Actin-binding cellular proteins inside human immunodeficiency virus type 1

Host proteins are incorporated both on and inside human immunodeficiency vi rus type 1 (HIV-1) virions. To identify cellular proteins inside HIV-1, vir ion preparations were treated by a protease-digestion technique that remove s external host proteins, allowing for the study of the proteins inside the virus. Treated HIV-1 preparations were analyzed by immunoblot, high-pressu re liquid chromatography, and protein sequence analyses. These analyses ide ntified several cellular proteins inside HIV-1: elongation factor 1 alpha, glyceraldehyde-3-phosphate dehydrogenase, HS-1, phosphatidylethanolamine-bi nding protein, Pin1, Lck, Nm23-H1, and the C-terminal tail of CD43. Several of these proteins were found as fragments of their full-sized proteins tha t appear to be generated by our protease treatment of the virions, the HIV- 1 protease, or a cellular protease. Recent advances in cell biology and bio chemistry have identified some of these proteins as actin-binding proteins. These results support the hypothesis that actin filaments are incorporated into the virion and may provide additional clues for the understanding of the interaction between viral and cellular proteins during assembly and bud ding. (C) 2000 Academic Press.