HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by MacNicol, M. C. Articles by MacNicol, A. M. Search for Related Content PubMed PubMed Citation Articles by MacNicol, M. C. Articles by MacNicol, A. M. Social Bookmarking                      What's this?

J Biol Chem, Vol. 275, Issue 6, 3803-3809, February 11, 2000

Disruption of the 14-3-3 Binding Site within the B-Raf Kinase Domain Uncouples Catalytic Activity from PC12 Cell Differentiation^*

Melanie C. MacNicol, Anthony J. Muslin^§, and Angus M. MacNicol^¶

From the  Department of Medicine and ^¶ The Ben May Institute for Cancer Research, The University of Chicago, Chicago, Illinois 60637 and the ^§ Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110

A number of Raf-associated proteins have recently been identified, including members of the 14-3-3 family of phosphoserine-binding proteins. Although both positive and negative regulatory functions have been ascribed for 14-3-3 interactions with Raf-1, the mechanisms by which 14-3-3 binding modulates Raf activity have not been fully established. We report that mutational disruption of 14-3-3 binding to the B-Raf catalytic domain inhibits B-Raf biological activity. Expression of the isolated B-Raf catalytic domain (B-Rafcat) induces PC12 cell differentiation in the absence of nerve growth factor. By contrast, the B-Rafcat 14-3-3 binding mutant, B-Rafcat S728A, was severely compromised for the induction of PC12 cell differentiation. Interestingly, the B-Rafcat 14-3-3 binding mutant retained significant in vitro catalytic activity. In Xenopus oocytes, the analogous full-length B-Raf 14-3-3 binding mutant blocked progesterone-stimulated maturation and the activation of endogenous mitogen-activated protein kinase kinase and mitogen-activated protein kinase. Similarly, the full-length B-Raf 14-3-3 binding mutant inhibited nerve growth factor-stimulated PC12 cell differentiation. We conclude that 14-3-3 interaction with the catalytic domain is not required for kinase activity per se but is essential to couple B-Raf catalytic activity to downstream effector activation.

---

^* This work was supported by National Institutes of Health Grants CA 70846 (to A. M. M.) and GM 54670 (to A. J. M.).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: Dept. of Medicine, The University of Chicago, 5841 S. Maryland Ave., Chicago, IL 60637. Tel.: 773-702-2676; Fax: 773-702-2681; E-mail: amacnico@medicine. bsd.uchicago.edu.

---

Copyright © 2000 by The American Society for Biochemistry and Molecular Biology, Inc.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				B. Wang, Y. Yang, and P. A. Friedman Na/H Exchange Regulatory Factor 1, a Novel AKT-associating Protein, Regulates Extracellular Signal-regulated Kinase Signaling through a B-Raf-Mediated Pathway Mol. Biol. Cell, April 1, 2008; 19(4): 1637 - 1645. [Abstract] [Full Text] [PDF]

				D. Bridges and G. B. G. Moorhead 14-3-3 Proteins: A Number of Functions for a Numbered Protein Sci. Signal., August 9, 2005; 2005(296): re10 - re10. [Abstract] [Full Text] [PDF]

				D. Bridges and G. B. G. Moorhead 14-3-3 Proteins: A Number of Functions for a Numbered Protein Sci. Signal., July 20, 2004; 2004(242): re10 - re10. [Abstract] [Full Text] [PDF]

				C. E. Rocheleau, R. M. Howard, A. P. Goldman, M. L. Volk, L. J. Girard, and M. V. Sundaram A lin-45 raf Enhancer Screen Identifies eor-1, eor-2 and Unusual Alleles of Ras Pathway Genes in Caenorhabditis elegans Genetics, May 1, 2002; 161(1): 121 - 131. [Abstract] [Full Text] [PDF]

				Y. Wang, R. T. Waldron, A. Dhaka, A. Patel, M. M. Riley, E. Rozengurt, and J. Colicelli The RAS Effector RIN1 Directly Competes with RAF and Is Regulated by 14-3-3 Proteins Mol. Cell. Biol., February 1, 2002; 22(3): 916 - 926. [Abstract] [Full Text] [PDF]

				R. D. York, D. C. Molliver, S. S. Grewal, P. E. Stenberg, E. W. McCleskey, and P. J. S. Stork Role of Phosphoinositide 3-Kinase and Endocytosis in Nerve Growth Factor-Induced Extracellular Signal-Regulated Kinase Activation via Ras and Rap1 Mol. Cell. Biol., November 1, 2000; 20(21): 8069 - 8083. [Abstract] [Full Text]

				W. Qiu, S. Zhuang, F. C. von Lintig, G. R. Boss, and R. B. Pilz Cell Type-specific Regulation of B-Raf Kinase by cAMP and 14-3-3 Proteins J. Biol. Chem., October 6, 2000; 275(41): 31921 - 31929. [Abstract] [Full Text] [PDF]