Rab geranylgeranyltransferase subunit alpha (RABGGTA)

Rab geranylgeranyltransferase subunit alpha (RABGGTA) is the alpha subunit of the heterodimeric Rab geranylgeranyltransferase enzyme (also called protein geranylgeranyltransferase type II). It catalyzes the transfer of geranylgeranyl moieties from geranylgeranyl diphosphate to the C-terminal cysteine residues of Rab GTPase proteins—a post-translational modification necessary for their membrane association and role in vesicular trafficking. Unlike other prenyltransferases, Rab GGTase relies on the Rab escort protein (REP) for substrate recognition and specificity. RABGGTA is essential for correct Rab protein localization and function across diverse cell types, and loss-of-function mutations can cause defects in intracellular trafficking, especially notable in blood platelets. In vitro, it can be inhibited by drugs such as nitrogen-containing bisphosphonates, though therapeutic applications are limited by essential housekeeping functions of the enzyme[1][5][6][2][9].

Other names

Geranylgeranyl transferase type-2 subunit alphaRab GG transferase alphaRab GGTase alphaPTAR3protein prenyltransferase alpha subunit repeat containing 3Rab geranyl-geranyltransferase subunit alpha

Inhibition of Rab GGTase activity, leading to impaired Rab protein prenylation and membrane localization[1][2]