The Semaphorin 4D receptor Plexin-B1 is a GTPase activating protein for R-Ras.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 15297673.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Plexins are cell surface receptors for semaphorin molecules, and their interaction governs cell adhesion and migration in a variety of tissues. We report that the Semaphorin 4D (Sema4D) receptor Plexin-B1 directly stimulates the intrinsic guanosine triphosphatase (GTPase) activity of R-Ras, a member of the Ras superfamily of small GTP-binding proteins that has been implicated in promoting cell adhesion and neurite outgrowth. This activity required the interaction of Plexin-B1 with Rnd1, a small GTP-binding protein of the Rho family. Down-regulation of R-Ras activity by the Plexin-B1-Rnd1 complex was essential for the Sema4D-induced growth cone collapse in hippocampal neurons. Thus, Plexin-B1 mediates Sema4D-induced repulsive axon guidance signaling by acting as a GTPase activating protein for R-Ras.
Medical subject headings
- Antigens, CD
- GTP Phosphohydrolases
- GTPase-Activating Proteins
- Membrane Glycoproteins
- Neurons
- Receptors, Cell Surface
- Semaphorins
- ras Proteins