title: HIV signaling through CD4 and CCR5 activates Rho family GTPases that are required for optimal infection of primary CD4+ T cells.
abstract: HIV-1 hijacks host cell machinery to ensure successful replication, including cytoskeletal components for intracellular trafficking, nucleoproteins for pre-integration complex import, and the ESCRT pathway for assembly and budding. It is widely appreciated that cellular post-translational modifications (PTMs) regulate protein activity within cells; however, little is known about how PTMs influence HIV replication. Previously, we reported that blocking deacetylation of tubulin using histone deacetylase inhibitors promoted the kinetics and efficiency of early post-entry viral events. To uncover additional PTMs that modulate entry and early post-entry stages in HIV infection, we employed a flow cytometric approach to assess a panel of small molecule inhibitors on viral fusion and LTR promoter-driven gene expression.
  
  
  
  While viral fusion was not significantly affected, early post-entry viral events were modulated by drugs targeting multiple processes including histone deacetylation, methylation, and bromodomain inhibition. Most notably, we observed that inhibitors of the Rho GTPase family of cytoskeletal regulators-including RhoA, Cdc42, and Rho-associated kinase signaling pathways-significantly reduced viral infection. Using phosphoproteomics and a biochemical GTPase activation assay, we found that virion-induced signaling via CD4 and CCR5 activated Rho family GTPases including Rac1 and Cdc42 and led to widespread modification of GTPase signaling-associated factors.
  
  
  
  Together, these data demonstrate that HIV signaling activates members of the Rho GTPase family of cytoskeletal regulators that are required for optimal HIV infection of primary CD4+ T cells.
authors.affiliation: Division of Infectious Diseases, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA.
authors.forename: Mark B
authors.initials: MB
authors.lastname: Lucera
authors.affiliation: Department of Nutrition, Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, 10900 Euclid Ave, BRB 919, Cleveland, OH, 44106, USA.
authors.forename: Zach
authors.initials: Z
authors.lastname: Fleissner
authors.affiliation: Department of Nutrition, Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, 10900 Euclid Ave, BRB 919, Cleveland, OH, 44106, USA.
authors.forename: Caroline O
authors.initials: CO
authors.lastname: Tabler
authors.affiliation: Department of Nutrition, Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, 10900 Euclid Ave, BRB 919, Cleveland, OH, 44106, USA.
authors.forename: Daniela M
authors.initials: DM
authors.lastname: Schlatzer
authors.affiliation: Department of Nutrition, Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, 10900 Euclid Ave, BRB 919, Cleveland, OH, 44106, USA.
authors.forename: Zach
authors.initials: Z
authors.lastname: Troyer
authors.affiliation: Department of Nutrition, Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, 10900 Euclid Ave, BRB 919, Cleveland, OH, 44106, USA. jct63@case.edu.
authors.forename: John C
authors.identifier: 0000-0002-4218-5870
authors.initials: JC
authors.lastname: Tilton
mesh_terms: D015704:CD4 Antigens / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000821:virology*; D002478:Cells, Cultured; D006678:HIV / Q000502:physiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D019713:Receptors, CCR5 / Q000378:metabolism*; D015398:Signal Transduction; D016662:Virus Integration; D053586:Virus Internalization; D020741:rho GTP-Binding Proteins / Q000378:metabolism*
chemical_list: C584933:CCR5 protein, human; D015704:CD4 Antigens; D019713:Receptors, CCR5; D020741:rho GTP-Binding Proteins
keywords: Cdc42; HIV-1; ROCK; Rho GTPases; Small molecule screen; Viral infection