Myristoylation of seven different a subunits of guanine nucleotide-binding regulatory proteins (G proteins) was examined by expressing these proteins in monkey kidney COS cells. Metabolic labeling studies of cells transfected with cytomegalovirus-based expression vectors indicated that [3H]myristate was incorporated into αi2, αi2, αi3, α0, αt, and αz, but not αs subunits. The role of myristoylation in the association of α subunits with membranes was analyzed by site-directed mutagenesis and by substitution of myristate with a less hydrophobic analog, 10-(propoxy)decanoate (11-oxamyristate). Myristoylation of α0 was blocked when an alanine residue was substituted for its amino-terminal glycine, as was association of the protein with membranes. Substitution of the myristoyl group with 11-oxamyristate affected the cellular distribution of a subset of acylated a subunits. The results are consistent with a model wherein the hydrophobic interaction of myristate with the bilayer permits continued association of the protein with the plasma membrane when G-protein α subunits dissociate from βγ.
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Jan 1 1990|
- Fatty acid analog
- Protein N-myristoylation