Myristoylation of human immunodeficiency virus type 1 gag protein is required for efficient env protein transportation to the surface of cells

Highly conserved amino acids in the N-terminal region of the human immunode ficiency virus type 1 (HIV-1) pr55(gag), recognized to be critical for the attachment of myristic acid. We previously reported that the env protein wa s not detected on the cell surface by blocking of N-myristoylation of Pr55( gag) with N-myristoyl glycinal diethylacetal. Here, we constructed a mutant by substituting the N-terminal glycine of Pr55(gag) with alanine to demons trate that N-myristoylation of Pr55(gag) is required far efficient env prot ein transportation to the cell surface. The expression level of the env pro tein on the surface of Jurkat cells transfected with the myristoylation-def ective phenotype was observed to be significantly reduced by electron micro scopic analyses with a gold-labeled monoclonal antibody against the env pro tein. In addition, Jurkat cells transfected with the myristoylation-defecti ve phenotype lost the ability of envelope-mediated cell-to-cell fusion, The results suggest that N-myristoylation of the HIV-1 gag protein is necessar y for efficient env protein transportation to the cell surface. (C) 2001 Ac ademic Press.