The NH2-terminal domain of the human T-cell leukemia virus type 1 capsid protein is involved in particle formation.
The human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type 1 (HTLV-1) capsid proteins (CA) display similar structures formed by two independently folded N-terminal (NTD) and C-terminal (CTD) domains. To characterize the functions harbored by the HTLV-1 CA domains in particle formation, 12 sites scattered throughout the protein were mutated. The effects of the mutations on Gag membrane binding, proteolytic processing, and virus-like particle secretion were analyzed. It appears that the NTD is the major partner of indirect or direct Gag-Gag interactions. In particular, most of the NTD mutations impaired virion morphogenesis, and no mutation located in the NTD could be fully rescued by coexpression of wild-type Gag. In contrast, the CTD seems not to be involved in Gag-Gag interactions. Nevertheless, an unknown function required for particle formation is located in the CTD. Thus, despite an overall structural similarity between the HIV-1 and HTLV-1 CA proteins, their NTDs and CTDs exhibit different functions.
Rayne
F
F
INSERM U443, Equipe Rétrovirus et Transfert Génique, Université Victor Segalen Bordeaux 2, F-33076 Bordeaux Cedex, France.
Bouamr
F
F
Lalanne
J
J
Mamoun
R Z
RZ
D000595:Amino Acid Sequence; D002213:Capsid / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism; D016679:Genome, Viral; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D019065:Virus Assembly
D015683:Gene Products, gag