The Polycystic Kidney Disease 1 Gene Product Mediates Protein Kinase C α-dependent and c-Jun N-terminal Kinase-dependent Activation of the Transcription Factor AP-1

doi:10.1074/jbc.273.11.6013

The Polycystic Kidney Disease 1 Gene Product Mediates Protein Kinase C α-dependent and c-Jun N-terminal Kinase-dependent Activation of the Transcription Factor AP-1*

From the ^‡Renal Division and the ^‡Cardiology Division, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215 and the ^¶Laboratory of Molecular and Developmental Neuroscience, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114

Abstract

Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary disorder that accounts for 8–10% of end stage renal disease. PKD1, one of two recently isolated ADPKD gene products, has been implicated in cell-cell and cell-matrix interactions. However, the signaling pathway of PKD1 remains undefined. We found that the C-terminal 226 amino acids of PKD1 transactivate an AP-1 promoter construct in human embryonic kidney cells (293T). PKD1-induced transcription is specific for AP-1; promoter constructs containing cAMP response element-binding protein, c-Fos, c-Myc, or NFκB-binding sites are unaffected by PKD1. In vitro kinase assays revealed that PKD1 triggers the activation of c-Jun N-terminal kinase (JNK), but not of mitogen-activated protein kinases p38 or p44. Dominant-negative Rac-1 and Cdc42 mutations abrogated PKD1-mediated JNK and AP-1 activation, suggesting a critical role for small GTP-binding proteins in PKD1-mediated signaling. Several protein kinase C (PKC) inhibitors decreased PKD1-mediated AP-1 activation. Conversely, expression of the C-terminal domain of PKD1 increased PKC activity in 293T cells. A dominant-negative PKC α, but not a dominant-negative PKC β or δ, abrogated PKD1-mediated AP-1 activation. These findings indicate that small GTP-binding proteins and PKC α mediate PKD1-induced JNK/AP-1 activation, together comprising a signaling cascade that may regulate renal tubulogenesis.

Footnotes

↵* This work was supported by a grant from the Polycystic Kidney Research Foundation (to G. W.).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.
↵§ Supported by a Research Fellowship of the Belgian American Educational Foundation, Belgium.
↵‖ Supported by Public Health Service Grant MH-01147.
↵** Supported by the Deutsche Forschungsgemeinschaft, Germany.
↵§§ To whom correspondence should be addressed: Renal Div., Dept. of Medicine, Beth Israel Deaconess Medical Center, 330 Brookline Ave., Boston, MA 02215. Fax: 617-667-1610; E-mail: gwalz{at}bidmc.harvard.edu.
↵1 The abbreviations used are: ADPKD, autosomal dominant polycystic kidney disease; JNK, c-Jun N-terminal kinase; HA, hemagglutinin; MAP, mitogen-activated protein; PKC, protein kinase C; TRE, 12-O-tetradecanoylphorbol-13-acetate-responsive element; AP-1, activation protein 1; NFκB, nuclear factor κB; PAGE, polyacrylamide gel electrophoresis; BAPTA, 1,2-bis-(o-aminophenoxy)-ethane-N,N,N′,N′-tetra-acetic acid; HNF, hepatic nuclear factor.
- Received October 20, 1997.
- Revision received December 16, 1997.
The American Society for Biochemistry and Molecular Biology, Inc.