title: HIV-1 matrix protein binding to RNA.
abstract: The matrix (MA) domain of the human immunodeficiency virus type 1 (HIV-1) precursor Gag (PrGag) protein plays multiple roles in the viral replication cycle. One essential role is to target PrGag proteins to their lipid raft-associated phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P(2)] assembly sites at the plasma membranes of infected cells. In addition to this role, several reports have implicated nucleic acid binding properties to retroviral MAs. Evidence indicates that RNA binding enhances the binding specificity of MA to PI(4,5)P(2)-containing membranes and supports a hypothesis in which RNA binding to MA acts as a chaperone that protects MA from associating with inappropriate cellular membranes prior to PrGag delivery to plasma membrane assembly sites. To gain a better understanding of HIV-1 MA-RNA interactions, we have analyzed the interaction of HIV MA with RNA ligands that were selected previously for their high affinities to MA. Binding interactions were characterized via bead binding, fluorescence anisotropy, gel shift, and analytical ultracentrifugation methods. Moreover, MA residues that are involved in RNA binding were identified from NMR chemical shift data. Our results indicate that the MA RNA and PI(4,5)P(2) binding sites overlap and suggest models for Gag-membrane and Gag-RNA interactions and for the HIV assembly pathway.
authors.affiliation: Vollum Institute and Department of Microbiology, Oregon Health and Science University, Portland, OR 97201-3098, USA. alfadhli@ohsu.edu
authors.forename: Ayna
authors.initials: A
authors.lastname: Alfadhli
authors.forename: Henry
authors.initials: H
authors.lastname: McNett
authors.forename: Seyram
authors.initials: S
authors.lastname: Tsagli
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Bächinger
authors.forename: David H
authors.initials: DH
authors.lastname: Peyton
authors.forename: Eric
authors.initials: E
authors.lastname: Barklis
mesh_terms: D016880:Anisotropy; D001665:Binding Sites; D001667:Binding, Competitive; D024202:Electrophoretic Mobility Shift Assay; D005453:Fluorescence; D015497:HIV-1 / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D011485:Protein Binding; D012367:RNA, Viral / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000378:metabolism*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000378:metabolism*
chemical_list: D012367:RNA, Viral; D014763:Viral Matrix Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus