The MAPK Kinase Kinase TAK1 Plays a Central Role in Coupling the Interleukin-1 Receptor to Both Transcriptional and RNA-targeted Mechanisms of Gene Regulation

doi:10.1074/jbc.M004376200

The MAPK Kinase Kinase TAK1 Plays a Central Role in Coupling the Interleukin-1 Receptor to Both Transcriptional and RNA-targeted Mechanisms of Gene Regulation*

From the ^‡Institute of Pharmacology, Medical School Hannover, Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany and the ^§Department of Molecular Biology, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan

Abstract

Mechanisms of fulminant gene induction during an inflammatory response were investigated using expression of the chemoattractant cytokine interleukin-8 (IL-8) as a model. Recently we found that coordinate activation of NF-κB and c-Jun N-terminal protein kinase (JNK) is required for strong IL-8 transcription, whereas the p38 MAP kinase (MAPK) pathway stabilizes the IL-8 mRNA. It is unclear how these pathways are coupled to the receptor for IL-1, an important physiological inducer of IL-8. Expression of the MAP kinase kinase kinase (MAPKKK) TAK1 together with its coactivator TAB1 in HeLa cells activated all three pathways and was sufficient to induce IL-8 formation, NF-κB + JNK2-mediated transcription from a minimal IL-8 promoter, and p38 MAPK-mediated stabilization of a reporter mRNA containing IL-8-derived regulatory mRNA sequences. Expression of a kinase-inactive mutant of TAK1 largely blocked IL-1-induced transcription and mRNA stabilization, as well as formation of endogenous IL-8. Truncated TAB1, lacking the TAK1 binding domain, or a TAK1-derived peptide containing a TAK1 autoinhibitory domain were also efficient in inhibition. These data indicate that the previously described three-pathway model of IL-8 induction is operative in response to a physiological stimulus, IL-1, and that the MAPKKK TAK1 couples the IL-1 receptor to both transcriptional and RNA-targeted mechanisms mediated by the three pathways.

Footnotes

↵* This work was supported by grants (Kr1143/2–3, SFB 244/B15, SFB 244/B18, Ho1116/2–1, III GK-GRK 99/2–98 (P4)) from the Deutsche Forschungsgemeinschaft (to H. H. and M. K.).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.: 49-511-532-2800; Fax: 49-511-532-4081; E-mail: Kracht.Michael@MH-Hannover.de.
Published, JBC Papers in Press, October 24, 2000, DOI 10.1074/jbc.M004376200
Abbreviations:

IL-1

interleukin-1

EMSA

electrophoretic mobility shift assay

HA

hemagglutinin

IP

immunoprecipitation

JNK

c-Jun N-terminal kinase

MAPK

mitogen-activated protein kinase

MAPKK

MAPK kinase

MAPKKK

MAPKK kinase

RLU

relative light units

TNF

tumor necrosis factor

TAB

TAK binding protein

GST

glutathione S-transferase

ELISA

enzyme-linked immunosorbent assay

PMSF

phenylmethylsulfonyl fluoride

DTT

dithiothreitol

PAGE

polyacrylamide gel electrophoresis

GFP

green fluorescent protein
- Received May 22, 2000.
- Revision received October 23, 2000.
The American Society for Biochemistry and Molecular Biology, Inc.