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

J. Biol. Chem., Vol. 283, Issue 28, 19245-19254, July 11, 2008

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 283/28/19245    most recent M800943200v1 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 Google Scholar Articles by Prickett, T. D. Articles by Brautigan, D. L. PubMed PubMed Citation Articles by Prickett, T. D. Articles by Brautigan, D. L. Social Bookmarking                      What's this?

TAB4 Stimulates TAK1-TAB1 Phosphorylation and Binds Polyubiquitin to Direct Signaling to NF-B^*

Todd D. Prickett, Jun Ninomiya-Tsuji, Peter Broglie, Tara L. Muratore-Schroeder^¶, Jeffrey Shabanowitz^¶, Donald F. Hunt^¶, and David L. Brautigan¹

From the Center for Cell Signaling and Department of Microbiology, University of Virginia School of Medicine, Charlottesville, Virginia 22908, Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, North Carolina 27695, and ^¶Department of Chemistry, University of Virginia, Charlottesville, Virginia 22908

Responses to transforming growth factor β and multiple cytokines involve activation of transforming growth factor β-activated kinase-1 (TAK1) kinase, which activates kinases IB kinase (IKK) and MKK3/6, leading to the parallel activation of NF-B and p38 MAPK. Activation of TAK1 by autophosphorylation is known to involve three different TAK1-binding proteins (TABs). Here we report a protein phosphatase subunit known as type 2A phosphatase-interacting protein (TIP) that also acts as a TAB because it co-precipitates with and directly binds to TAK1, enhances TAK1 autophosphorylation at unique sites, and promotes TAK1 phosphorylation of IKKβ and signaling to NF-B. Mass spectrometry demonstrated that co-expression of TAB4 protein significantly increased phosphorylation of four sites in TAK1, in a linker region between the kinase and TAB2/3 binding domains, and two sites in TAB1. Recombinant GST-TAB4 bound in an overlay assay directly to inactive TAK1 and activated TAK1 but not TAK1 phosphorylated in the linker sites, suggesting a bind and release mechanism. In kinase assays using TAK1 immune complexes, added GST-TAB4 selectively stimulated IKK phosphorylation. TAB4 co-precipitated polyubiquitinated proteins dependent on a Phe-Pro motif that was required to enhance phosphorylation of TAK1. TAB4 mutated at Phe-Pro dominantly interfered with IL-1β activation of NF-B involving IKK-dependent but not p38 MAPK-dependent signaling. The results show that TAB4 binds TAK1 and polyubiquitin chains to promote specific sites of phosphorylation in TAK1-TAB1, which activates IKK signaling to NF-B.

Received for publication, February 5, 2008 , and in revised form, April 30, 2008.

^* This work was supported, in whole or in part, by National Institutes of Health Grants CA77584 (to D. L. B.), GM068812 (to J. N.-T.), and GM-37537 (to D. F. H.) from the United States Public Health Service. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains a supplemental figure.

¹ To whom correspondence should be addressed: University of Virginia, Box 800577, West Complex, Rm. 7225, 1400 Jefferson Park Ave., Charlottesville, VA 22908. Tel.: 434-924-5892; Fax: 434-243-2829; E-mail: db8g{at}virginia.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?