DHHC9 and GCP16 constitute a human protein fatty acyltransferase with specificity for H- and N-Ras.
Covalent lipid modifications mediate the membrane attachment and biological activity of Ras proteins. All Ras isoforms are farnesylated and carboxyl-methylated at the terminal cysteine; H-Ras and N-Ras are further modified by palmitoylation. Yeast Ras is palmitoylated by the DHHC cysteine-rich domain-containing protein Erf2 in a complex with Erf4. Here we report that H- and N-Ras are palmitoylated by a human protein palmitoyltransferase encoded by the ZDHHC9 and GCP16 genes. DHHC9 is an integral membrane protein that contains a DHHC cysteine-rich domain. GCP16 encodes a Golgi-localized membrane protein that has limited sequence similarity to yeast Erf4. DHHC9 and GCP16 co-distribute in the Golgi apparatus, a location consistent with the site of mammalian Ras palmitoylation in vivo. Like yeast Erf2.Erf4, DHHC9 and GCP16 form a protein complex, and DHHC9 requires GCP16 for protein fatty acyltransferase activity and protein stability. Purified DHHC9.GCP16 exhibits substrate specificity, palmitoylating H- and N-Ras but not myristoylated G (alphai1) or GAP-43, proteins with N-terminal palmitoylation motifs. Hence, DHHC9.GCP16 displays the properties of a functional human ortholog of the yeast Ras palmitoyltransferase.
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
John T
JT
Swarthout
Sandra
S
Lobo
Lynn
L
Farh
Monica R
MR
Croke
Wendy K
WK
Greentree
Robert J
RJ
Deschenes
Maurine E
ME
Linder
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D011905:Genes, ras; D000077614:Golgi Matrix Proteins; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity; D014018:Tissue Distribution; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
C480862:GOLGA7 protein, human; D000077614:Golgi Matrix Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D000217:Acyltransferases; C504825:ZDHHC9 protein, human; D018631:ras Proteins