Background: The human APOBEC3G (A3G) protein activity is associated with innate immunity against HIV-1 by inducing high rates of guanosines to adenosines (G-to-A) mutations (viz., hypermutation) in the viral DNA. If hypermutation is not enough to disrupt the reading frames of viral genes, it may likely increase the HIV-1 diversity. To counteract host innate immunity HIV-1 encodes the Vif protein that binds A3G protein and form complexes to be degraded by cellular proteolysis.
Methods: Here we studied the pattern of substitutions in the vif gene and its association with clinical status of HIV-1 infected individuals. To perform the study, unique vif gene sequences were generated from 400 antiretroviral-naïve individuals.
Results: The codon pairs: 78-154, 85-154, 101-157, 105-157, and 105-176 of vif gene were associated with CD4+ T cell count lower than 500 cells per mm(3). Some of these codons were located in the (81)LGQGVSIEW(89) region and within the BC-Box. We also identified codons under positive selection clustered in the N-terminal region of Vif protein, between (21)WKSLVK(26) and (40)YRHHY(44) regions (i.e., 31, 33, 37, 39), within the BC-Box (i.e., 155, 159) and the Cullin5-Box (i.e., 168) of vif gene. All these regions are involved in the Vif-induced degradation of A3G/F complexes and the N-terminal of Vif protein binds to viral and cellular RNA.
Conclusions: Adaptive evolution of vif gene was mostly to optimize viral RNA binding and A3G/F recognition. Additionally, since there is not a fully resolved structure of the Vif protein, codon pairs associated with CD4+ T cell count may elucidate key regions that interact with host cell factors. Here we identified and discriminated codons under positive selection and codons under functional constraint in the vif gene of HIV-1.
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http://dx.doi.org/10.1186/1471-2334-13-173 | DOI Listing |
Introduction: HIV-1 non-structural proteins are promising targets for vaccine development and for creating approaches to personalized medicine. HIV-1 sub-subtype A6 has become the dominating strain in Russia. However, the geographic, economic and demographic characteristics of the country can contribute to the formation of differences between A6 variants circulating in different regions.
View Article and Find Full Text PDFFront Immunol
November 2024
Department of Immunology, Center for Innate Immunity and Immune Disease, School of Medicine, University of Washington, Seattle, WA, United States.
BMC Infect Dis
September 2024
Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
Background: HIV-1 has well-established mechanisms to disrupt essential pathways in people with HIV, such as inflammation and metabolism. Moreover, diversity of the amino acid sequences in fundamental HIV-1 proteins including Tat and Vif, have been linked to dysregulating these pathways, and subsequently influencing clinical outcomes in people with HIV. However, the relationship between Tat and Vif amino acid sequence variation and specific immune markers and metabolites of the tryptophan-kynurenine (Trp-Kyn) pathway remains unclear.
View Article and Find Full Text PDFArch Toxicol
December 2024
Developmental and Reproductive Toxicology Research Group, Korea Institute of Toxicology, Daejeon, 34114, Republic of Korea.
Bioorg Med Chem Lett
October 2024
State Key Laboratory of Biotherapy, Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Sichuan, Chengdu 610041, China. Electronic address:
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