4 or PC4 is a chromatin-associated protein whose role in gene regulation by wild-type p53 is now well-known. During tumorigenesis, p53 is often mutated resulting in its loss of function. A sub-class of these mutants gain new pro-proliferation properties which occur largely due to the upregulation of many pro-proliferation genes. Little is known about the roles of PC4 in tumor cells bearing mutant p53 genes. In this article, we show that PC4 associates with one of the tumor-associated gain-of-function p53 mutants, R273H. This association drives its recruitment to two promoters, UBE2C, and MDR1, known to be responsible for imparting aggressive growth and resistance to many drugs. A previously reported peptide that disrupts PC4-wild-type p53 interaction also disrupts the PC4-R273Hp53 protein-protein interaction. The introduction of this peptide to tumor cells bearing the R273HTP53 gene resulted in a lowering of MDR1 expression and abrogation of drug resistance. Interestingly, cells bearing another gain-of-function mutant R248W do not show the same type of response, suggesting that the action of PC4 on mutant p53s may differ for different GOF mutants. The results presented here suggest that PC4-R273H interaction may be a promising target for reducing proliferation and tumor drug resistance.

Lysine acetylation is the second most well-studied post-translational modification after phosphorylation. While phosphorylation regulates signaling cascades, one of the most significant roles of acetylation is regulation of chromatin structure. Acetyl-coenzyme A (acetyl-CoA) serves as the acetyl group donor for acetylation reactions mediated by lysine acetyltransferases (KATs). On the other hand, NAD+ serves as the cofactor for lysine deacetylases (KDACs). Both acetyl-CoA and NAD+ are metabolites integral to energy metabolism, and therefore, their metabolic flux can regulate the activity of KATs and KDACs impacting the epigenome. In this chapter, we review our current understanding of how metabolic pathways regulate lysine acetylation in normal and cancer cells.

Autophagy is an intracellular catabolic degradative process in which damaged cellular organelles, unwanted proteins and different cytoplasmic components get recycled to maintain cellular homeostasis or metabolic balance. During autophagy, a double membrane vesicle is formed to engulf these cytosolic materials and fuse to lysosomes wherein the entire cargo degrades to be used again. Because of this unique recycling ability of cells, autophagy is a universal stress response mechanism. Dysregulation of autophagy leads to several diseases, including cancer, neurodegeneration and microbial infection. Thus, autophagy machineries have become targets for therapeutics. This chapter provides an overview of the paradoxical role of autophagy in tumorigenesis in the perspective of metabolism.

The enzyme p300, besides having acetyltransferase activity, can also catalyze other acylation modifications, whose physiological implications are still being investigated. Here, we report that the level of histone butyrylation increases globally as well as locally in the promoters of pro-adipogenic genes during adipogenesis. To delineate the role of p300-catalyzed butyrylation from acetylation in adipogenesis, we identified a semisynthetic derivative (LTK-14A) of garcinol, which specifically inhibited histone butyrylation without affecting acetylation. Treatment of 3T3L1 cells with LTK-14A abolished adipogenesis with downregulation of pro-adipogenic genes along with inhibition of H4K5 butyrylation. Administering LTK-14A to high-fat diet-fed and genetically obese db/db mice led to attenuation/decrease in their weight gain. The reduced obesity could be partially attributed to the inhibition of H4K5 butyrylation in adipocytes and liver. This report therefore not only, for the first time, causally links histone butyrylation with adipogenesis but also presents a probable candidate for anti-obesity therapeutics.

The master epigenetic regulator lysine acetyltransferase (KAT) p300/CBP plays a pivotal role in neuroplasticity and cognitive functions. Recent evidence has shown that in several neurodegenerative diseases, including Alzheimer's disease (AD), the expression level and function of p300/CBP are severely compromised, leading to altered gene expression causing pathological conditions. Here, we show that p300/CBP activation by a small-molecule TTK21, conjugated to carbon nanosphere (CSP) ameliorates Aβ-impaired long-term potentiation (LTP) induced by high-frequency stimulation, theta burst stimulation, and synaptic tagging/capture (STC). This functional rescue was correlated with CSP-TTK21-induced changes in transcription and translation. Mechanistically, we observed that the expression of a large number of synaptic plasticity- and memory-related genes was rescued, presumably by the restoration of p300/CBP mediated acetylation. Collectively, these results suggest that small-molecule activators of p300/CBP could be a potential therapeutic molecule for neurodegenerative diseases like AD.

Nucleophosmin (NPM1) is a multifunctional histone chaperone that can activate acetylation-dependent transcription from chromatin templates in vitro. p300-mediated acetylation of NPM1 has been shown to further enhance its transcription activation potential. Acetylated and total NPM1 pools are increased in oral squamous cell carcinoma. However, the role of NPM1 or its acetylated form (AcNPM1) in transcriptional regulation in cells and oral tumorigenesis is not fully elucidated. Using ChIP-seq analyses, we provide the first genome-wide profile of AcNPM1 and show that AcNPM1 is enriched at transcriptional regulatory elements. AcNPM1 co-occupies marks of active transcription at promoters and DNase I hypersensitive sites at enhancers. In addition, using a high-throughput protein interaction profiling approach, we show that NPM1 interacts with RNA Pol II, general transcription factors, mediator subunits, histone acetyltransferase complexes, and chromatin remodelers. NPM1 histone chaperone activity also contributes to its transcription activation potential. Further, NPM1 depletion leads to decreased AcNPM1 occupancy and reduced expression of genes required for proliferative, migratory and invasive potential of oral cancer cells. NPM1 depletion also abrogates the growth of orthotopic tumors in mice. Collectively, these results establish that AcNPM1 functions as a coactivator during during RNA polymerase II-driven transcription and regulates the expression of genes that promote oral tumorigenesis.

Rare-earth ion-activated oxide phosphors are beneficial to overcome problems like photobleaching, reduced lifetime, and the blinking of organic dyes and quantum dots for bioimaging applications. In this work, we report that the phosphors Rb(Bi

Objective To test efficacy, safety and tolerability of Umifenovir in non-severe COVID-19 adult patients. Methods We carried out randomized, double-blind, placebo-controlled, multicenter, phase III trials involving adult (18-75 years), non-severe COVID19 patients, randomized 1:1 on placebo or Umifenovir (800 mg BID, maximum 14 days) respectively along with standard-of-care. The primary endpoint for Asymptotic-mild patients was time to nasopharyngeal swab RT-PCR test negativity. For Moderate patients, the average change in the ordinal scale from the baseline scores on the eight-point WHO ordinal scale was assessed. Results 132 patients were recruited between 3rd October to 28th April 2021, of which 9 discontinued due to various reasons. In Mild-asymptomatic patients (n=82), we found that 73% patients in the Umifenovir arm were RT-PCR negative, while 40% patients in the placebo arm were negative (P=0.004) on day 5. However, in the moderate group (n=41), the WHO scores for the Umifenovir arm was not statistically significant (P=0.125 on day 3), while it was statistically significant in the Mild-asymptomatic group (P=0.019 on day 5). Conclusion Umifenovir meets the primary and secondary endpoint criteria and exhibits statistically significant efficacy for Mild-asymptomatic patients. It is efficacious, safe and well-tolerated at the tested dosage of 800mg BID, maximum 14 days.

ObjectiveThe master epigenetic enzyme EP300 (p300) besides having lysine acetyltransferase activity can also catalyse other acylation modifications (propionylation, butyrylation, crotonylation etc.), the physiological implications of which are yet to be established fully. We hypothesized that p300 catalysed histone butyrylation may have a causal relationship with adipogenesis and the consequent obesity.MethodsHistone butyrylation pattern was investigated in 3T3L1 cells upon adipogenesis by immunoblotting and chromatin immunoprecipitation experiments. A small molecule modulator that could specifically inhibit p300 catalysed butyrylation without affecting its canonical acetyltransferase activity was screened from a series of compounds and then administered in differentiating 3T3L1 adipocytes as well as high fat diet-induced and genetically obese mice to validate the importance of butyrylation in adipogenesis.ResultsHistone butyrylation was increased upon adipogenesis both globally and locally in the promoters of pro-adipogenic genes along with an upregulation in the expression of acyl CoA generating enzyme Acss2, knockdown of which led to reduced butyrylation. Treatment of differentiating 3T3L1 cells with the p300 specific butyrylation inhibitor LTK-14A led to abrogation of adipogenesis with reduced expression of pro-adipogenic genes and inhibition of H4K5 butyrylation. LTK-14A administration could also attenuate weight gain in both mice models of obesity by preventing adipocyte hypertrophy via H4K5 butyrylation inhibition.ConclusionOur results indicate that p300 catalysed histone butyrylation may have a causal relationship with the process of adipogenesis. Site specific inhibition of butyrylation could lead to adipogenesis repression and hence this epigenetic modification could be targeted for obesity treatment.HighlightsHistone butyrylation has been established as a new epigenetic signature in the context of adipogenesis.To the best of our knowledge, this is the first report of a selective inhibitor of p300 catalysed histone acylation (butyrylation) without affecting its canonical acetyltransferase activity.Specific inhibition of H4K5 butyrylation could be a possible mechanism for inhibiting adipogenesis and hepatic steatosis leading to better control of obesity.LTK-14A class of molecule could be developed as anti-obesity therapeutics.Graphical abstractProposed model for the role of p300-mediated histone butyrylation in adipogenesis:In pre-adipocytes, there exists a basal level of histone acetylation while butyrylation is present to a much lesser extent owing to low stoichiometric levels of butyryl CoA. Induction of adipogenesis causes a simultaneous upregulation of histone acetylation and butyrylation marks leading to increased rate of adipogenesis and concomitant transcriptional activation of pro-adipogeneic genes.Onset of obesity in mice, either due to excess energy intake through high fat diet consumption or increased de novo synthesis of fatty acids due to leptin receptor gene mutation leading to hyperphagic behavior, is accompanied by adipocyte hyperplasia and hypertrophy. Both the organs of adipose tissue and liver were found to have enhanced levels of H4K5 butyrylation during obesity. LTK-14A, a butyrylation specific inhibitor could efficiently prevent the processes of adipogenesis and adipocyte hypertrophy due to inhibition of H4K5 butyrylation in these organs. Thus the compound could attenuate weight gain by selective inhibition of butyrylation without affecting acetylation, thereby highlighting the importance of histone butyrylation in adipogenesis and obesity.

The human transcriptional coactivator PC4 has numerous roles to play in the cell. Other than its transcriptional coactivation function, it facilitates chromatin organization, DNA damage repair, viral DNA replication, etc. Although it was found to be an essential protein in vivo, the importance of this multifunctional protein in the regulation of different cellular pathways has not been investigated in details, particularly in oncogenesis. In this study, PC4 downregulation was observed in a significant proportion of mammary tissues obtained from Breast cancer patient samples as well as in a subset of highly invasive and metastatic Breast cancer patient-derived cell lines. We have identified a miRNA, miR-29a which potentially reduce the expression of PC4 both in RNA and protein level. This miR-29a was found to be indeed overexpressed in a substantial number of Breast cancer patient samples and cell lines as well, suggesting one of the key mechanisms of PC4 downregulation. Stable Knockdown of PC4 in MCF7 cells induced its migratory as well as invasive properties. Furthermore, in an orthotopic breast cancer mice model system; we have shown that reduced expression of PC4 enhances the tumorigenic potential substantially. Absence of PC4 led to the upregulation of several genes involved in Epithelial to Mesenchymal Transition (EMT), indicating the possible mechanism of uniform tumour progression in the orthotropic mice. Collectively these data establish the role of PC4 in tumour suppression.

Aurora kinases are Ser/Thr-directed protein kinases which play pivotal roles in mitosis. Recent evidences highlight the importance of these kinases in multiple biological events including skeletal muscle differentiation. Our earlier study identified the transcription factor POU6F1 (or mPOU) as a novel Aurora kinase (Aurk) A substrate. Here, we report that Aurora kinase A phosphorylates mPOU at Ser197 and inhibit its DNA-binding ability. Delving into mPOU physiology, we find that the phospho-mimic (S197D) mPOU mutant exhibits enhancement, while the wild type or the phospho-deficient mutant shows retardation in C2C12 myoblast differentiation. Interestingly, POU6F1 depletion phenocopies S197D-mPOU overexpression in the differentiation context. Collectively, our results signify mPOU as a negative regulator of skeletal muscle differentiation and strengthen the importance of AurkA in skeletal myogenesis.

TP53 is the most frequently mutated tumor suppressor gene in many cancers, yet biochemical characterization of several of its reported mutations with probable biological significance have not been accomplished enough. Specifically, missense mutations in TP53 can contribute to tumorigenesis through gain-of-function of biochemical and biological properties that stimulate tumor growth. Here, we identified a relatively rare mutation leading to a proline to leucine substitution (P152L) in TP53 at the very end of its DNA-binding domain (DBD) in a sample from an Indian oral cancer patient. Although the P152Lp53 DBD alone bound to DNA, the full-length protein completely lacked binding ability at its cognate DNA motifs. Interestingly, P152Lp53 could efficiently tetramerize, and the mutation had only a limited impact on the structure and stability of full-length p53. Significantly, when we expressed this variant in a TP53-null cell line, it induced cell motility, proliferation, and invasion compared with a vector-only control. Also, enhanced tumorigenic potential was observed when P152Lp53-expressing cells were xenografted into nude mice. Investigating the effects of P152Lp53 expression on cellular pathways, we found that it is associated with up-regulation of several pathways, including cell-cell and cell-extracellular matrix signaling, epidermal growth factor receptor signaling, and Rho-GTPase signaling, commonly active in tumorigenesis and metastasis. Taken together, our findings provide a detailed account of the biochemical and cellular alterations associated with the cancer-associated P152Lp53 variant and establish it as a gain-of-function TP53 variant.

Transcriptional coactivator p300, a critical player in eukaryotic gene regulation, primarily functions as a histone acetyltransferase (HAT). It is also an important player in acetylation of a number of nonhistone proteins, p53 being the most prominent one. Recruitment of p300 to p53 is pivotal in the regulation of p53-dependent genes. Emerging evidence suggests that p300 adopts an active conformation upon binding to the tetrameric p53, resulting in its enhanced acetylation activity. As a modular protein, p300 consists of multiple well-defined domains, where the structured domains are interlinked with unstructured linker regions. A crystal structure of the central domain of p300 encompassing Bromo, RING, PHD, and HAT domains demonstrates a compact module, where the HAT active site stays occluded by the RING domain. However, although p300 has a significant role in mediating the transcriptional activity of p53, only a few structural details on the complex of these two full-length proteins are available. Here, we present a cryo-electron microscopy (cryo-EM) study on the p300-p53 complex. The three-dimensional cryo-EM density map of the p300-p53 complex, when compared to the cryo-EM map of free p300, revealed that substantial change in the relative arrangement of Bromo and HAT domains occurs upon complex formation, which is likely required for exposing HAT active site and subsequent acetyltransferase activity. Our observation correlates well with previous studies showing that the presence of Bromodomain is obligatory for effective acetyltransferase activity of HAT. Thus, our result sheds new light on the mechanism whereby p300, following binding with p53, gets activated.

Coactivator associated arginine methyltransferase 1 (CARM1) has been functionally implicated in maintenance of pluripotency, cellular differentiation and tumorigenesis; where it plays regulatory roles by virtue of its ability to coactivate transcription as well as to modulate protein function as an arginine methyltransferase. Previous studies establish an oncogenic function of CARM1 in the context of colorectal and breast cancer, which correlate to its overexpressed condition. However, the mechanism behind its deregulated expression in the context of cancer has not been addressed before. In the present study we uncover an oncogenic function of CARM1 in the context of oral cancer, where it was found to be overexpressed. We also identify YY1 to be a positive regulator of CARM1 gene promoter, where silencing of YY1 in oral cancer cell line could lead to reduction in expression of CARM1. In this context, YY1 showed concomitant overexpression in oral cancer patient samples compared to adjacent normal tissue. Cell line based experiments as well as xenograft study revealed pro-neoplastic functions of YY1 in oral cancer. Transcriptomics analysis as well as qRT-PCR validation clearly indicated pro-proliferative, pro-angiogenic and pro-metastatic role of YY1 in oral cancer. We also show that YY1 is a substrate of CARM1 mediated arginine methylation, where the latter could coactivate YY1 mediated reporter gene activation in vivo. Taken together, CARM1 and YY1 were found to regulate each other in a positive feedback loop to facilitate oral cancer progression.

The interruption of spinal circuitry following spinal cord injury disrupts neural activity and is followed by a failure to mount an effective regenerative gene expression response resulting in permanent neurological disability. Functional recovery requires the enhancement of axonal and synaptic plasticity of spared as well as injured fibres, which need to sprout and/or regenerate to form new connections. Here we will investigate whether the combined epigenetic stimulation of the regenerative gene expression program with neuronal activity-dependent enhancement of neuroplasticity and guidance can overcome the current inability to promote neurological recovery in severe and chronic spinal cord injury. This will be carried out by delivering the small molecule CBP/p300 activator CSP-TTK21 in combination with environmental enrichment. We will deliver the CBP/p300 activator CSP-TTK21 weekly between week twelve and twenty following a severe transection model of spinal cord injury in the mouse. Data analysis will assess modifications in regenerative signalling, in motor and sensory axon sprouting and regeneration, in synaptic plasticity as well as in neurological sensorimotor recovery. This approach will advance our mechanistic understanding of regenerative failure and provide insight of whether combining growth promoting strategies with enhancement of neural activity is an effective therapeutic strategy in chronic spinal cord injury.

Outcome of infection with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) may depend on the host, virus or the host-virus interaction related factors. Complete SARS-CoV-2 genome was sequenced using Illumina and Nanopore platforms from naso-/oro-pharyngeal ri-bonucleic acid (RNA) specimens from COVID-19 patients of varying severity and outcomes, including patients with mild upper respiratory symptoms (n=35), severe disease admitted to intensive care with respiratory and gastrointestinal symptoms (n=21), fatal COVID-19 outcome (n=17) and asymptomatic (n=42). Of a number of genome variants observed, p.16L>L (Nsp1), p.39C>C (Nsp3), p.57Q>H (ORF3a), p.71Y>Y (Membrane glycoprotein), p.194S>L (Nucleocapsid protein) were observed in similar frequencies in different patient subgroups. However, seventeen other variants were observed only in symptomatic patients with severe and fatal COVID-19. Out of the latter, one was in the 5UTR (g.241C>T), eight were synonymous (p.14V>V and p.92L>L in Nsp1 protein, p.226D>D, p.253V>V, and p.305N>N in Nsp3, p.34G>G and p.79C>C in Nsp10 protein, p.789Y>Y in Spike protein), and eight were non-synonymous (p.106P>S, p.157V>F and p.159A>V in Nsp2, p.1197S>R and p.1198T>K in Nsp3, p.97A>V in RdRp, p.614D>G in Spike protein, p.13P>L in nucleocapsid). These were completely absent in the asymptomatic group. SARS-CoV-2 genome variations have a significant impact on COVID-19 presentation, severity and outcome.

The interruption of spinal circuitry following spinal cord injury (SCI) disrupts neural activity and is followed by a failure to mount an effective regenerative response resulting in permanent neurological disability. Functional recovery requires the enhancement of axonal and synaptic plasticity of spared as well as injured fibres, which need to sprout and/or regenerate to form new connections. Here, we have investigated whether the epigenetic stimulation of the regenerative gene expression program can overcome the current inability to promote neurological recovery in chronic SCI with severe disability. We delivered the CBP/p300 activator CSP-TTK21 or vehicle CSP weekly between week 12 and 22 following a transection model of SCI in mice housed in an enriched environment. Data analysis showed that CSP-TTK21 enhanced classical regenerative signalling in dorsal root ganglia sensory but not cortical motor neurons, stimulated motor and sensory axon growth, sprouting, and synaptic plasticity, but failed to promote neurological sensorimotor recovery. This work provides direct evidence that clinically suitable pharmacological CBP/p300 activation can promote the expression of regeneration-associated genes and axonal growth in a chronic SCI with severe neurological disability.

14-3-3 proteins bind to ligands via phospho-serine containing consensus motifs. However, the molecular mechanisms underlying complex formation and dissociation between 14-3-3 proteins and their ligands remain unclear. We identified two conserved acidic residues in the 14-3-3 peptide-binding pocket (D129 and E136) that potentially regulate complex formation and dissociation. Altering these residues to alanine led to opposing effects on centrosome duplication. D129A inhibited centrosome duplication, whereas E136A stimulated centrosome amplification. These results were due to the differing abilities of these mutant proteins to form a complex with NPM1. Inhibiting complex formation between NPM1 and 14-3-3γ led to an increase in centrosome duplication and over-rode the ability of D129A to inhibit centrosome duplication. We identify a novel role of 14-3-3γ in regulating centrosome licensing and a novel mechanism underlying the formation and dissociation of 14-3-3 ligand complexes dictated by conserved residues in the 14-3-3 family.

Summary Background: SARS-Cov2 has caused millions of deaths worldwide and effective antivirals are not yet available. We evaluated the efficacy, tolerability and safety of Umifenovir, a drug used originally against influenza in Russia and China, in non-severe COVID19 adult patients from India. Method : A double-blind placebo controlled Phase III trial spread over 3 hospitals in Lucknow, India viz. King George’s Medical University, ERAs Lucknow Medical College and Ram Manohar Lohia Institute of Medical Sciences was carried out. RT-PCR confirmed COVID19 patients in the age group from 18-75 yrs. were recruited and further stratified into Mild-asymptomatic and Moderate cases. Exclusions included, pregnant or lactating women, severe patients, those suffering from Acute respiratory distress syndrome (ARDS), sepsis shock, requiring invasive ventilator support, ECMO or shock requiring vasopressor support, severe liver disease, severe renal impairment, comorbid conditions like asthma, diabetes with second-third line medicines as defined in the WHO guidance document. Patients were randomized 1:1 on placebo with standard care of therapy or Umifenovir (800 mg BID, maximum 14 days) with standard care of therapy respectively. Computerized randomization was carried out for each group separately through sequentially numbered, opaque, sealed envelopes (SNOSE) in block sizes of six and was administered independently through clinical-site coordinators and to have sufficient number of Mild-asymptomatic and moderate patients. The primary endpoint for Asymptotic-mild patients was time to nasopharyngeal swab negativity by two RT-PCR tests for SARS COV2 antigens taken 24 hrs apart from the date of randomization. For Moderate patients, the average change in the ordinal scale from the baseline scores from randomization on the eight-point ordinal scale as defined by WHO was calculated as the primary endpoint. This trial is registered with the Clinical Trial Registry of India (CTRI) Number: CTRI/2020/09/027535. Findings: A total of 132 patients were recruited in the trial after screening between 3rd October 2020 to 28th April 2021. Of these, 9 patients withdrew consent/ stopped medication on their own. The remaining 123 patients were almost equally distributed into Asymptomatic (35%), Mild (32%) and Moderate (33%) symptoms groups respectively. No Serious adverse events were noted in any of the patients. Only few minor events like headache, stomach ache and nausea were reported and this also was observed almost equally between the Umifenovir and Standard-of-care arms respectively. In the Primary endpoint corresponding to the Mild-asymptomatic patient group (n=82), we found that 73% patients in the Umifenovir arm were RT-PCR negative on the 5th day (P=0.004), while only 40% patients in the placebo arm were negative. In the moderate group, the WHO scores for the Umifenovir arm corresponded to faster clinical improvement as compared to the Placebo arm (P=0.125 on day 3). In the Mild-asymptomatic group, the clinical improvement assessed by the WHO score on day 5 was statistically significant (P=0.019) in the Umifenovir arm compared to the placebo arm and agrees well with the primary endpoint results. Interpretation: Umifenovir is efficacious for Mild-asymptomatic patients and meets the primary and secondary endpoint criteria of the trial. The drug is safe and well tolerated at a dosage of 800 mg BID, maximum 14 days, in adult patients. It exhibits faster time to cure with median 5 days (95%CI, 5-14) in Umifenovir group and median 7 days (95%CI, 5-14) for the placebo group. In moderate patients, administration of Umifenovir co-relates with faster clinical recovery, albeit with less statistical significance. In future studies, the drug should be evaluated as a prophylactic in high-risk adults, and for efficacy in children and pregnant/lactating women.

Cancer is a perturbation of intricate balance between “cell division” and “cell death.” Normal cells divide up to certain extent or limit which is called “Hayflick” limit and then die to maintain normal body homeostasis. Cancer cells do not obey “Hayflick” limit and proliferate uncontrollably to form a tumor. In a simplistic description, cancer is a deregulated cell division due to changes in the genetic material of a cell. According to WHO, cancer is a commonly used name for a large group of diseases with similar characteristic features. Some other commonly used terms to describe cancer include malignant tumors and neoplasms. The most important characteristic feature of cancer is rapid multiplication of cancerous cells and spreading to different parts of the body is known as metastasis. Metastatic cancer is a leading cause of death among the cancer patients across the world (WHO 2018). Some other major characteristic features of cancer cells include the capability to acquire autonomous growth signals, evasion of growth inhibitory signals, angiogenesis, and unlimited replication.

Tumor suppressor p53 controls cell cycle checkpoints and apoptosis via the transactivation of several genes that are involved in these processes. The functions of p53 are regulated by a wide variety of proteins, which interact with it either directly or indirectly. The multifunctional human transcriptional coactivator PC4 interacts with p53 in vivo and in vitro and regulates its function. Here we report the molecular mechanisms of the PC4-mediated activation of p53 function. PC4 interacts with the DNA binding and C-terminal domains of p53 through its DNA binding domain, which is essential for the stimulation of p53 DNA binding. Remarkably, ligation-mediated circularization assays reveal that PC4 induces significant bending in the DNA double helix. Deletion mutants defective in DNA bending are found to be impaired in activating p53-mediated DNA binding and apoptosis. Furthermore, acetylation of PC4 enhances, while phosphorylation abolishes, its ability to bend DNA, activate p53 DNA binding, and, thereby, regulate p53 functions. In conclusion, PC4 activates p53 recruitment to p53-responsive promoters (Bax and p21) in vivo through its interaction with p53 and by providing bent substrate for p53 recruitment. These results elucidate the general molecular mechanisms of activation of p53 function, mediated by its coactivators.