title: Nef-induced major histocompatibility complex class I down-regulation is functionally dissociated from its virion incorporation, enhancement of viral infectivity, and CD4 down-regulation.
abstract: The N-terminal alpha-helix domain of the human immunodeficiency virus type 1 (HIV-1) Nef protein plays important roles in enhancement of viral infectivity, virion incorporation of Nef, and the down-regulation of major histocompatibility complex class I (MHC-I) expression on cell surfaces. In this study, we demonstrated that Met 20 in the alpha-helix domain was indispensable for the ability of Nef to modulate MHC-I expression but not for other events. We also showed that Met 20 was unnecessary for the down-regulation of CD4. These findings indicate that the region governing MHC-I down-regulation is proximate in the alpha-helix domain but is dissociated functionally from that determining enhancement of viral infectivity, virion incorporation of Nef, and CD4 down-regulation.
authors.affiliation: Department of Virology, The University of Tokushima School of Medicine, Tokushima, Tokushima 770-8503, Japan. akari@basic.med.tokushima-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Akari
authors.forename: S
authors.initials: S
authors.lastname: Arold
authors.forename: T
authors.initials: T
authors.lastname: Fukumori
authors.forename: T
authors.initials: T
authors.lastname: Okazaki
authors.forename: K
authors.initials: K
authors.lastname: Strebel
authors.forename: A
authors.initials: A
authors.lastname: Adachi
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015704:CD4 Antigens / Q000096:biosynthesis*; D002478:Cells, Cultured; D015536:Down-Regulation; D015693:Gene Products, nef / Q000235:genetics / Q000378:metabolism*; D005805:Genes, MHC Class I; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000821:virology; D008715:Methionine / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D014771:Virion; D054311:nef Gene Products, Human Immunodeficiency Virus
chemical_list: D015704:CD4 Antigens; D015693:Gene Products, nef; D054311:nef Gene Products, Human Immunodeficiency Virus; D008715:Methionine