- Mon1-Ccz1 complex
A protein complex that functions as a guanine nucleotide exchange factor (GEF) and converts Rab-GDP to Rab-GTP. In S. cerevisiae, this complex consists of at least Mon1 and Ccz1, and serves as a GEF for the Rab Ypt7p.
- Rab-protein geranylgeranyltransferase complex
An protein-containing complex which catalyzes of the transfer of a geranyl-geranyl group from geranylgeranyl pyrophosphate to a Rab protein. In mammals it is composed of an alpha and a beta subunit, and associates with an accessory protein Rep (Rab escort protein).
- Rab geranylgeranyltransferase activity
Catalysis of the reaction: 2 geranylgeranyl diphosphate + protein-cysteine = 2 S-geranylgeranyl-protein + 2 diphosphate. This reaction is the formation of two thioether linkages between the C-1 atom of the geranylgeranyl groups and two cysteine residues within the terminal sequence motifs XXCC, XCXC or CCXX. Known substrates include Ras-related GTPases of a single family and the Rab family.
- Rab protein signal transduction
The series of molecular signals within the cell that are mediated by a member of the Rab family of proteins switching to a GTP-bound active state.