Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Eph-dependent tyrosine phosphorylation of ephexin1 modulates growth cone collapse.

Neuron | Apr 21, 2005

Ephs regulate growth cone repulsion, a process controlled by the actin cytoskeleton. The guanine nucleotide exchange factor (GEF) ephexin1 interacts with EphA4 and has been suggested to mediate the effect of EphA on the activity of Rho GTPases, key regulators of the cytoskeleton and axon guidance. Using cultured ephexin1-/- mouse neurons and RNA interference in the chick, we report that ephexin1 is required for normal axon outgrowth and ephrin-dependent axon repulsion. Ephexin1 becomes tyrosine phosphorylated in response to EphA signaling in neurons, and this phosphorylation event is required for growth cone collapse. Tyrosine phosphorylation of ephexin1 enhances ephexin1's GEF activity toward RhoA while not altering its activity toward Rac1 or Cdc42, thus changing the balance of GTPase activities. These findings reveal that ephexin1 plays a role in axon guidance and is regulated by a switch mechanism that is specifically tailored to control Eph-mediated growth cone collapse.

Pubmed ID: 15848799 RIS Download

Mesh terms: Actins | Amino Acid Sequence | Animals | Blotting, Western | Cells, Cultured | Chick Embryo | Cytoskeleton | Growth Cones | Guanine Nucleotide Exchange Factors | Immunohistochemistry | Mice | Phosphorylation | Receptor, EphA1 | Sequence Homology, Amino Acid | Tyrosine | rho GTP-Binding Proteins

Research resources used in this publication

None found

Research tools detected in this publication

None found

Data used in this publication

None found

Associated grants

  • Agency: NINDS NIH HHS, Id: R01 NS35884
  • Agency: NICHD NIH HHS, Id: K08 HD01384
  • Agency: NINDS NIH HHS, Id: NS45500
  • Agency: NINDS NIH HHS, Id: R01 NS045500
  • Agency: NICHD NIH HHS, Id: HD18655
  • Agency: NIMH NIH HHS, Id: R01 MH59894

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.

We have not found any resources mentioned in this publication.