geranylgeranylotransferaz

Geranylgeranyltransferase, often abbreviated as GGTase, is a family of enzymes that catalyze the transfer of a geranylgeranyl group from a donor molecule, typically geranylgeranyl pyrophosphate (GGPP), to a target protein. This process is known as geranylgeranylation, a type of prenylation. Geranylgeranylation is a crucial post-translational modification that plays a significant role in protein function and localization.

There are two main types of geranylgeranyltransferases: protein geranylgeranyltransferase type I (PGGT1) and protein geranylgeranyltransferase type II (PGGT2). PGGT1 is involved in the modification of proteins containing a C-terminal CaaX motif, where 'C' represents cysteine, 'a' represents an aliphatic amino acid, and 'X' is a variable amino acid. This modification often targets proteins to cellular membranes, influencing their signaling capabilities and interactions. PGGT2, on the other hand, targets proteins with a distinct C-terminal motif and is involved in the prenylation of small GTPases, which are key regulators of cellular processes such as cell growth, differentiation, and intracellular transport.

The geranylgeranylation reaction is vital for the proper functioning of many cellular pathways. Aberrations in GGTase activity have been linked to various diseases, including cancer and neurological disorders, making these enzymes potential therapeutic targets. Understanding the precise mechanisms and substrates of geranylgeranyltransferases is an ongoing area of research in molecular biology and biochemistry.