scholarly journals Identification of the Primary Factors Determining the Specificity of Human VKORC1 Recognition by Thioredoxin-Fold Proteins

2021 ◽  
Vol 22 (2) ◽  
pp. 802
Author(s):  
Maxim Stolyarchuk ◽  
Julie Ledoux ◽  
Elodie Maignant ◽  
Alain Trouvé ◽  
Luba Tchertanov

Redox (reduction–oxidation) reactions control many important biological processes in all organisms, both prokaryotes and eukaryotes. This reaction is usually accomplished by canonical disulphide-based pathways involving a donor enzyme that reduces the oxidised cysteine residues of a target protein, resulting in the cleavage of its disulphide bonds. Focusing on human vitamin K epoxide reductase (hVKORC1) as a target and on four redoxins (protein disulphide isomerase (PDI), endoplasmic reticulum oxidoreductase (ERp18), thioredoxin-related transmembrane protein 1 (Tmx1) and thioredoxin-related transmembrane protein 4 (Tmx4)) as the most probable reducers of VKORC1, a comparative in-silico analysis that concentrates on the similarity and divergence of redoxins in their sequence, secondary and tertiary structure, dynamics, intraprotein interactions and composition of the surface exposed to the target is provided. Similarly, hVKORC1 is analysed in its native state, where two pairs of cysteine residues are covalently linked, forming two disulphide bridges, as a target for Trx-fold proteins. Such analysis is used to derive the putative recognition/binding sites on each isolated protein, and PDI is suggested as the most probable hVKORC1 partner. By probing the alternative orientation of PDI with respect to hVKORC1, the functionally related noncovalent complex formed by hVKORC1 and PDI was found, which is proposed to be a first precursor to probe thiol–disulphide exchange reactions between PDI and hVKORC1.

2020 ◽  
Vol 17 (2) ◽  
pp. 125-132
Author(s):  
Marjanu Hikmah Elias ◽  
Noraziah Nordin ◽  
Nazefah Abdul Hamid

Background: Chronic Myeloid Leukaemia (CML) is associated with the BCRABL1 gene, which plays a central role in the pathogenesis of CML. Thus, it is crucial to suppress the expression of BCR-ABL1 in the treatment of CML. MicroRNA is known to be a gene expression regulator and is thus a good candidate for molecularly targeted therapy for CML. Objective: This study aims to identify the microRNAs from edible plants targeting the 3’ Untranslated Region (3’UTR) of BCR-ABL1. Methods: In this in silico analysis, the sequence of 3’UTR of BCR-ABL1 was obtained from Ensembl Genome Browser. PsRNATarget Analysis Server and MicroRNA Target Prediction (miRTar) Server were used to identify miRNAs that have binding conformity with 3’UTR of BCR-ABL1. The MiRBase database was used to validate the species of plants expressing the miRNAs. The RNAfold web server and RNA COMPOSER were used for secondary and tertiary structure prediction, respectively. Results: In silico analyses revealed that cpa-miR8154, csi-miR3952, gma-miR4414-5p, mdm-miR482c, osa-miR1858a and osa-miR1858b show binding conformity with strong molecular interaction towards 3’UTR region of BCR-ABL1. However, only cpa-miR- 8154, osa-miR-1858a and osa-miR-1858b showed good target site accessibility. Conclusion: It is predicted that these microRNAs post-transcriptionally inhibit the BCRABL1 gene and thus could be a potential molecular targeted therapy for CML. However, further studies involving in vitro, in vivo and functional analyses need to be carried out to determine the ability of these miRNAs to form the basis for targeted therapy for CML.


2008 ◽  
Vol 82 (24) ◽  
pp. 12384-12391 ◽  
Author(s):  
Amanda R. Howard ◽  
Tatiana G. Senkevich ◽  
Bernard Moss

ABSTRACT During vaccinia virus replication, mature virions (MVs) are wrapped with cellular membranes, transported to the periphery, and exported as extracellular virions (EVs) that mediate spread. The A26 protein is unusual in that it is present in MVs but not EVs. This distribution led to a proposal that A26 negatively regulates wrapping. A26 also has roles in the attachment of MVs to the cell surface and incorporation of MVs into proteinaceous A-type inclusions in some orthopoxvirus species. However, A26 lacks a transmembrane domain, and nothing is known regarding how it associates with the MV, regulates incorporation of the MV into inclusions, and possibly prevents EV formation. Here, we provide evidence that A26 forms a disulfide-bonded complex with A27 that is anchored to the MV through a noncovalent interaction with the A17 transmembrane protein. In the absence of A27, A26 was unstable, and only small amounts were detected. The interaction of A26 with A27 depended on a C-terminal segment of A26 with 45% amino acid identity to A27. Deletion of A26 failed to enhance EV formation by vaccinia virus, as had been predicted. Nevertheless, the interaction of A26 and A27 may have functional significance, since each is thought to mediate binding to cells through interaction with laminin and heparan sulfate, respectively. We also found that A26 formed a noncovalent complex with A25, a truncated form of the cowpox virus A-type inclusion matrix protein. The latter association suggests a mechanism for incorporation of virions into A-type inclusions in other orthopoxvirus strains.


2021 ◽  
Author(s):  
Key-Hwan Lim ◽  
Sumin Yang ◽  
Sung-Hyun Kim ◽  
Jae-Yeol Joo

Abstract Background Numerous studies have been conducted on different aspects of the COVID-19 (coronavirus disease 2019) pandemic, which is caused by SARS-CoV-2, since its emergence in late 2019. Mutual relations among SARS-CoV-2 and neuro-pathophysiological phenomena are continuously being demonstrated, and several underlying diseases, such as those in the elderly, are positively correlated with susceptibility to SARS-CoV-2 infection. The expression of angiotensin converting enzyme 2 (ACE2), which is required for SARS-CoV-2 infection, was recently demonstrated to be increased in Alzheimer’s disease (AD) patients. Methods Recent preclinical studies have shown that Neuropilin-1 (NRP1), which is a transmembrane protein with roles in neuronal development, axonal outgrowth, and angiogenesis, also plays a role in the infectivity of SARS-CoV-2. Thus, we hypothesized that NRP1 may be upregulated in AD patients and that a correlation between AD and SARS-CoV-2 NRP1-mediated infectivity may exist. We used an AD mouse model that mimics AD and performed high throughput total RNA-seq with brain tissue and whole blood. For quantification of NPR1 in AD, brain tissues and blood were subjected to western blotting and RT-qPCR analysis. In silico analysis for NRP1 expression in AD patients has been performed on the human hippocampus data sets (GSE4226, GSE1297). Results Many cases of severe symptom of COVID-19 are concentrated in elderly group who have complications such as diabetes, degenerative disease, and brain disorders. Total RNA-seq analysis showed that Nrp1 gene was commonly overexpressed in AD model. Similar to ACE2, NRP1 protein also strongly expressed in the AD brain tissues. Interestingly, in silico analysis revealed that the level of expression for NRP1 was distinct at age and AD progression. Conclusions Given that the NRP1 is highly expressed in AD, it will be important to understand and predict that NRP1 may a risk factor for SARS-CoV-2 infection in AD patients. This will support to development of potential therapeutic drug to reduce SARS-CoV-2 transmission.


Genes ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1765
Author(s):  
Noluthando Manyisa ◽  
Isabelle Schrauwen ◽  
Leonardo Alves de Souza Rios ◽  
Shaheen Mowla ◽  
Cedrik Tekendo-Ngongang ◽  
...  

Hearing impairment (HI) is a sensory disorder with a prevalence of 0.0055 live births in South Africa. DNA samples from a South African family presenting with progressive, autosomal dominant non-syndromic HI were subjected to whole-exome sequencing, and a novel monoallelic variant in REST [c.1244GC; p.(C415S)], was identified as the putative causative variant. The co-segregation of the variant was confirmed with Sanger Sequencing. The variant is absent from databases, 103 healthy South African controls, and 52 South African probands with isolated HI. In silico analysis indicates that the p.C415S variant in REST substitutes a conserved cysteine and results in changes to the surrounding secondary structure and the disulphide bonds, culminating in alteration of the tertiary structure of REST. Localization studies using ectopically expressed GFP-tagged Wild type (WT) and mutant REST in HEK-293 cells show that WT REST localizes exclusively to the nucleus; however, the mutant protein localizes throughout the cell. Additionally, mutant REST has an impaired ability to repress its known target AF1q. The data demonstrates that the identified mutation compromises the function of REST and support its implication in HI. This study is the second report, worldwide, to implicate REST in HI and suggests that it should be included in diagnostic HI panels.


Author(s):  
Vinod P. Sinoorkar ◽  
Snehal M. Mathe ◽  
Neha Guttikonda

Dengue fever is frequently born viral infection caused by female mosquito Aedes egypti. Transmission of dengue infection is transfer from one host to another by infected mosquito bite. Dengue virus is categorized into various serotypes on the basis of their genetic material variable. Dengue fever and dengue haemorrhagic fever is serious risk factor to Mankind Nowdays there is no specific vaccine to treat the dengue infection. There is need to design potent antiviral vaccine against dengue fever. NS2B-NS3 act as potent drug target in dengue fever. Hence our present work to achieve to understand detail molecular properties of NS2B-NS3 protein by retrieving its amino acid sequence from protein database like PDB. Analysis of physicochemical parameters, secondary and tertiary structure prediction. structure visualization is done by using Rasmol structure visualization tool. Predicted model is validated using procheck analysis. This all information gives primary information for future work to perform computer aided drug design against dengue fever.


2020 ◽  
Vol 21 (11) ◽  
pp. 4013
Author(s):  
Monika Adamczyk-Popławska ◽  
Zuzanna Tracz-Gaszewska ◽  
Przemysław Lasota ◽  
Agnieszka Kwiatek ◽  
Andrzej Piekarowicz

HP1 is a temperate bacteriophage, belonging to the Myoviridae family and infecting Haemophilus influenzae Rd. By in silico analysis and molecular cloning, we characterized lys and hol gene products, present in the previously proposed lytic module of HP1 phage. The amino acid sequence of the lys gene product revealed the presence of signal-arrest-release (SAR) and muraminidase domains, characteristic for some endolysins. HP1 endolysin was able to induce lysis on its own when cloned and expressed in Escherichia coli, but the new phage release from infected H. influenzae cells was suppressed by inhibition of the secretion (sec) pathway. Protein encoded by hol gene is a transmembrane protein, with unusual C-out and N-in topology, when overexpressed/activated. Its overexpression in E. coli did not allow the formation of large pores (lack of leakage of β-galactosidase), but caused cell death (decrease in viable cell count) without lysis (turbidity remained constant). These data suggest that lys gene encodes a SAR-endolysin and that the hol gene product is a pinholin. HP1 SAR-endolysin is responsible for cell lysis and HP1 pinholin seems to regulate the cell lysis and the phage progeny release from H. influenzae cells, as new phage release from the natural host was inhibited by deletion of the hol gene.


1999 ◽  
Vol 345 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Angélique AUGUSTIN ◽  
Hélène MULLER-STEFFNER ◽  
Francis SCHUBER

Bovine spleen ecto-NAD+ glycohydrolase, an archetypal member of the mammalian membrane-associated NAD(P)+ glycohydrolase enzyme family (EC 3.2.2.6), displays catalytic features similar to those of CD38, i.e. a protein originally described as a lymphocyte differentiation marker involved in the metabolism of cyclic ADP-ribose and signal transduction. Using amino acid sequence information obtained from NAD+ glycohydrolase and from a truncated and hydrosoluble form of the enzyme (hNADase) purified to homogeneity, a full-length cDNA clone was obtained. The deduced sequence indicates a protein of 278 residues with a molecular mass of 31.5 kDa. It predicts that bovine ecto-NAD+ glycohydrolase is a type II transmembrane protein, with a very short intracellular tail. The bulk of the enzyme, which is extracellular and contains two potential N-glycosylation sites, yields the fully catalytically active hNADase which is truncated by 71 residues. Transfection of HeLa cells with the full-length cDNA resulted in the expression of the expected NAD+ glycohydrolase, ADP-ribosyl cyclase and GDP-ribosyl cyclase activities at the surface of the cells. The bovine enzyme, which is the first ‘classical’ NAD(P)+ glycohydrolase whose structure has been established, presents a particularly high sequence identity with CD38, including the presence of 10 strictly conserved cysteine residues in the ectodomain and putative catalytic residues. However, it lacks two otherwise conserved cysteine residues near its C-terminus. Thus hNADase, the truncated protein of 207 amino acids, represents the smallest functional domain endowed with all the catalytic activities of CD38/NAD+ glycohydrolases so far identified. Altogether, our data strongly suggest that the cloned bovine spleen ecto-NAD+ glycohydrolase is the bovine equivalent of CD38.


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