scholarly journals Natural Occurring Non-Synonymous Single Nucleotide Polymorphisms in Integrase and RNase H Regulate Assembly and Autoprocessing of HIV-1

2021 ◽  
Author(s):  
Tomozumi Imamichi ◽  
John G. Bernbaum ◽  
Sylvain Laverdure ◽  
Jun Yang ◽  
Qian Chen ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Rnase H ◽  
Viral Fitness ◽  
Nucleotide Polymorphisms ◽  
Virus Release ◽  
Single Nucleotide ◽  
Hiv Rna ◽  
A Genome ◽  
The Impact ◽  
Hiv 1

AbstractRecently, a genome-wide association study using plasma HIV RNA reported that 14 naturally occurring non-synonymous single nucleotide polymorphisms (SNPs) in HIV derived from anti-retrovirus naïve patients were associated with virus load (VL). However, the impact of each mutation on viral fitness was not investigated. Here, we constructed a series of HIV variants encoding each SNP using site-directed mutagenesis and examined their replicative abilities and biological properties. An HIV variant containing Met-to-Ile change at codon 50 in integrase (HIV(IN:M50I)) was found an impaired virus. Despite the mutation being in integrase, a quantification assay demonstrated that the virus release was significantly suppressed (P<0.001). Transmission electron microscopy analyses revealed that the accumulation of abnormal shapes of buds on the plasma membrane and the released virus particles retained immature forms. Western blot analysis demonstrated a defect in autoprocessing of GagPol and Gag polyproteins in the HIV(IN:M50I) particles. Förster Resonance Energy Transfer (FRET) assay displayed that GagPol containing IN:M50I (GagPol(IN:M50I)) significantly increased the efficiency of homodimerization (P<0.05) and heterodimerization with Gag (P<0.001), compared to GagPol(WT). HIV replication assay using a series of variants of HIV(IN:M50I) elucidated that the C-terminus residues, Asn at codon 288, plays a key role in the defect and the impaired maturation and replication capability was rescued by two other VL-associated SNPs, Ser-to-Asn change at codon 17 in integrase or Asn-to-Ser change at codon 79 in RNase H. These data demonstrate that Gag and GagPol assembly, virus release and autoprocessing are not only regulated by integrase but also RNase H.ImportanceA nascent HIV-1 is noninfectious. To become an infectious virus, Gag and GagPol polyproteins in the particles need to be cleaved by mature HIV protease (PR). PR is initially translated as an inactive embedded enzyme in a GagPol polyprotein. The embedded PR in homodimerized GagPol polyproteins catalyzes a proteolytic reaction to release the mature PR. This excision step by a self-cleavage is called autoprocessing. Here, during the evaluation of roles of naturally emerging non-synonymous SNPs in HIV RNA, we found that autoprocessing is inhibited by Met-to-Ile change at codon 50 in integrase in GagPol which increases the efficiency of heterodimerization with Gag. This defect was recovered by co-existing of other SNPs: Ser-to-Asn change at codon 17 in integrase or Asn-to-Ser mutation at codon 79 in RNase H, suggesting that autoprocessing is regulated by not only integrase but also RNase H in GagPol polyprotein.

Natural Occurring Polymorphisms in HIV-1 Integrase and RNase H Regulate Viral Release and Autoprocessing

2021 ◽  
Author(s):  
Tomozumi Imamichi ◽  
John G. Bernbaum ◽  
Sylvain Laverdure ◽  
Jun Yang ◽  
Qian Chen ◽  
...  
Keyword(s):  
Genome Wide Association Study ◽  
Rnase H ◽  
Viral Fitness ◽  
Hiv Protease ◽  
Virus Release ◽  
Transmission Electron Microscopy Analysis ◽  
Hiv Rna ◽  
A Genome ◽  
The Impact ◽  
Hiv 1

Recently, a genome-wide association study using plasma HIV RNA from antiretroviral therapy naïve patients reported that 14 naturally occurring non-synonymous single nucleotide polymorphisms (SNPs) in HIV derived from anti-retrovirus drugs naïve patients were associated with virus load (VL). Those SNPs were detected in reverse transcriptase, RNase H, integrase, envelope, and Nef. However, the impact of each mutation on viral fitness was not investigated. Here, we constructed a series of HIV variants encoding each SNP and examined their replicative abilities. An HIV variant containing Met-to-Ile change at codon 50 in integrase (HIV(IN:M50I)) was found as an impaired virus. Despite the mutation being in integrase, the virus release was significantly suppressed (P<0.001). Transmission electron microscopy analysis revealed that abnormal bud accumulation on the plasma membrane and the released virus particles retained immature forms. Western blot analysis demonstrated a defect in autoprocessing of GagPol and Gag polyproteins' autoprocessing in the HIV(IN:M50I) particles, although Förster Resonance Energy Transfer (FRET) assay displayed that GagPol containing IN:M50I forms homodimer with a similar efficiency with GagPol (WT). The impaired maturation and replication were rescued by two other VL-associated SNPs, Ser-to-Asn change at codon 17 of integrase or Asn-to-Ser change at codon 79 of RNase H. These data demonstrate that Gag and GagPol assembly, virus release, and autoprocessing are not only regulated by integrase but also RNase H. Importance A nascent HIV-1 is a noninfectious viral particle. Cleaving Gag and GagPol polyproteins in the particle by mature HIV protease (PR), the nascent virus becomes an infectious virus. PR is initially translated as an inactive embedded enzyme in a GagPol polyprotein. The embedded PR in homodimerized GagPol polyproteins catalyzes a proteolytic reaction to release the mature PR. This excision step by a self-cleavage is called autoprocessing. Here, during the evaluation of the roles of naturally emerging non-synonymous SNPs in HIV RNA, we found that autoprocessing is inhibited by Met-to-Ile change at codon 50 in integrase GagPol. Co-existing other SNPs, Ser-to-Asn change at codon 17 in integrase or Asn-to-Ser mutation at codon 79 in RNase H, recovered this defect, suggesting that autoprocessing is regulated by not only integrase but also RNase H in GagPol polyprotein.

scholarly journals Nonsynonymous single nucleotide polymorphisms of NHE3 differentially decrease NHE3 transporter activity

2015 ◽  
Vol 308 (9) ◽  
pp. C758-C766 ◽  
Author(s):  
Xinjun Cindy Zhu ◽  
Rafiquel Sarker ◽  
John R. Horton ◽  
Molee Chakraborty ◽  
Tian-E Chen ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Large Fraction ◽  
Regulatory Protein ◽  
Nucleotide Polymorphisms ◽  
Genetic Determinants ◽  
Single Nucleotide ◽  
Mutant Proteins ◽  
Homologous Protein ◽  
Genetic Abnormalities ◽  
The Impact

Genetic determinants appear to play a role in susceptibility to chronic diarrhea, but the genetic abnormalities involved have only been identified in a few conditions. The Na+/H+ exchanger 3 (NHE3) accounts for a large fraction of physiologic intestinal Na+ absorption. It is highly regulated through effects on its intracellular COOH-terminal regulatory domain. The impact of genetic variation in the NHE3 gene, such as single nucleotide polymorphisms (SNPs), on transporter activity remains unexplored. From a total of 458 SNPs identified in the entire NHE3 gene, we identified three nonsynonymous mutations (R474Q, V567M, and R799C), which were all in the protein's intracellular COOH-terminal domain. Here we evaluated whether these SNPs affect NHE3 activity by expressing them in a mammalian cell line that is null for all plasma membrane NHEs. These variants significantly reduced basal NHE3 transporter activity through a reduction in intrinsic NHE3 function in variant R474Q, abnormal trafficking in variant V567M, or defects in both intrinsic NHE3 function and trafficking in variant R799C. In addition, variants NHE3 R474Q and R799C failed to respond to acute dexamethasone stimulation, suggesting cells with these mutant proteins might be defective in NHE3 function during postprandial stimulation and perhaps under stressful conditions. Finally, variant R474Q was shown to exhibit an aberrant interaction with calcineurin B homologous protein (CHP), an NHE3 regulatory protein required for basal NHE3 activity. Taken together, these results demonstrate decreased transport activity in three SNPs of NHE3 and provide mechanistic insight into how these SNPs impact NHE3 function.

Single nucleotide polymorphisms in PNPLA3, ADAR-1, and IFIH1 are associated with advanced liver fibrosis in patients co-infected with HIV-1/HCV

AIDS ◽  
2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Sandra Franco ◽  
Judith Horneros ◽  
Laura Soldevila ◽  
Dan Ouchi ◽  
Iván Galván-Femenía ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Advanced Liver Fibrosis ◽  
Hiv 1

scholarly journals The Impact of Single Nucleotide Polymorphisms on Human Aldehyde Oxidase

2012 ◽  
Vol 40 (5) ◽  
pp. 856-864 ◽  
Author(s):  
Tobias Hartmann ◽  
Mineko Terao ◽  
Enrico Garattini ◽  
Christian Teutloff ◽  
Joshua F. Alfaro ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Aldehyde Oxidase ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
The Impact

scholarly journals Progressive effects of single-nucleotide polymorphisms on 16 phenotypic traits based on longitudinal data

2020 ◽  
Vol 42 (4) ◽  
pp. 393-403
Author(s):  
Donghe Li ◽  
Hahn Kang ◽  
Sanghun Lee ◽  
Sungho Won
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Longitudinal Data ◽  
Density Lipoprotein ◽  
Phenotypic Traits ◽  
Chromosome 2 ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Longitudinal Changes ◽  
Genome Wide ◽  
A Genome

Abstract Background There are many research studies have estimated the heritability of phenotypic traits, but few have considered longitudinal changes in several phenotypic traits together. Objective To evaluate the progressive effect of single nucleotide polymorphisms (SNPs) on prominent health-related phenotypic traits by determining SNP-based heritability ($$h_{snp}^{2}$$hsnp2) using longitudinal data. Methods Sixteen phenotypic traits associated with major health indices were observed biennially for 6843 individuals with 10-year follow-up in a Korean community-based cohort. Average SNP heritability and longitudinal changes in the total period were estimated using a two-stage model. Average and periodic differences for each subject were considered responses to estimate SNP heritability. Furthermore, a genome-wide association study (GWAS) was performed for significant SNPs. Results Each SNP heritability for the phenotypic mean of all sixteen traits through 6 periods (baseline and five follow-ups) were significant. Gradually, the forced vital capacity in one second (FEV1) reflected the only significant SNP heritability among longitudinal changes at a false discovery rate (FDR)-adjusted 0.05 significance level ($$h_{snp}^{2} = 0.171$$hsnp2=0.171, FDR = 0.0012). On estimating chromosomal heritability, chromosome 2 displayed the highest heritability upon periodic changes in FEV1. SNPs including rs2272402 and rs7209788 displayed a genome-wide significant association with longitudinal changes in FEV1 (P = 1.22 × 10−8 for rs2272402 and P = 3.36 × 10−7 for rs7209788). De novo variants including rs4922117 (near LPL, P = 2.13 × 10−15) of log-transformed high-density lipoprotein (HDL) ratios and rs2335418 (near HMGCR, P = 3.2 $$\times$$× 10−9) of low-density lipoprotein were detected on GWAS. Conclusion Significant genetic effects on longitudinal changes in FEV1 among the middle-aged general population and chromosome 2 account for most of the genetic variance.

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