Geranylgeranylation

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Geranylgeranylation is a form of prenylation, which is a post-translational modification of proteins that involves the attachment of one or two 20-carbon lipophilic geranylgeranyl isoprene units from geranylgeranyl diphosphate to one or two cysteine residue(s) at the C-terminus of specific proteins. Prenylation (including geranylgeranylation) is thought to function, at least in part, as a membrane anchor for proteins.[1]

The process of geranylgeranylation can be catalyzed by either geranylgeranyl transferase I (GGTase I) or Rab GGTase (also GGTase II). GGTase I catalyzes the addition of one geranylgeranyl group onto the C-terminal consensus sequence CAAL (somewhat similar to farnesyltransferase reactions), where C=cysteine, A=any aliphatic amino acid, and L=leucine. Rab GGTase adds a total of two geranylgeranyl groups onto two cysteine residues at the C-terminal consensus sequence CXC or XXCC. The source of the geranylgeranyl group is geranylgeranyl diphosphate, which is synthesized by GGPS1 within the isoprenoid biosynthetic pathway.[2]

An example of this can be seen in the lipid anchoring of the Rho GTPase family of signaling molecules and the gamma subunit of heterotrimeric G proteins.

References[edit]

  1. ^ Jiang, Yu; Proteau, Philip; Poulter, Dale; Ferro-Novick, Susan (September 15, 1995). "BTS1 Encodes a Geranylgeranyl Diphosphate Synthase in Saccharomyces cerevisiae", The Journal of Biological Chemistry, 270, 21793-21799
  2. ^ Wiemer, AJ; Hohl, RJ; Wiemer, DF (June 2009). "The intermediate enzymes of isoprenoid metabolism as anticancer targets.". Anti-cancer agents in medicinal chemistry 9 (5): 526–42. PMID 19519294.