Rab protein geranylgeranyltransferase component A (IPR001738)

Short name: Rab_escort

Overlapping homologous superfamilies

Family relationships


Rab proteins constitute a family of small GTPases that serve a regulatory role in vesicular membrane traffic [PMID: 7957092, PMID: 8513495]; C-terminal geranylgeranylation is crucial for their membrane association and function. This post-translational modification is catalysed by Rab geranylgeranyl transferase (Rab-GGTase), a multi-subunit enzyme that contains a catalytic heterodimer and an accessory component, termed Rab escort protein (REP)-1 [PMID: 7957092, PMID: 8513495]. REP-1 presents newly-synthesised Rab proteins to the catalytic component, and forms a stable complex with the prenylated proteins following the transfer reaction.

cDNA cloning of component A of rat Rab geranylgeranyl transferase (REP) confirms its resemblance to Rab3A guanine nucleotide dissociation inhibitor (GDI) and its identity with the human choroideremia gene product [PMID: 8513495]. A genetic defect in REP underlies human choroideremia. Choroideraemia (or tapetochoroidal dystrophy) is a common form of X-linked blindness characterised by progressive dystrophy of the choroid, retinal pigment epithelium and retina [PMID: 2215697, PMID: 7981670, PMID: 1549574].

GO terms

Biological Process

GO:0006886 intracellular protein transport
GO:0018344 protein geranylgeranylation

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005968 Rab-protein geranylgeranyltransferase complex

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.