title: Cellular motor protein KIF-4 associates with retroviral Gag.
abstract: Previously we demonstrated that murine retroviral Gag proteins associate with a cellular motor protein, KIF-4. Using the yeast two-hybrid assay, we also found an association of KIF-4 with Gag proteins of Mason-Pfizer monkey virus (MPMV), simian immunodeficiency virus (SIV), and human immunodeficiency virus type 1 (HIV-1). Studies performed with mammalian cell systems confirmed that the HIV-1 Gag protein associates with KIF-4. Soluble cytoplasmic proteins from cells infected with recombinant vaccinia virus expressing the entire Gag-Pol precursor protein of HIV-1 or transfected with HIV-1 molecular clone pNL4-3 were fractionated by sucrose gradient centrifugation and further separated by size-exclusion and anion-exchange chromatographies. KIF-4 and HIV-1 Gag cofractionated in both chromatographic separations. Immunoprecipitation assays have also verified the KIF-4-Gag association. KIF-4 binds mainly to the Gag precursor (Pr55 Gag) and a matrix-capsid processing intermediate (Pr42) but not to other processed Gag products. The binding of Gag is mediated by a domain of KIF-4 proximal to the C terminus. These results, and our previous studies, raise the possibility that KIF-4 may play an important role in retrovirus Gag protein transport.
authors.affiliation: Laboratory of Immunopathology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Tang
authors.forename: U
authors.initials: U
authors.lastname: Winkler
authors.forename: E O
authors.initials: EO
authors.lastname: Freed
authors.forename: T A
authors.initials: TA
authors.lastname: Torrey
authors.forename: W
authors.initials: W
authors.lastname: Kim
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: S P
authors.initials: SP
authors.lastname: Goff
authors.forename: H C
authors.initials: HC
authors.lastname: Morse
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D016093:Mason-Pfizer monkey virus; D011233:Precipitin Tests; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012190:Retroviridae / Q000378:metabolism*; D015302:Simian Immunodeficiency Virus
chemical_list: D015683:Gene Products, gag; D011993:Recombinant Fusion Proteins; D016547:Kinesins