The Conserved Core of Human Immunodeficiency Virus Type 1 Nef Is Essential for Association with Lck and for Enhanced Viral Replication in T-Lymphocytes

• Published in: Virology (New York, N.Y.) N.Y.), 1999-11, Vol.264 (1), p.5-15
• Main Authors: Cheng, Hua, Hoxie, James, Parks, Wade P.
• Format: Article
• Language: English
• Subjects: Base Sequence; Cell Line; Conserved Sequence; Fyn protein; Gene Products, nef - genetics; Gene Products, nef - metabolism; Genes, nef; Hck protein; HIV-1 - genetics; HIV-1 - physiology; human immunodeficiency virus 1; Humans; Lck protein; Lymphocyte Specific Protein Tyrosine Kinase p56(lck) - metabolism; Lyn protein; Mutagenesis, Site-Directed; nef Gene Products, Human Immunodeficiency Virus; Nef protein; Recombinant Proteins - metabolism; Sequence Deletion; simian immunodeficiency virus; Simian Immunodeficiency Virus - genetics; Simian Immunodeficiency Virus - physiology; Src protein; src-Family Kinases - metabolism; T-Lymphocytes - physiology; T-Lymphocytes - virology; Transfection; Virus Replication - genetics
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1006/viro.1999.9937

The Nef protein of the primate lentiviruses, including human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV), is a myristylated protein associated with increased viral replication and enhanced pathogenicity. Both the potentiation of T-lymphocyte activation and the enhanced serine-phosphorylation of HIV-1 capsid by Nef correlate with increased viral replication. We report the functional interactions of the Nef proteins with Src kinases. The Nef proteins from HIV-1 and SIV bind to Lck as well as Hck, Lyn, and Fyn. The SH3 and SH2 domains of Lck are sufficient for coprecipitation with non-tyrosine-phosphorylated Nef proteins. The conserved core region of HIV-1 Nef is essential for the interaction with Lck and is also important for enhanced HIV-1 replication in T-lymphocytes. In addition, we show that SIV and HIV-1 Nef proteins are differentially tyrosine-phosphorylated. The kinase-active Lck tyrosine-phosphorylates SIVmac239 Nef but does not phosphorylate HIV-1 Nef. These data suggest that the association of Nef and Lck is central to the enhanced viral replication of HIV-1 and SIV in T-lymphocytes.