Human immunodeficiency virus type 1 Nef associateswith a cellular serine kinase in T lymphocytes.

With T-cell lines constitutively expressing Neffrom the SF2 strain of human immunodeficiency virus type 1 (HIV-1SF2) in theform of a hybrid CD8-Nef fusion protein or T-cell lines chronically infectedwith HIV-1SF2, a cellular serine kinase was found that specifically associateswith Nef. Proteins of 62 kDa and 72 kDa, which coimmunoprecipitated with Nef,were phosphorylated in in vitro kinase assays. This Nef-associated serine kinaseactivity was not blocked by inhibitors of protein kinase C or protein kinase Aand was lost when Nef was truncated at amino acid 94 or 99. These findingspresent evidence that a serine kinase activity is associated with Nef expressedin human T lymphocytes.