Title

Identification of Poly (ADP-ribose) Polymerase-1 (PARP-1) as a Novel Kruppel-like Factor 8-interacting and -regulating Protein

Authors

Authors

H. Lu; X. H. Wang; T. S. Li; A. M. Urvalek; L. Yu; J. L. Li; J. H. Zhu; Q. S. Lin; X. Peng;J. H. Zhao

Comments

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Abbreviated Journal Title

J. Biol. Chem.

Keywords

FOCAL ADHESION KINASE; CELL-CYCLE PROGRESSION; NF-KAPPA-B; POLY(ADP-RIBOSE) POLYMERASE-1; KLF8 TRANSCRIPTION; NUCLEAR EXPORT; IN-VIVO; CANCER; TARGET; CARCINOGENESIS; Biochemistry & Molecular Biology

Abstract

Kruppel-like factor 8 (KLF8) regulates critical gene transcription and cellular events associated with cancer. However, KLF8-interacting proteins remain largely unidentified. Using co-immunoprecipitation (co-IP), mass spectrometry, and GST pulldown assays, we identified poly(ADP-ribose) polymerase-1(PARP-1) as a novel KLF8-interacting protein. Co-IP and Western blotting indicated that KLF8 is also a PARP-1 substrate. Mutation of the cysteines in the zinc finger domain of KLF8 abolished PARP-1 interaction. Surprisingly, immunofluorescent staining revealed a cytoplasmic mislocalization of KLF8 in PARP-1(-/-) cells or when the interaction was disrupted. This mislocalization was prevented by either PARP-1 re-expression or inhibition of CRM1-dependent nuclearexport. Interestingly, co-IP indicated competition between PARP-1 and CRM1 for KLF8 binding. Cycloheximide chase assay showed a decrease in the half-life of KLF8 protein when PARP-1 expression was suppressed or KLF8-PARP-1 interaction was disrupted. Ubiquitination assays implicated KLF8 as a target of ubiquitination that was significantly higher in PARP-1(-/-) cells. Promoter reporter assays and chromatin immunoprecipitation assays showed that KLF8 activation on the cyclin D1 promoter was markedly reduced when PARP-1 was deleted or inhibited or when KLF8-PARP-1 interaction was disrupted. Overall, this work has identified PARP-1 as a novel KLF8-binding and-regulating protein and provided new insights into the mechanisms underlying the regulation of KLF8 nuclear localization, stability, and functions.

Journal Title

Journal of Biological Chemistry

Volume

286

Issue/Number

23

Publication Date

1-1-2011

Document Type

Article

Language

English

First Page

20335

Last Page

20344

WOS Identifier

WOS:000291267600021

ISSN

0021-9258

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