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Multifaceted interactions between lentiviral Vif and host molecules for viral infectivity enhancement

慢病毒 Vif 与宿主分子之间的多方面相互作用增强病毒感染力

基本信息

批准号：
10640135
负责人：
Yong Xiong
金额：
$ 47.83万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-06-15 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10640135
关键词：
3-Dimensional Binding Biochemical Biophysics CD4 Positive T Lymphocytes Capsid Proteins Cell Cycle Arrest Classification Communities Comparative Study Complex Cryoelectron Microscopy Cyclophilin A Cytidine Deaminase Deamination Degradation Pathway Evolution Fluorescence Goals HIV HIV-1 Host Defense Mechanism Immune Immune system In Vitro Infection Integration Host Factors Invaded Knowledge Mammals Mediating Methods Molecular Mutagenesis PPP2R5A gene Pathway interactions Peptidylprolyl Isomerase Primate Lentiviruses Protein Family Protein Isoforms Protein phosphatase Proteins Research Research Design Research Project Grants Resolution Reverse Transcription Sheep Spectrum Analysis Structure System Techniques Therapeutic Transcript Ubiquitin Validation Viral Viral Physiology Viral Proteins Virion Virus Diseases Virus Inhibitors Virus Replication Visna-maedi virus Work X-Ray Crystallography cellular targeting cofactor combat design experimental study factor A in vivo inhibitor insight multicatalytic endopeptidase complex novel therapeutics pathogen reconstruction recruit structural biology tool transcription factor ubiquitin-protein ligase

项目摘要

PROJECT DESCRIPTION The APOBEC3 (A3) family of proteins are cellular cytidine deaminases that suppress human immunodeficiency virus type 1 (HIV-1) infection by hypermutation of viral reverse transcripts and physically blocking reverse transcription. To evade this host defense mechanism, HIV-1 expresses the virion infectivity factor (Vif), which hijacks a cellular E3 ubiquitin ligase complex and targets A3 proteins (A3F/G/H/D) for proteasome-mediated degradation. Besides degrading A3s, HIV-1 Vif also causes G2 cell cycle arrest by targeting multiple protein phosphatase 2A (PP2A) regulators (PPP2R5 proteins) for degradation. Adding to the complexity of Vif-host protein interactions, HIV-1 Vif utilizes the transcription factor CBFβ as a non-canonical cofactor, while maedi-visna virus (MVV) Vif co-opts the prolyl isomerase cyclophilin A (CypA) instead. Our goal is to establish the biochemical and structural principles for the multifaceted activities of lentiviral Vif molecules that recruit cellular factors to degrade host proteins via ubiquitin-proteasome pathways. To achieve our goal, we will use a combination of biochemical, biophysical, structural biology, and cellular functional techniques. To establish the mechanisms by which A3 proteins are targeted by the HIV-1 Vif (Aim1), we will determine high- resolution structures of the A3-Vif-E3 interaction complexes, validate these structures by structure-guided mutagenesis experiments in vitro and in vivo, and interrogate the molecular determinants of Vif/A3/E3 ligase assembly and activation. In addition, we will also study the degradation-independent mode of Vif inhibition of A3 deamination and antiviral activities. To better understand CypA-mediated formation of MVV Vif-E3 ubiquitin ligase (Aim2), we will assemble MVV Vif/CypA/E3 ligase complexes with or without A3 substrates, determine their high-resolution structures, and perform biochemical and functional validations of our structural observations. The influences of capsid proteins on the assembly and activation of MVV Vif-E3 ligase will also be investigated. To delineate the mechanisms of PPP2R5/PP2A recruitment by lentiviral Vif-E3 ubiquitin ligases (Aim3), we will investigate the effects of PPP2R5 proteins on the assemblies of the CBFβ-mediated HIV-1 Vif and CypA-mediated MVV Vif-E3 ligases, obtain high-resolution structures, and perform structure- guided validations. Our comprehensive research design provides a robust approach that will generate unprecedented insights into the diverse functions of lentiviral Vif molecules.

项目描述