Hydrolyzes fatty acids from S-acylated cysteine residues in proteins with a strong preference for palmitoylated G-alpha proteins over other acyl substrates. Mediates the deacylation of G-alpha proteins such as GPA1 in vivo, but has weak or no activity toward palmitoylated Ras proteins. Has weak lysophospholipase activity in vitro; however such activity may not exist in vivo