Ras-related protein Ral-B
Function
Multifunctional GTPase involved in a variety of cellular processes including gene expression, cell migration, cell proliferation, oncogenic transformation and membrane trafficking (PubMed:10393179, PubMed:17875936, PubMed:18756269). Accomplishes its multiple functions by interacting with distinct downstream effectors. Acts as a GTP sensor for GTP-dependent exocytosis of dense core vesicles (By similarity). Required both to stabilize the assembly of the exocyst complex and to localize functional exocyst complexes to the leading edge of migrating cells (By similarity). Required for suppression of apoptosis (PubMed:17875936). In late stages of cytokinesis, upon completion of the bridge formation between dividing cells, mediates exocyst recruitment to the midbody to drive abscission (PubMed:18756269). Involved in ligand-dependent receptor mediated endocytosis of the EGF and insulin receptors (PubMed:10393179).
Post-translational modifications
Prenylation is essential for membrane localization. The geranylgeranylated form and the farnesylated mutant does not undergo alternative prenylation in response to geranylgeranyltransferase I inhibitors (GGTIs) and farnesyltransferase I inhibitors (FTIs).
The farnesylated form confers resistance to the proapoptotic and anti-anchorage-dependent growth effects of geranylgeranyltransferase I inhibitors, including GGTI-2417.
Sequence Similarities
Belongs to the small GTPase superfamily. Ras family.
Cellular localization
- Cell membrane
- Lipid-anchor
- Cytoplasmic side
- Midbody
- During late cytokinesis, enriched at the midbody.
Alternative names
Ras-related protein Ral-B, RALB