What does S-palmitoylation do to membrane proteins?

Abstract

S-palmitoylation is post-translational modification, which consists in the addition of a C16 acyl chain to cytosolic cysteines and which is unique amongst lipid modifications in that it is reversible. It can thus, like phosphorylation or ubiquitination, act as a switch. While palmitoylation of soluble proteins allows them to interact with membranes, the consequences of palmitoylation for transmembrane proteins are more enigmatic. We briefly review the current knowledge regarding the enzymes responsible for palmitate addition and removal. We then describe various observed consequences of membrane protein palmitoylation. We propose that the direct effects of palmitoylation on transmembrane proteins, however, might be limited to four non-mutually exclusive mechanistic consequences: alterations in the conformation of transmembrane domains, association with specific membrane domains, controlled interactions with other proteins and controlled interplay with other post-translational modifications. S-palmitoylation is the reversible addition of a C16 acyl chain to cysteines. With a focus of transmembrane proteins, we review the current understanding of this modification and its reported consequences. Many of these are, however, likely to be secondary effects. Four non-mutually exclusive mechanistic consequences of palmitoylation have recently emerged and are discussed. © 2013 The Authors Journal compilation © 2013 FEBS.