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Sen, N.

Publications and source records attributed to Sen, N..

18 recordsLinked to original sources

ABCP_finder: A Transformer Embedding-Based Prediction of Anti-Breast Cancer Peptides

Breast cancer remains one of the leading causes of cancer-related deaths among women worldwide. Drug resistance, toxicity, and limited target specificity are the major challenges in the development of effective therapeutics. Anti-breast cancer peptides (ABCPs) have emerged as effective drug candidate due to its low toxicity, high selectivity, and ability to target cancer. However, it is very time consuming and expensive to identify novel ABCPs only through experiment methods. To address this challenge, we developed ABCP_finder, the first dedicated computational framework specifically designed for the prediction of ABCPs using transformer-based protein language model embeddings. Positive and negative datasets were carefully constructed to ensure a biologically meaningful classification task. To prevent the data leakage and realistic evaluation, homology aware train-test split strategy was utilized by using CD-HIT at 30% sequence identity with 80% coverage. Peptide representations were generated using pretrained transformer models, ProtBERT and ESM2, followed by classification using a multilayer perceptron (MLP). Among the tested models, ProtBERT showed superior performance, achieving 93.82% accuracy, 86.88% recall, 90.59% F1-score, 0.8618 MCC, 96.67% AUC, and a Brier Score of 0.0633, demonstrating strong predictive capability under imbalanced conditions. Calibration analysis supported the selection of a 0.7 probability threshold for identifying high confidence ABCPs. Further external validation using xDeep-AcPEP demonstrated that unknown peptide sequences that has been predicted as ABCPs by ABCP_finder are exhibiting favourable IC values. This supports the biological relevance of these unknown peptides. Overall, ABCP_finder provides a reliable and practical platform for large-scale ABCP screening and can significantly accelerate the discovery of novel peptide therapeutics for breast cancer treatment.

bioinformatics↗

Tyrosine phosphorylation and dimerization cooperatively activate NAMPT to enable NAD+ synthesis in cancer

Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD salvage pathway, is frequently upregulated in cancer, yet mechanisms regulating its catalytic activity remain undefined. We identify NAMPT as a direct substrate of multiple proto-oncogenic tyrosine kinases, including ALK, insulin receptor, IGF1R, and PDGFRA. Phosphoproteomics identified NAMPT Y188 as the major phosphorylation site, including the oncogenic fusion kinase NPM1::ALK. NAMPT interacted with NPM1::ALK in the cytoplasm, nucleus, and mitochondria, while Y188 phosphorylation enhanced catalytic activity, NMN/NAD biosynthesis, and downstream metabolism. Conversely, the Y188F mutant reduced enzymatic activity, proliferation, and clonogenicity, whereas disrupting dimerization similarly impaired phosphorylation and function. Interactome analyses showed phosphorylation and dimerization cooperatively remodel NAMPT-associated networks, enriching phosphorylated dimers for metabolic/redox regulators and monomeric NAMPT for ribosome biogenesis. NAMPT inhibition suppressed the growth of both ALK inhibitor-sensitive and -resistant lymphoma cells and enhanced the efficacy of ALK inhibition, revealing kinase-dependent NAMPT activation as a metabolic vulnerability in oncogene-driven cancers.

cancer biology↗

Atonosomes, compartments involved in membrane tension decrease

To ensure survival, cells need to buffer the effects of environmental stress on their plasma membrane, yet the structural mechanisms by which this is acutely achieved remain largely unknown. Here, we propose atonosomes as a unifying identity for a class of previously observed but enigmatic, tension-responsive, plasma membrane-derived compartments that arise across contexts of acute and chronic membrane tension loss. Leveraging unprecedented high resolution cryo-FIB-ET imaging in yeast, we show that atonosomes are complex, organelle-containing structures bounded by membranes and cell wall material, spanning hundreds of nanometers, and displaying a remarkable morphological diversity. Atonosomes form within seconds in response to reduced plasma membrane tension, and their emergence appears to require no dedicated molecular machinery, arising instead as a direct consequence of membrane biophysics. Upon formation, they recruit key membrane-associated proteins, including TORC2, Slm1, and septins. Under conditions of chronic disruption of PM homeostasis, atonosomes become constitutively present. Their stability and reversibility are further modulated by the cell wall, whose polymerization state influences atonosome dynamics. Structural conservation in fungi and ichthyosporea, demonstrates that atonosomes are a conserved stress-triggered response of cell-wall enclosed organisms. Together, these findings establish atonosomes as a novel compartment that mediates cellular responses to plasma membrane tension variation, coupling membrane remodeling and lipid homeostasis to preserve cellular integrity under stress.

cell biology↗

Targeting CD73-A2aR-Mediated Adenosine Signaling at the Tumor-Immune Interface Overcomes Radioresistance

BackgroundRadiotherapy efficacy is constrained by an immunosuppressive tumor microenvironment (TME) enriched in extracellular adenosine and suppressive myeloid populations that attenuate cytotoxic T-cell responses. The CD73-adenosine-A2a/A2b receptor axis represents a key metabolic immune checkpoint; however, the relative contributions of tumor cell-intrinsic versus host-derived adenosine signaling to radiotherapy response remain incompletely defined. MethodsUsing orthotopic murine breast carcinoma models, we interrogated radiation-induced adenosine dynamics and downstream immune remodeling through quantitative adenosine measurements, bulk RNA sequencing, and multiparameter flow cytometry. Genetically engineered models were employed to dissect the roles of tumor-derived CD73 and host A2a/A2b receptors in regulating radiosensitivity. Therapeutic studies evaluated combinatorial targeting of CD73 and A2a/A2b receptors with radiotherapy and anti-PD-1, followed by comprehensive immune profiling in breast carcinomas. ResultsTumor cell-intrinsic CD73 and host A2A receptor signaling cooperatively drive radioresistance and tumor progression. Radiotherapy induces a rapid surge in intratumoral adenosine, triggering transcriptional and cellular programs consistent with myeloid-mediated immunosuppression and lymphocyte dysfunction. Although T-cell infiltration increases at later time point post-irradiation, effector function remains constrained. Pharmacologic inhibition of CD73 and A2a/A2b receptors partially restores T-cell functionality but is insufficient for durable tumor control as monotherapy. In contrast, concurrent blockade of adenosine signaling during radiotherapy, followed by adjuvant PD-1 inhibition, amplifies adaptive antitumor immunity and significantly enhances tumor control. ConclusionsThese findings define a mechanistic link between radiation-induced adenosine signaling and immune dysfunction in the TME. Targeting the CD73-A2a/A2b axis in combination with radiotherapy and checkpoint blockade represents a rational strategy to overcome radioresistance and improve antitumor immunity. STATEMENT OF SIGNIFICANCEThe tumor and immune cell contributions to adenosine signaling play a central role in shaping the therapeutic outcomes of tumor irradiation. Therapeutic targeting of the adenosine signaling axis improves radiosensitivity and efficacy of checkpoint blockade.

cancer biology↗

Systematic prediction and functional analysis of amino acid residues determining product specificity in the plant oxidosqualene cyclase superfamily

Oxidosqualene cyclases (OSCs) catalyse one of natures most intricate enzyme reactions, converting the linear precursor 2,3-oxidosqualene into an array of cyclic triterpene scaffolds through sequential carbocation cascades. Predicting OSC function based on sequence is challenging beyond broad family-level classification. Here, we develop a structure-based computational framework to identify amino acid determinants of OSC product specificity. Using 169 functionally characterised OSCs, we deploy a multifaceted approach combining differential conservation along with structural information, physico-chemical properties of amino acids and binding pocket electrostatics in order to understand the determinants of product specificity. Using Arabidopsis thaliana cycloartenol synthase AtCAS as a model, we then validate our predictions through targeted mutagenesis, achieving stepwise reprogramming towards the protosteryl-type products cucurbitadienol and lanosterol, including complete product switches. Molecular dynamics simulations support a mechanism in which subtle pocket remodelling alters active-site volume, water access and proton-elimination chemistry. These findings provide a blueprint for OSC engineering.

plant biology↗

Light-induced conformational switching and magnetic sensitivity of Drosophila cryptochrome

Cryptochromes are flavoproteins with a number of established and proposed biological functions based on their sensitivity to light. Amongst the latter is the possibility that cryptochromes mediate the geomagnetic compass sense used by migratory birds as a navigational cue. This hypothesis rests on a magnetically sensitive photochemical reaction of the flavin chromophore in which a series of electron transfers within the protein scaffold ultimately generates a signal propagated within the central nervous system of the animal. Although there is a good understanding of the photochemistry and the electron transfer pathway, the protein-mediated mechanisms of signal transduction are still unclear. Here we have examined the response of Drosophila melanogaster cryptochrome - DmCRY, an archetypal cryptochrome - to photochemical activation by means of molecular dynamics simulations, hydrogen-deuterium exchange mass spectrometry, and cavity ring-down spectroscopy. We were able to measure the dynamics of DmCRY at near-residue level resolution, revealing a reversible, long-lived, blue-light induced conformational change in the C-terminal tail of the protein. This putative signalling state was validated using different illumination conditions, and by examining DmCRY variants in which the electron transfer chain was disrupted by point mutation. Our results show how the photochemical behaviour of the flavin chromophore generates a state of DmCRY that may act as a key primer for modulating downstream interactions.

biophysics↗

Mitochondrial ACSS1 regulates the oncometabolite 2-hydroxyglutarate and De Novo Pyrimidine biosynthesis under nutrient-deprived conditions in lymphoma

The mitochondrial Acetyl-CoA synthetase short-chain family member 1 (ACSS1) converts acetate, an energy source in nutrient-deprived conditions, to mitochondrial acetyl-CoA. However, the specific mechanism behind this process remains unknown. Here, we show that ACSS1 is overexpressed in patients with mantle cell lymphoma (MCL), diffuse large B cell lymphoma (DLBCL), chronic lymphocytic leukemia (CLL), and Ibrutinib (IBR)-resistant cell lines. The mitochondrial stress test showed reduced oxygen consumption in ACSS1 knockdown (KD) cell lines. 13C-acetate stable isotope tracing revealed that ACSS1 knockdown (KD) in MCL cell lines attenuates the flux of mitochondrial acetate to acetyl-CoA, acetylcarnitine, and TCA cycle intermediates, including glutamine and aspartate, which are precursors for de novo pyrimidine synthesis. Consistently, there was a decrease in the labeling of glutamate, aspartate, dihydroorotate, and orotate pools in KD cell lines. Pathway analysis revealed the enrichment of de novo pyrimidine synthesis metabolites and depleting ACSS1 impaired cell growth and potential vulnerability of IBR-resistant MCL cells. Further, we discovered that acetate is used to synthesize 2-hydroxyglutarate in an ACSS1-dependent manner, and it is involved in histone methylation. These results highlight a metabolic phenotype in MCL cells, showing their ability to metabolize acetate in nutrient-deprived conditions and provide new insights into the role of ACSS1 in cancer metabolism. SignificanceThe enzyme ACSS1 catalyzes the conversion of acetate, an energy source in nutrient-deprived conditions, to mitochondrial acetyl-CoA. Our results show that ACSS1 may affect cancer metabolism, particularly in MCL. Studies using MCL cell lines showed that reducing ACSS1 activity affects acetate utilization for various metabolic pathways and influences the production of oncometabolite D-2-hydroxyglutarate. Additionally, reducing ACSS1 activity affects the expression of cyclin D1 and inhibits cell growth, highlighting the potential significance of ACSS1 in cancer metabolism.

cancer biology↗

Cardiac stress leads to regulation of Filamin C dimerisation via an ancient phosphorylation-modulated interaction with HSPB7

The biomechanical properties and responses of tissues underpin a variety of physiological functions and pathologies. In striated muscle, the actin-binding protein filamin C (FLNC) is a key protein whose variants causative for a wide range of cardiomyopathies and musculoskeletal pathologies. Seemingly a multi-functional protein that interacts with a variety of partners, how FLNC is regulated at the molecular level is not well understood. Here we have investigated its interaction with HSPB7, a cardiac-specific molecular chaperone whose absence is embryonically lethal. We found that FLNC and HSPB7 interact in cardiac tissue under biomechanical stress, forming a strong hetero-dimer whose structure we have solved by means of X-ray crystallography. Our quantitative analyses show that the hetero-dimer out-competes the FLNC homo-dimer interface, potentially acting to abrogate the ability of the protein to cross-link the actin cytoskeleton, and to enhance its diffusive mobility. We show that phosphorylation of FLNC at threonine 2677, located at the dimer interface and associated with cardiac stress, acts to favour the homo-dimer. Conversely, phosphorylation at tyrosine 2683, also at the dimer interface, has the opposite effect and shifts the equilibrium towards the hetero-dimer. Evolutionary analysis and ancestral sequence reconstruction reveals this interaction and its mechanisms of regulation to date around the time primitive hearts evolved in chordates. Our work rationalises on the molecular level how FLNC might switch between stabilising functions in the cell, and reveals how HSPB7 acts as a specific molecular chaperone that regulates FLNC.

molecular biology↗

Predicting human and viral protein variants affecting COVID-19 susceptibility and repurposing therapeutics

The COVID-19 disease is an ongoing global health concern. Although vaccination provides some protection, people are still susceptible to re-infection. Ostensibly, certain populations or clinical groups may be more vulnerable. Factors causing these differences are unclear and whilst socioeconomic and cultural differences are likely to be important, human genetic factors could influence susceptibility. Experimental studies indicate SARS-CoV-2 uses innate immune suppression as a strategy to speed-up entry and replication into the host cell. Therefore, it is necessary to understand the impact of variants in immunity-associated human proteins on susceptibility to COVID-19. In this work, we analysed missense coding variants in several SARS-CoV-2 proteins and its human protein interactors that could enhance binding affinity to SARS-CoV-2. We curated a dataset of 19 SARS-CoV-2: human protein 3D-complexes, from the experimentally determined structures in the Protein Data Bank and models built using AlphaFold2-multimer, and analysed impact of missense variants occurring in the protein-protein interface region. We analysed 468 missense variants from human proteins and 212 variants from SARS-CoV-2 proteins and computationally predicted their impacts on binding affinities to SARS-CoV-2 proteins, using 3D-complexes. We predicted a total of 26 affinity-enhancing variants from 14 human proteins implicated in increased binding affinity to SARS-CoV-2. These include key-immunity associated genes (TOMM70, ISG15, IFIH1, IFIT2, RPS3, PALS1, NUP98, RAE1, AXL, ARF6, TRIMM, TRIM25) as well as important spike receptors (KREMEN1, AXL and ACE2). We report both common (e.g., Y13N in IFIH1) and rare variants in these proteins and discuss their likely structural and functional impact, using information on known and predicted functional sites. Potential mechanisms associated with immune suppression implicated by these variants are discussed. Occurrence of certain predicted affinity-enhancing variants should be monitored as they could lead to increased susceptibility and reduced immune response to SARS-CoV-2 infection in individuals/populations carrying them. Our analyses aid in understanding the potential impact of genetic variation in immunity-associated proteins on COVID-19 susceptibility and help guide drug-repurposing strategies.

bioinformatics↗

Understanding structural and functional diversity of ATP-PPases using protein domains and functional families in CATH database

ATP-Pyrophosphatases (ATP-PPases) are the most primordial lineage of the large and diverse HUP (HIGH-motif proteins, Universal Stress Proteins, ATP-Pyrophosphatase) superfamily. There are four different ATP-PPase substrate-specificity groups, and members of each group show considerable sequence variation across the domains of life despite sharing the same catalytic function. Over the past decade, there has been a >20-fold expansion in the number of ATP-PPase domain structures most recently from advances in protein structure prediction (e.g. Alphafold2). Using the enriched structural information, we have characterised the two most populated ATP-PPase substrate-specificity groups, the NAD-synthases (NAD) and GMP synthases (GMPS). We performed local structural and sequence comparisons between the NADS and GMPS from different domains of life and identified taxonomic-group specific structural functional motifs. As GMPS and NADS are potential drug targets of pathogenic microorganisms including Mycobacterium tuberculosis, structural motifs specific to bacterial GMPS and NADS provide new insights that may aid antibacterial-drug design.

bioinformatics↗

AlphaFold2 reveals commonalities and novelties in protein structure space for 21 model organisms

Over the last year, there have been substantial improvements in protein structure prediction, particularly in methods like DeepMinds AlphaFold2 (AF2) that exploit deep learning strategies. Here we report a new CATH-Assign protocol which is used to analyse the first tranche of AF2 models predicted for 21 model organisms and discuss insights these models bring on the nature of protein structure space. We analyse good quality models and those with no unusual structural characteristics, i.e., features rarely seen in experimental structures. For the [~]370,000 models that meet these criteria, we observe that 92% can be assigned to evolutionary superfamilies in CATH. The remaining domains cluster into 2,367 putative novel superfamilies. Detailed manual analysis on a subset of 618 of those which had at least one human relative revealed some extremely remote homologies and some further unusual features, but 26 could be confirmed as novel superfamilies and one of these has an alpha-beta propeller architectural arrangement never seen before. By clustering both experimental and predicted AF2 domain structures into distinct global fold groups, we observe that the new AF2 models in CATH increase information on structural diversity by 36%. This expansion in structural diversity will help to reveal associated functional diversity not previously detected. Our novel CATH-Assign protocol scales well and will be able to harness the huge expansion (at least 100 million models) in structural data promised by DeepMind to provide more comprehensive coverage of even the most diverse superfamilies to help rationalise evolutionary changes in their functions.

bioinformatics↗

A structural database of chain-chain and domain-domain interfaces of proteins

In this study, we have mined the PDB and created a structural library of 178,465 interfaces that mediate protein-protein or domain-domain interactions. Interfaces involving the same CATH fold(s) were clustered together. Our analysis of the entries in the library reveals the similarity between chain-chain and domain-domain interactions. The library also illustrates how a single protein fold can interact with multiple folds using similar interfaces. The library is hence a useful resource to study the types of interactions between protein folds. Analyzing the data in the library reveals various interesting aspects of protein-protein and domain-domain interactions such as how proteins belonging to folds that interact with many other folds also have high EC values. These data could be utilized to seek potential binding partners. It can also be utilized to investigate the different ways in which two or more folds interact with one another structurally. We constructed a statistical potential of pair preferences of amino acids across the interface for chain-chain and domain-domain interactions separately. They are quite similar further lending credence to the notion that domain-domain interfaces could be used to study chain-chain interactions. Lastly and importantly, the library includes predicted small molecule binding sites at the protein-protein interfaces. This has applications as interfaces containing small molecule binding sites can be easily targeted to prevent the interaction and perhaps form a part of a therapeutic strategy.

bioinformatics↗

CATHe: Detection of remote homologues for CATH superfamilies using embeddings from protein language models

1.CATH is a protein domain classification resource that combines an automated workflow of structure and sequence comparison alongside expert manual curation to construct a hierarchical classification of evolutionary and structural relationships. The aim of this study was to develop algorithms for detecting remote homologues that might be missed by state-of-the-art HMM-based approaches. The proposed algorithm for this task (CATHe) combines a neural network with sequence representations obtained from protein language models. The employed dataset consisted of remote homologues that had less than 20% sequence identity. The CATHe models trained on 1773 largest, and 50 largest CATH superfamilies had an accuracy of 85.6+-0.4, and 98.15+-0.30 respectively. To examine whether CATHe was able to detect more remote homologues than HMM-based approaches, we employed a dataset consisting of protein regions that had annotations in Pfam, but not in CATH. For this experiment, we used highly reliable CATHe predictions (expected error rate <0.5%), which provided CATH annotations for 4.62 million Pfam domains. For a subset of these domains from homo sapiens, we structurally validated 90.86% of the predictions by comparing their corresponding AlphaFold structures with experimental structures from the CATHe predicted superfamilies.

bioinformatics↗

Characterizing disease-associated human proteins without available protein structures or homologues

Mutations in human proteins lead to diseases. The structure of these proteins can help understand the mechanism of such diseases and develop therapeutics against them. With improved deep learning techniques such as RoseTTAFold and AlphaFold, we can predict the structure of proteins even in the absence of structural homologues. We modeled and extracted the domains from 553 disease-associated human proteins without known protein structures or close homologues in the Protein Databank (PDB). We noticed that the model quality was higher and the RMSD lower between AlphaFold and RoseTTAFold models for domains that could be assigned to CATH families as compared to those which could only be assigned to Pfam families of unknown structure or could not be assigned to either. We predicted ligand-binding sites, protein-protein interfaces, conserved residues in these predicted structures. We then explored whether the disease-associated missense mutations were in the proximity of these predicted functional sites, if they destabilized the protein structure based on ddG calculations or if they were predicted to be pathogenic. We could explain 80% of these disease-associated mutations based on proximity to functional sites, structural destabilization or pathogenicity. When compared to polymorphisms a larger percentage of disease associated missense mutations were buried, closer to predicted functional sites, predicted as destabilising and/or pathogenic. Usage of models from the two state-of-the-art techniques provide better confidence in our predictions, and we explain 93 additional mutations based on RoseTTAFold models which could not be explained based solely on AlphaFold models.

bioinformatics↗

SARS-CoV-2 spike protein predicted to form stable complexes with host receptor protein orthologues from mammals, but not fish, birds or reptiles

SARS-CoV-2 has a zoonotic origin and was transmitted to humans via an undetermined intermediate host, leading to infections in humans and other mammals. To enter host cells, the viral spike protein (S-protein) binds to its receptor, ACE2, and is then processed by TMPRSS2. Whilst receptor binding contributes to the viral host range, S-protein:ACE2 complexes from other animals have not been investigated widely. To predict infection risks, we modelled S-protein:ACE2 complexes from 215 vertebrate species, calculated changes in the energy of the complex caused by mutations in each species, relative to human ACE2, and correlated these changes with COVID-19 infection data. We also analysed structural interactions to better understand the key residues contributing to affinity. We predict that mutations are more detrimental in ACE2 than TMPRSS2. Finally, we demonstrate phylogenetically that human SARS-CoV-2 strains have been isolated in animals. Our results suggest that SARS-CoV-2 can infect a broad range of mammals, but few fish, birds or reptiles. Susceptible animals could serve as reservoirs of the virus, necessitating careful ongoing animal management and surveillance.

bioinformatics↗

Selective Translation Complex Profiling Reveals Staged Initiation and Co-translational Assembly of Initiation Factor Complexes

Translational control targeting mainly the initiation phase is central to the regulation of gene expression. Understanding all of its aspects requires substantial technological advancements. Here we modified yeast Translational Complex Profile sequencing (TCP-seq), related to ribosome profiling, and adopted it for mammalian cells. Human TCP-seq, capable of capturing footprints of 40S subunits (40Ses) in addition to 80S ribosomes (80Ses), revealed that mammalian and yeast 40Ses distribute similarly across 5UTRs indicating considerable evolutionary conservation. We further developed a variation called Selective TCP-seq (Sel-TCP-seq) enabling selection for 40Ses and 80Ses associated with an immuno-targeted factor in yeast and human. Sel-TCP-seq demonstrated that eIF2 and eIF3 travel along 5UTRs with scanning 40Ses to successively dissociate upon start codon recognition. Manifesting the Sel-TCP-seq versatility for gene expression studies, we also identified four initiating 48S conformational intermediates, provided novel insights into ATF4 and GCN4 mRNA translational control, and demonstrated co-translational assembly of initiation factor complexes.

molecular biology↗

Temperature-Dependent Regulation of Upstream Open Reading Frame Translation in S. Cerevisiae

BackgroundTranslation of an mRNA in eukaryotes starts at AUG in most cases. Near-cognate codons (NCCs) such as UUG, ACG and AUU are also used as start sites at low levels in S. cerevisiae. Initiation from NCCs or AUGs in the 5-untranslated regions (UTRs) of mRNAs can lead to translation of upstream open reading frames (uORFs) that might regulate expression of the main ORF (mORF). Although there is some circumstantial evidence that the translation of uORFs can be affected by environmental conditions, little is known about how it is affected by changes in growth temperature.\n\nResultsUsing reporter assays, we found that changes in growth temperature can affect translation from NCC start sites in yeast cells, suggesting the possibility that gene expression could be regulated by temperature by altering use of different uORF start codons. Using ribosome profiling, we provide evidence that growth temperature regulates the efficiency of translation of nearly 200 uORFs in S. cerevisiae. Of these uORFs, most that start with an AUG codon have increased translational efficiency at 37 {degrees}C relative to 30 {degrees}C and decreased efficiency at 20 {degrees}C. For translationally regulated uORFs starting with NCCs, we did not observe a general trend for the direction of regulation as a function of temperature, suggesting mRNA-specific features can determine the mode of temperature-dependent regulation. Consistent with this conclusion, the position of the uORFs in the 5-leader relative to the 5-cap and the start codon of the main ORF correlates with the direction of temperature-dependent regulation of uORF translation. We have identified several novel cases in which changes in uORF translation are inversely correlated with changes in the translational efficiency of the downstream main ORF. Our data suggest that translation of these mRNAs is subject to temperature-dependent, uORF-mediated regulation.\n\nConclusionsOverall, our data suggest that alterations in the translation of specific uORFs by temperature can regulate gene expression in S. cerevisiae.

genomics↗

Predicting and Designing therapeutics against the Nipah virus

Though every outbreak of the Nipah Virus has resulted in high mortality rates (>70% in Southeast Asia), there are no licensed drugs against it. In this study we have considered all 9 Nipah proteins as potential therapeutic targets and computationally identified putative peptides (against G, F, and M proteins) and small molecules inhibitors (against F, G, M, N, and P proteins). The computations include extensive homology/ab initio modelling, peptide design and small molecule docking. An important contribution of this study is the increased structural characterization of Nipah proteins by approximately 90% of what is deposited in the PDB. In addition, we have carried out molecular dynamics simulations on all the designed protein-peptide complexes to check for stability and to estimate binding strengths. Details, including atomic coordinates of all the proteins and their ligand bound complexes, can be accessed at http://cospi.iiserpune.ac.in/Nipah. Our strategy was to tackle the development of therapeutics on a proteome wide scale and the lead compounds identified could be attractive starting points for drug development. To this end, we have designed 4 peptide inhibitors and predicted 70 small molecules (13 with high confidence) against 3 and 5 Nipah proteins respectively. To counter the threat of drug resistance, we have analyzed the sequences of the viral strains from different outbreaks, to check whether they would be sensitive to the binding of the proposed inhibitors.\n\nAuthor SummaryNipah virus infections have killed 72-86% of the infected individuals in Bangladesh and India. The infections are spread via bodily secretions of bats, pigs and other infected individuals. Even though, the disease was first detected in the human population in 1998, there are no approved drugs/vaccines against it. In this study, we have tried to model the 3D structures of the Nipah virus proteins. We have then used these models to design/predict small inhibitory molecules that would bind them and prevent their function. We have also analyzed the different strains of the virus to identify conservation patterns of amino acids in the proteins, which in turn informs us of the efficacy of the drugs. The designed/docked compounds as well as the protein models are freely accessible for experimental validation and hypothesis testing.

bioinformatics↗