Open Close
Reference
Citation
Hu, H., Marton, T.F., Goodman, C.S. (2001). Plexin b mediates axon guidance in Drosophila by simultaneously inhibiting active rac and enhancing rhoa signaling.  Neuron 32(1): 39--51.
FlyBase ID
FBrf0139777
Publication Type
Research paper
Abstract

Plexins are neuronal receptors for the repulsive axon guidance molecule Semaphorins. Previous studies showed that Plexin B (PlexB) binds directly to the active, GTP-bound form of the Rac GTPase. Here, we define a seven amino acid sequence in PlexB required for Rac(GTP) binding. The interaction of PlexB with Rac(GTP) is necessary for Plexin-mediated axon guidance in vivo. A different region of PlexB binds to RhoA. Dosage-sensitive genetic interactions suggest that PlexB suppresses Rac activity and enhances RhoA activity. Biochemical evidence indicates that PlexB sequesters Rac(GTP) from its downstream effector PAK. These results suggest a model whereby PlexB mediates repulsion by coordinately regulating two small GTPases in opposite directions: PlexB binds to Rac(GTP) and downregulates its output by blocking its access to PAK and, at the same time, binds to and increases the output of RhoA.

PubMed ID
PubMed Central ID
Related Publication(s)
Review

Plexin signaling via off-track and rho family GTPases.
Whitford and Ghosh, 2001, Neuron 32(1): 1--3 [FBrf0141776]

Associated Information
Comments
Associated Files
Other Information
Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Neuron
    Title
    Neuron
    Publication Year
    1988-
    ISBN/ISSN
    0896-6273
    Data From Reference
    Aberrations (2)
    Alleles (10)
    Genes (10)
    Physical Interactions (4)
    Insertions (2)
    Experimental Tools (2)
    Transgenic Constructs (6)