background:
EPHEXIN is a 710 amino acid protein that localizes to both the membrane and the cytoplasm and contains one SH3 domain, one PH domain and one DH domain. Expressed at high levels in brain and present at lower levels in lung tissue, EPHEXIN interacts with EphA4 and functions as a guanine nucleotide exchange factor (GEF) that is capable of activating Rho A, Rac 1 and Cdc42 and is thought to play a role in axon guidance and growth cone collapse. EPHEXIN is subject to Src-dependent phosphorylation, an event that increases the GEF activity of EPHEXIN toward Rho A. Human EPHEXIN, which exists as multiple alternatively spliced isoforms, shares a high degree of sequence homology with its mouse counterpart, suggesting a conserved role between species.
Function:
Acts as a guanine nucleotide exchange factor (GEF) which differentially activates the GTPases RHOA, RAC1 and CDC42. Plays a role in axon guidance regulating ephrin-induced growth cone collapse. Upon activation by ephrin through EPHA4, the GEF activity switches toward RHOA resulting in its activation. Activated RHOA promotes cone retraction at the expense of RAC1-and CDC42-stimulated growth cone extension.
Subunit:
Interacts with CDK5R1 and EPHA4; activated by EPHA4 through the CDK5 kinase
Subcellular Location:
Cytoplasm. Membrane. Cell projection, growth cone. Associated with membranes. Localizes to axonal growth cones.
Tissue Specificity:
Highly expressed in brain specifically in caudate nucleus and to a lower extent in amygdala and hippocampus. Also detected in lung.
Post-translational modifications:
Src-dependent phosphorylation at Tyr-179 upon EPHA4 activation increases the guanine exchange factor activity toward RHOA.
Similarity:
Contains 1 DH (DBL-homology) domain.
Contains 1 PH domain.
Contains 1 SH3 domain.
Database links:
Entrez Gene: 25791 Human
Entrez Gene: 53972 Mouse
Entrez Gene: 246217 Rat
Entrez Gene: 424744 Chicken
Omim: 605991 Human
SwissProt: Q8N5V2 Human
SwissProt: Q8CHT1 Mouse
SwissProt: Q5BKC9 Rat
Unigene: 97316 Human
Unigene: 435439 Mouse
Unigene: 20670 Rat
Important Note:
This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications.
|
|
