Journal Article

A combined EM and proteomic analysis places HIV-1 Vpu at the crossroads of retromer and ESCRT complexes: PTPN23 is a Vpu-cofactor

Gonzalez, David J., Guatelli, John, Stoneham, Charlotte A., Thor, Andrea, Lapek, John, Ellisman, Mark, Pache, Lars, Chanda, Sumit K., Deerinck, Thomas, Wozniak, Jacob M., Langer, Simon, De Jesus, Paul D.

2021

Overview

The HIV-1 accessory protein Vpu modulates membrane protein trafficking and degradation to provide evasion of immune surveillance. Targets of Vpu include CD4, HLAs, and BST-2. Several cellular pathways co-opted by Vpu have been identified, but the picture of Vpu’s itinerary and activities within membrane systems remains incomplete. Here, we used fusion proteins of Vpu and the enzyme ascorbate peroxidase (APEX2) to compare the ultrastructural locations and the proximal proteomes of wild type Vpu and Vpu-mutants. The proximity-omes of the proteins correlated with their ultrastructural locations and placed wild type Vpu near both retromer and ESCRT-0 complexes. Hierarchical clustering of protein abundances across the mutants was essential to interpreting the data and identified Vpu degradation-targets including CD4, HLA-C, and SEC12 as well as Vpu-cofactors including HGS, STAM, clathrin, and PTPN23, an ALIX-like protein. The Vpu-directed degradation of BST-2 was supported by STAM and PTPN23 and to a much lesser extent by the retromer subunits Vps35 and SNX3. PTPN23 also supported the Vpu-directed decrease in CD4 at the cell surface. These data suggest that Vpu directs targets from sorting endosomes to degradation at multi-vesicular bodies via ESCRT-0 and PTPN23.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Analysis / Ascorbic acid / Biology and Life Sciences / CD4 antigen / Cell surface / Clathrin / Cluster analysis / Clustering / Cofactors / Degradation / Development and progression / Endosomal Sorting Complexes Required for Transport - genetics / Endosomal Sorting Complexes Required for Transport - metabolism / Endosomes / Enzymes / Flow cytometry / Health aspects / HeLa Cells / Histocompatibility antigen HLA / HIV / HIV infection / HIV Infections - genetics / HIV Infections - metabolism / HIV Infections - virology / HIV-1 - physiology / Human immunodeficiency virus / Human Immunodeficiency Virus Proteins - genetics / Human Immunodeficiency Virus Proteins - metabolism / Humans / Immunosurveillance / L-Ascorbate peroxidase / Localization / Membrane proteins / Membrane trafficking / Membranes / Microscopy, Electron / Mutants / Mutation / Peroxidase / Physiological aspects / Protein Interaction Domains and Motifs / Protein Multimerization / Protein Transport / Protein Tyrosine Phosphatases, Non-Receptor - genetics / Protein Tyrosine Phosphatases, Non-Receptor - metabolism / Proteins / Proteome - analysis / Proteome - metabolism / Proteomes / Proteomics / Research and Analysis Methods / Sorting Nexins - chemistry / Sorting Nexins - genetics / Sorting Nexins - metabolism / Stains & staining / Transmission electron microscopy / Vesicular Transport Proteins - chemistry / Vesicular Transport Proteins - genetics / Vesicular Transport Proteins - metabolism / Viral proteins / Viral Regulatory and Accessory Proteins - genetics / Viral Regulatory and Accessory Proteins - metabolism / Viroporin Proteins - genetics / Viroporin Proteins - metabolism