title: The HIV-1 matrix domain of Gag is required for Vpu responsiveness during particle release.
abstract: HIV-1 viral protein U (Vpu) facilitates virus particle release. To determine whether Gag is sufficient for generation of a target for Vpu-mediated particle release, we expressed HIV-1 Gag protein in the absence of the other viral genes. The resulting particles were still Vpu responsive. Mutational analysis of Gag indicated that the matrix domain (MA) is required for Vpu responsiveness. However, additional mutations in other domains of Gag, which affect the formation of stable virus particles, also abrogate Vpu responsiveness on total Gag release. Coexpression of the wild-type gag gene and a gag mutant lacking the MA domain renders the MA- mutant Vpu responsive. This indicates that Gag molecules lacking MA are still incorporated into particles through association with wild-type Gag molecules and that the resulting composite particles are sufficient for Vpu-mediated exit.
authors.affiliation: McArdle Laboratory for Cancer Research, University of Wisconsin Medical School, 1400 University Avenue, Madison, Wisconsin 53706, USA.
authors.forename: Y H
authors.initials: YH
authors.lastname: Lee
authors.forename: M D
authors.initials: MD
authors.lastname: Schwartz
authors.forename: A T
authors.initials: AT
authors.lastname: Panganiban
mesh_terms: D001665:Binding Sites; D017353:Gene Deletion; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology*; D006367:HeLa Cells; D054298:Human Immunodeficiency Virus Proteins; D006801:Humans; D011485:Protein Binding; D014764:Viral Proteins / Q000378:metabolism; D054334:Viral Regulatory and Accessory Proteins / Q000378:metabolism*; D014771:Virion / Q000502:physiology; D014779:Virus Replication / Q000502:physiology*; D000086082:Viroporin Proteins
chemical_list: D015683:Gene Products, gag; D054298:Human Immunodeficiency Virus Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C514859:vpu protein, Human immunodeficiency virus 1; D000086082:Viroporin Proteins