Identification of CKAP4/p63 as a major substrate of the palmitoyl acyltransferase DHHC2, a putative tumor suppressor, using a novel proteomics method.

Protein palmitoylation is the post-translational addition of the 16-carbon fatty acid palmitate to specific cysteine residues by a labile thioester linkage. Palmitoylation is mediated by a family of at least 23 palmitoyl acyltransferases (PATs) characterized by an Asp-His-His-Cys (DHHC) motif. Many palmitoylated proteins have been identified, but PAT-substrate relationships are mostly unknown. Here we present a method called palmitoyl-cysteine isolation capture and analysis (or PICA) to identify PAT-substrate relationships in a living vertebrate system and demonstrate its effectiveness by identifying CKAP4/p63 as a substrate of DHHC2, a putative tumor suppressor.