p160 RhoA-binding Kinase ROKα Induces Neurite Retraction*
- From the Department of Physiological Chemistry and the‡Department of Molecular Neurobiology, Faculty of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606, Japan
Abstract
We previously reported that the activation of prostaglandin E receptor EP3 subtype caused neurite retraction via small GTPase Rho in the EP3B receptor-expressing PC12 cells (Katoh, H., Negishi, M., and Ichikawa, A. (1996) J. Biol. Chem.271, 29780–29784). However, a potential downstream effector of Rho that induces neurite retraction was not identified. Here we examined the morphological effect of p160 RhoA-binding kinase ROKα, a target for RhoA recently identified, on the nerve growth factor-differentiated PC12 cells. Microinjection of the catalytic domain of ROKα rapidly induced neurite retraction similar to that induced by microinjection of a constitutively active Rho, RhoV14, whereas microinjection of the kinase-deficient catalytic domain of ROKα did not induce neurite retraction. This morphological change was observed even though C3 exoenzyme, which was known to inactivate Rho, had been preinjected. On the other hand, microinjection of the Rho-binding domain or the pleckstrin homology domain of ROKα inhibited the EP3 receptor-induced neurite retraction. These results demonstrate that ROKα induces neurite retraction acting downstream of Rho in neuronal cells.
Footnotes
-
↵* This work was supported in part by Grants-in-aid for Scientific Research 09273105, 09259219, and 09307052 from the Ministry of Education, Science, and Culture of Japan.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
-
↵§ To whom correspondence should be addressed. Tel.: 81-75-753-4547; Fax: 81-75-753-4557; E-mail: mnegishi{at}pharm.kyoto-u.ac.jp.
-
↵1 The abbreviations used are: G-protein, GTP-binding protein; PCR, polymerase chain reaction; GST, glutathioneS-transferase; PH, pleckstrin homology; PHD, PH domain; NGF, nerve growth factor; CD, catalytic domain; RBD, Rho-binding domain.
-
- Received October 14, 1996.
- Revision received December 1, 1997.
- The American Society for Biochemistry and Molecular Biology, Inc.
