Biology subjects

Singh, R. K.

Publications and source records attributed to Singh, R. K..

At least 37 records · Page 2Linked to original sources

bioRxiv2023

Muscle-specific MEF2D alpha 2 isoform regulates mice exercise capacity, muscle ketolysis, and systemic ketone body availability in mice

Ketone bodies are an alternate fuel source generated by the liver in response to low carbohydrate availability in neonates and after starvation and exhausting exercise in adulthood. The postnatal alternative splicing generates a highly conserved muscle-specific MEF2D2 protein isoform of the transcription factor MEF2D. Here, we discovered that compared to WT mice, MEF2D2 exon knockout (Eko) mice displayed reduced running capacity and muscle expression of all three ketolytic genes, BDH1, OXCT1, and ACAT1. Consistent with reduced muscle utilization of ketone bodies, MEF2D2 Eko mice also showed increased ketone body levels in a tolerance test, after exercise, and upon feeding a ketogenic diet. Lastly, using mitochondria isolated from skeletal muscle, we showed reduced ketone body utilization and respiration in Eko compared to WT mice. Thus, we identified a new role of MEF2D2 protein isoform in regulating skeletal muscle ketone body oxidation, exercise capacity, and its effect on systemic ketone body levels.

molecular biology↗

bioRxiv2022

Targeting MAPAKAP2(MK2) to combat inflammation by avoiding the differential regulation of anti-inflammatory genes by p38 MAPK inhibitors

p38 mitogen-activated protein kinase (p38 MAPK) plays an important role in the key cellular processes related to inflammation. Several small molecule inhibitors of p38 MAPK therefore have been evaluated for their anti-inflammatory potential and progressed from early discovery to late phase clinical trials. Most of these efforts however have failed due to severe toxicity concerns. Since p38 MAPK has several downstream substrates, inhibition of p38 MAPK, therefore, leads to the modulation of all its substrates, resulting into a dis-balance of pro- and anti-inflammatory response and multiple toxicity concerns. Targeting p38MAPK MAPKAPK2 (MK2), one of the downstream substrates of p38 MAPK directly, is expected to be a better anti-inflammatory approach without having any toxicity concerns. In this manuscript, we are reporting biological data of representative MK2 inhibitor to validate its anti-inflammatory potential and a comparison of p38 MAPK and MK2 inhibitors in cell based assays to understand their relative toxicities.

pharmacology and toxicology↗

bioRxiv2022

Septin-Mediated Mechanobiological Reprogramming of T Cell Transmigration and 3D Motility

The all-terrain motility of lymphocytes in tissues and tissue-like gels is best described as amoeboid motility. For amoeboid motility, lymphocytes do not require specific biochemical or structural modifications to the surrounding extracellular matrix. Instead, they rely on changing shape and steric interactions with the microenvironment. However, the exact mechanism of amoeboid motility remains elusive. Here we report that septins shape T cells for amoeboid motility. Specifically, septins form F-actin and alpha-actinin-rich cortical rings at the sites of cortex-indenting collisions of T cells with the extracellular matrix. Cortical rings compartmentalize cells into chains of spherical segments that are spatially conformed to the available lumens, forming transient hourglass-shaped steric locks onto the surrounding collagen fibers. The steric lock facilitates pressure-driven peristaltic propulsion of cytosolic content by individually contracting cell segments. Our results demonstrate that septins provide microenvironment-guided partitioning of actomyosin contractility and steric pivots for amoeboid motility of T cells in tissue-like microenvironments. GLOSSARYO_LISteric interactions - interactions by the means of their spatial collision dependent on objects shapes. C_LIO_LISteric guidance - cell navigation within crowded 3D environments, determined by the available passages around and between steric hindrances. C_LIO_LIPeristaltic treadmilling - locomotion mode by the means of a repeated sequence of polarized cell cortex extension, stabilization, and retraction, accompanied by translocation of nucleus and cytoplasm via circumferential cortex contractility. C_LI Significance StatementT cells can be highly motile, searching for cognate antigens or better yet targets in chimeric antigen receptor therapy settings. However, mechanisms of motility remain elusive for T cells migrating in structurally and biochemically diverse tissues. Here we address one pivotal question of basic and clinical immunology - How T cells achieve the all-terrain motility? Here we decipher and report septin-based T cell motility in a 3D tissue-like environment. Specifically, we show that septins facilitate cell morphological responsiveness to the steric obstacles, i.e., collagen fiber-wise partitioning of actomyosin cortex contractility and cell-obstacle steric interactions. These responses coordinate peristaltic propulsion of the lymphocytes cytosolic content along its individually contracting cell segments, forming the obstacle-avoiding motility, i.e., circumnavigation, shared across various tested lymphocytes.

biophysics↗

bioRxiv2022

Systemic infection of SARS-CoV-2 in free ranging Leopard (Panthera pardus fusca) in India

We report patho-morphological and virological characterization of SARS-CoV-2 in naturally infected, free ranging Indian Leopard (Panthera pardus fusca). Whole genome sequence analysis confirmed infection of Delta variant of SARS-CoV-2, possibly spill over from humans, but the case was detected when infection level had dropped significantly in human population. This report underlines the need for intensive screening of wild animals for keeping track of the virus evolution and development of carrier status of SARS-CoV-2 among wildlife species.

microbiology↗

bioRxiv2021

A Binary Matrix Method to Enumerate, Hierarchically Order and Structurally Classify Peptide Aggregation

Protein aggregation is a common and complex phenomenon in biological processes, yet a robust analysis of this aggregation process remains elusive. The commonly used methods such as center-of-mass to center-of-mass (COM-COM) distance, the radius of gyration (Rg), hydrogen bonding (HB) and solvent accessible surface area (SASA) do not quantify the aggregation accurately. Herein, a new and robust method that uses an aggregation matrix (AM) approach to investigate peptide aggregation in a MD simulation trajectory is presented. A nxn two-dimensional aggregation matrix (AM) is created by using the inter-peptide C-C cut-off distances which are binarily encoded (0 or 1). These aggregation matrices are analyzed to enumerate, hierarchically order and structurally classify the aggregates. Comparison of the present AM method suggests that it is superior to the HB method since it can incorporate non-specific interactions and Rg, COM-COM methods since the cut-off distance is independent of the length of the peptide. More importantly, the present method can structurally classify the peptide aggregates, which the conventional Rg, COM- COM and HB methods fail. The unique selling point of this method is its ability to structurally classify peptide aggregates using two-dimensional matrices. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=160 SRC="FIGDIR/small/470297v2_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@125de8eorg.highwire.dtl.DTLVardef@1367ac5org.highwire.dtl.DTLVardef@1b62e99org.highwire.dtl.DTLVardef@1ad4d05_HPS_FORMAT_FIGEXP M_FIG C_FIG

biophysics↗

bioRxiv2021

Nanobodies as allosteric modulators of Parkinson's disease-associated LRRK2

Mutations in the gene coding for Leucine-Rich Repeat Kinase 2 (LRRK2) are a leading cause of the inherited form of Parkinsons disease (PD), while LRRK2 overactivation is also associated with the more common idiopathic form of PD. LRRK2 is a large multi-domain protein, including a GTPase as well as a Ser/Thr protein kinase domain. Common disease-causing mutations increase LRRK2 kinase activity, presenting LRRK2 as an attractive target for inhibitory drug design. Currently, drug development has mainly focused on ATP-competitive kinase inhibitors. Here, we report the identification and characterization of a variety of Nanobodies that bind to different LRRK2 domains and inhibit or activate LRRK2 activity in cells and in vitro. Importantly, diverse groups of Nanobodies were identified that inhibit LRRK2 kinase activity through a mechanism that does not involve binding to the ATP pocket or even to the kinase domain. Moreover, while certain Nanobodies completely inhibit the LRRK2 kinase activity, we also identified Nanobodies that specifically inhibit the phosphorylation of Rab protein substrates. Finally, in contrast to current type-I kinase inhibitors, the studied kinase-inhibitory Nanobodies did not induce LRRK2 microtubule association. These comprehensively characterized Nanobodies represent versatile tools to study the LRRK2 function and mechanism, and can pave the way toward novel diagnostic and therapeutic strategies for PD.

biochemistry↗

bioRxiv2021

Pathotyping of Newcastle disease virus: A novel single BsaHI digestion method of detection and differentiation of avirulent strains (lentogenic and mesogenic vaccine strains) from virulent virus

We provide a novel single restriction enzyme (RE) (BsaHI) digestion approach for detecting distinct pathotypes of the Newcastle disease virus (NDV). After scanning 4000 F gene nucleotide sequences in the NCBI database, a single RE (BsaHI) digesting site was discovered in the cleavage site. APMV-I "F gene" Class II specific primer-based reverse transcriptase PCR (RT-PCR) was utilized to amplify a 535 bp fragment, which was then digested with a single RE (BsaHI) for pathotyping avian NDV field isolates and pigeon paramyxovirus-1 isolates. The avirulent (lentogenic and mesogenic strains) produce 189 and 346 bp fragments, respectively, but the result in velogenic strains remains undigested with 535 bp fragments. In addition, 45 field NDV isolates and 8 vaccine strains were used to confirm the approach. The sequence-based analysis also agrees with the data obtained utilizing the single RE (BsaHI) digestion approach. The proposed technique had the potential to distinguish between avirulent and virulent strains in a short space of time, making it valuable in NDV surveillance and monitoring research.

microbiology↗

bioRxiv2021

Mechanical counterbalance of kinesin and dynein motors in microtubular network regulates cell mechanics, 3D architecture, and mechanosensing

Microtubules (MTs) and MT motor proteins form active 3D networks made of unstretchable cables with rod-like bending mechanics that provide cells with a dynamically changing structural scaffold. In this study, we report an antagonistic mechanical balance within the dynein-kinesin microtubular motor system. Dynein activity drives microtubular network inward compaction, while isolated activity of kinesins bundles and expands MTs into giant circular bands that deform the cell cortex into discoids. Furthermore, we show that dyneins recruit MTs to sites of cell adhesion increasing topographic contact guidance of cells, while kinesins antagonize it via retraction of MTs from sites of cell adhesion. Actin-to-microtubules translocation of septin-9 enhances kinesins-MTs interactions, outbalances activity of kinesins over dyneins and induces discoid architecture of cells. These orthogonal mechanisms of MT network reorganization highlight the existence of an intricate mechanical balance between motor activities of kinesins and dyneins that controls cell 3D architecture, mechanics, and cell-microenvironment interactions.

biophysics↗

bioRxiv2021

Characterization of a novel mesophilic CTP-dependent riboflavin kinase and rational engineering to create its thermostable homologs

Flavins play a central role in cellular metabolism as molecules that catalyze a wide range of oxidation-reduction reactions in living organisms. Several interesting variations in flavin biosynthesis exist among the domains of life, and the analysis of enzymes on this pathway have put forth many unique structural and mechanistic insights till date. The CTP-dependent riboflavin kinase in archaea is one such example - unlike most kinase enzymes that use adenosine triphosphate to conduct phosphorylation reactions, riboflavin kinases from archaea utilizes cytidine triphosphate (CTP) to phosphorylate riboflavin to produce flavin mononucleotide (FMN). In this study, we present the characterization of a new mesophilic archaeal riboflavin kinase homolog from Methanococcus maripaludis (MmpRibK), which is linked closely in sequence to the previously characterized thermophilic homolog from Methanocaldococcus jannaschii (MjRibK). We reconstitute the activity of the CTP-dependent MmpRibK, determine its kinetic parameters, and analyse the molecular factors that contribute to the uncommon properties of this class of enzymes. Specifically, we probe the flexibility of MmpRibK and MjRibK under varying temperatures and the role of a metal ion for substrate binding and catalysis using molecular dynamics simulation and a series of experiments. Furthermore, based on the high degree of sequence similarity between the mesophilic MmpRibK and the thermophilic MjRibK, we use comparative analysis and site-directed mutagenesis to establish a set of the residues that are responsible for the thermostability of the enzyme without any loss in activity or substrate specificity. Our work contributes to the molecular understanding of flavin biosynthesis in archaea through the characterization of the first mesophilic CTP-dependent riboflavin kinase. Finally, it validates the role of salt bridges and rigidifying amino acid residues in imparting thermostability to enzymes, with implications in enzyme engineering and biotechnological applications.

biochemistry↗

bioRxiv2021

Vibrio cholerae ParE2 toxin modulates its operon transcription by stabilization of an antitoxin DNA ruler

The parDE2 operon of Vibrio cholerae encodes a type II TA system, which is one of three loci in the superintegron of small chromosome II that show modest similarity to the parDE operon of plasmid RK2. ParE2, like plasmid RK2-encoded ParE, inhibits DNA gyrase, an essential topoisomerase that is also the target of quinolone antibacterial agents. Mechanistic understanding on ParE2 toxin inhibition by direct interaction with its cognate antitoxin and transcriptional autoregulation of the TA system are currently lacking. ParD2, the ribbon-helix-helix (RHH) antitoxin, auto-represses the parDE2 promoter. This repression is enhanced by ParE2, which therefore functions as a transcriptional co-repressor. Here we present protein-DNA interaction studies and high-resolution X-ray structures of the ParD2:ParE2 complex and isolated ParD2 antitoxin, revealing the basis of toxin inhibition and autoregulation of the TA operon by conditional cooperativity. Native mass spectrometry, SAXS and MALS studies confirm the presence of different oligomerization states of ParD2 in solution and the role of the DNA-binding hexameric ParD26:ParE22 assembly in transcriptional repression.

microbiology↗

bioRxiv2021

Entropic pressure controls oligomerization of Vibrio cholerae ParD2 antitoxin

ParD2 is the antitoxin component of the parDE2 toxin-antitoxin module from Vibrio cholerae and consists of an ordered DNA binding domain followed by an intrinsically disordered ParE-neutralizing domain. In absence of the C-terminal IDP domain, VcParD2 crystallizes as a doughnut-shaped hexadecamer formed by the association of eight dimers. This assembly is stabilized via hydrogen bonds and salt bridges rather than hydrophobic contacts. In solution, oligomerization of the full-length protein is restricted to a stable, open 10-mer or 12-mer, likely as a consequence of entropic pressure from the IDP tails. The relative positioning of successive VcParD2 dimers mimics the arrangement of Streptococcus agalactiae CopG dimers on their operator and allows for an extended operator to wrap around the VcParD2 oligomer.

biophysics↗

bioRxiv2020

Binding of dsRNA by D. melanogaster Dicer-2 is substrate-dependent and regulated by Loquacious-PD

Drosophila melanogaster Dicer-2 is a large, multidomain protein that cleaves double-stranded RNA (dsRNA) into small interfering RNAs in a terminus-dependent manner as part of the RNA interference pathway. We characterize the local binding environment involved in this substrate-selective molecular recognition event by monitoring the time-resolved photophysics of a cyanine dye linked to the dsRNA terminus. We observe substantial changes in the molecular rigidity and local freedom of motion of the probe as a function of distinct conformations of the biomolecular complex between Dicer-2 and dsRNA as a function of dsRNA termini, the presence of regulatory proteins, and the addition of a biochemical energy source (ATP) or a non-hydrolysable equivalent (ATP-{gamma}S). With a clustering analysis based solely on these molecular-scale measures of the local binding environment at the dsRNA terminus, we identify sub-populations of similar conformations that define distinct modes of molecular recognition which are correlated with biochemical activity. These observations reveal the important role of substrate-selective molecular recognition properties for proteins with multiple domains that can bind RNA, regulatory proteins, and cofactors. STATEMENT OF SIGNIFICANCEThe molecular-scale determinants of protein-RNA binding remain elusive, particularly when different subunits of a single protein confer specificity toward small structural differences of their RNA partners. An important case is that of Drosophila melanogaster Dicer-2, a critical component of the antiviral RNA interference response. Dicer-2 discriminates between double stranded RNA with blunt or 3 overhang termini, a feature suggested to mediate recognition of "self" vs. "non-self" substrates. We study these interactions at the binding site with a fluorescent label at the RNA terminus, monitoring intramolecular and collective measures of flexibility to report on the local environment. Dicer-2 has distinct modes of molecular recognition which are regulated by accessory proteins and ATP, leading to different conformations and tuning biochemical activity.

biophysics↗

bioRxiv2020

Targeting Vitamin-D receptor (VDR) by a small molecule antagonist MeTC7 inhibits PD-L1 but controls THMYCN neuroblastoma growth PD-L1 independently

Vitamin-D receptor (VDR) mRNA is enriched in malignant lung, ovarian and pancreatic tissues and showed poor prognoses. Calcitriol and stable or CRISPR-directed VDR upregulation increased PD-L1mRNA and protein expression in cancer cells in-vitro. A ChIP assay showed the binding of VDR with VDREPD-L1. Stattic, a STAT3 phosphorylation inhibitor blocked calcitriol or VDR overexpression induced PD-L1 upregulation. MeTC7, a VDR antagonist developed by us, reduced PD-L1 expression on macrophages, ovarian, lung, breast, and pancreatic cancer cells in-vitro. In radiotherapy inducible PD-L1 model of orthotopic MC38 murine colon cancer, MeTC7 decreased PD-L1 surface expression, suppressed inflammatory monocytes (IMs) population and increased intra-tumoral CD69+PD1+CD8+T-cells. Intriguingly, MeTC7 reduced TH-MYCN transgenic neuroblastoma tumor growth without affecting PD-L1 and tumor immune milieu. In summary, Vitamin-D/VDR drives PD-L1 expression on cancer cells via STAT-3. Inhibiting VDR exhibited anti-checkpoint effects in orthotopic colon tumors, whereas PDL1-independent and anti-VDR/MYCN effects controlled growth of transgenic neuroblastoma and xenografted tumors. SummaryVitamin-D/VDR induces PD-L1 expression on cancer cells via STAT-3; and targeting VDR by a novel small molecule antagonist MeTC7 exhibits both anti-PD-L1 and anti-VDR/MYCN effects in tumor models.

cancer biology↗

bioRxiv2020

Systems Biology behind immunoprotection of both Sheep and Goats after Sungri/96 PPRV vaccination

Immune response is a highly coordinated cascade involving all the subsets of PBMCs. In this study, RNA-Seq analysis of PBMC subsets - CD4+, CD8+, CD14+, CD21+ and CD335+ cells from day 0 and day 5 of Sungri/96 Peste des Petits Ruminants vaccinated sheep and goats was done to delineate the systems biology behind immune - protection of the vaccine in sheep and goats. Assessment of the immune response processes enriched by the differentially expressed genes in all the subsets suggested a strong dysregulation towards development of early inflammatory microenvironment, which is very much required for differentiation of monocytes to macrophages, and for activation and migration of dendritic cells into the draining lymph nodes. The protein - protein interaction networks among the antiviral molecules (IFIT3, ISG15, MX1, MX2, RSAD2, ISG20, IFIT5 and IFIT1) and common DEGs across PBMCs subsets in both the species identified ISG15 to be an ubiquitous hub, that helps in orchestrating antiviral host response against PPRV. IRF7 was found to be the key master regulator activated in most of the subsets in sheep and goats. Most of the pathways were found to be inactivated in B - lymphocytes of both the species indicating that 5 dpv is too early a time point for the B - lymphocytes to react. The cell mediated immune response and humoral immune response pathways were found more enriched in goats than in sheep. Though, animals from both the species survived the challenge, a contrast in pathway activation was observed in CD335+ cells. ImportancePeste des petits ruminants (PPR) by PPRV is an OIE listed acute, contagious transboundary viral disease of small ruminants. Attenuated Sungri/96 PPRV vaccine used all over India against this PPR, provides long-lasting robust innate and adaptive immune response. The early antiviral response was found mediated through type I interferon independent ISGs expression. However, systems biology behind this immune response is unknown. In this study, in vivo transcriptome profiling of PBMC subsets (CD4+, CD8+, CD14+, CD21+ and CD335+) in vaccinated goats and sheep (at 5 days of post vaccination) was done to understand this systems biology. Though there are a few differences in the systems biology across cells (specially the NK cells) between sheep and goats, the co-ordinated response that is inclusive of all the cell subsets was found to be towards induction of strong innate immune response, which is needed for an appropriate adaptive immune response.

systems biology↗

bioRxiv2020

KSHV-encoded vCyclin can modulate HIF1α levels to promote DNA replication in hypoxia

The cellular adaptive response to hypoxia, mediated by high HIF1 levels includes metabolic reprogramming, restricted DNA replication and cell division. In contrast to healthy cells, the genome of cancer cells, and Kaposis sarcoma associated herpesvirus (KSHV) infected cells maintains replication in hypoxia. We show that KSHV infection, despite promoting expression of HIF1 in normoxia, can also restricts transcriptional activity, and promoted its degradation in hypoxia. KSHV-encoded vCyclin, expressed in hypoxia, mediated HIF1a cytosolic translocation, and its degradation through a non-canonical lysosomal pathway. Attenuation of HIF1 levels by vCyclin allowed cells to bypass the block to DNA replication and cell proliferation in the hypoxia. These results demonstrated that KSHV utilizes a unique strategy to balance HIF1 levels to overcome replication arrest and induction of the oncogenic phenotype, which are dependent on the levels of oxygen in the microenvironment.

microbiology↗

bioRxiv2020

Transgressive segregation for salt tolerance in rice due to physiological coupling and uncoupling and genetic network rewiring

Transgressive segregation is common in plant breeding populations, where a small minority of recombinants are outliers relative to parental phenotypes. While this phenomenon has been attributed to complementation and epistatic effects, the physiological, biochemical, and molecular bases have not been fully illuminated. By systems-level scrutiny of the IR29 x Pokkali recombinant inbred population of rice, we addressed the hypothesis that novel salt tolerance phenotypes are created by positive or negative coupling or uncoupling effects and novel regulatory networks. Hyperspectral profiling distinguished the transgressive individuals in terms of stress penalty to growth. Non-parental network signatures that led to either optimal or non-optimal integration of developmental with stress-related mechanisms were evident at the macro-physiological, biochemical, metabolic, and transcriptomic levels. The large positive net gain in super-tolerant progeny was due to ideal complementation of beneficial traits, while shedding antagonistic traits. Super-sensitivity was explained by the stacking of multiple antagonistic traits and loss of major beneficial traits. The mechanisms elucidated in this study are consistent with the Omnigenic Theory, emphasizing the synergy or lack thereof between core and peripheral components. This study supports a breeding paradigm based on genomic modeling to create the novel adaptive phenotypes for the crops of the 21st century.

genetics↗

bioRxiv2020

Rub1/NEDD8, a ubiquitin-like modifier, is also a ubiquitin modifier

Of all ubiquitin-like small protein modifiers, Rub1/NEDD8 is the closest kin of ubiquitin in sequence and in structure. Despite their profound similarities, prevalence of ubiquitin and of Rub1 is starkly different: targets of ubiquitin modification reach into the thousands, whereas unique targets of Rub1/NEDD8 appear limited to one family of proteins, Cullins. This distinction is likely due to dedicated E1 activating enzymes that select either one or the other and relay the modifier until it is covalently attached to a target. To convert typical neddylation targets for modification by ubiquitin, and vice versa, we designed reciprocal substitutions at position 72 of Rub1 and of ubiquitin to render them substrates for activation by their non-cognate E1 activating enzymes. We found that this single amino acid is sufficient to distinguish between Ub and Rub1 in living cells, and determine their targets. Thus, modification of Cullins by UbR72T could compensate for loss of Rub1, even as it maintained its ability to polymerize and direct conjugates for degradation. Conversely, Rub1T72R activated by ubiquitin-activating enzyme entered into the ubiquitination cascade, however was not efficiently polymerized, essentially capping polyubiquitin chains. Upon shortage of free ubiquitin under stress, even native Rub1 spilled-over into the ubiquitinome suppressing polyubiquitination. By contrast, the need to maintain monomeric modifications on unique targets is a likely explanation for why the Rub1-activating enzyme strictly discriminates against ubiquitin. Swapping Rub1 and ubiquitin signals uncovered a reason for maintaining two separate pathways across eukaryotic kingdom.

biochemistry↗

bioRxiv2020

Prediction analysis of SARS-COV-2 entry in Livestock and Wild animals

BackgroundSARS-CoV-2 is a viral pathogen causing life-threatening disease in human. Interaction between spike protein of SARS-CoV-2 and ACE2 receptor on the cells is a potential factor in the infectivity of a host. The interaction of SARS-CoV-2 spike receptor-binding domain with its receptor - ACE2, in different hosts was evaluated to understand and predict viral entry. The protein and nucleotide sequences of ACE2 were initially compared across different species to identify key differences among them. The ACE2 receptor of various species was homology modeled (6LZG, 6M0J, and 6VW1 as a reference), and its binding ability to the spike ACE2 binding domain of SARS-CoV-2 was assessed. Initially, the spike binding parameters of ACE2 of known infected and uninfected species were compared with each Order (of animals) as a group. Finally, a logistic regression model vis-a-vis the spike binding parameters of ACE2 (considering data against 6LZG and 6M0J) was constructed to predict the probability of viral entry in different hosts. ResultsPhylogeny and alignment comparison did not lead to any meaningful conclusion on viral entry in different hosts. Out of several spike binding parameters of ACE2, a significant difference between the known infected and uninfected species was observed for six parameters. However, these parameters did not specifically categorize the Orders (of animals) into infected or uninfected. The logistic regression model constructed revealed that in the mammalian class, most of the species of Carnivores, Artiodactyls, Perissodactyls, Pholidota, and Primates had high probability of viral entry. However, among the primates, African Elephant had low probability of viral entry. Among rodents, hamsters were highly probable for viral entry with rats and mice having a medium to low probability. Rabbits have a high probability of viral entry. In Birds, ducks have a very low probability, while chickens seemed to have medium probability and turkey showed the highest probability of viral entry. ConclusionsMost of the species considered in this study showed high probability of viral entry. This study would prompt us to closely follow certain species of animals for determining pathogenic insult by SARS-CoV-2 and for determining their ability to act as a carrier and/or disseminator.

microbiology↗