The HIV-1 Gag precursor Pr55 gag synthesized in yeast is myristoylated and targeted to the plasma membrane

Abstract

Myristoylation of the Pr65 gag protein from Moloney murine leukemia virus has been shown to be essential for virus particle formation [Rein et al., Proc. Natl. Acad. Sci. USA 83 (1986) 7246–7250], and by analogy, myristoylation of the human immunodeficiency virus (HIV) Gag precursor could possibly play a similar role. We have investigated the expression and myristoylation of the complete HIV Gag precursor Pr55 gag in yeast, the subcellular localization of that protein, and the contribution of the myristoyl-glycine residue to this localization. Immunogold labelling of myristoylated Pr55 gag with antibodies directed against HIV Gag products was apparent in the vicinity of the plasma membrane. On the contrary, non-myristoylated derivatives of Pr55 gag were only detected in relatively well-defined regions of the cytoplasm. These results show that targeting and accumulation of the HIV Gag precursor, Pr55 gag, at the plasma membrane occurs in yeast in the absence of other viral components and requires the N-myristoyl-glycine residue.