2005年4月
Phosphorylation of Ser-446 determines stability of MKP-7
JOURNAL OF BIOLOGICAL CHEMISTRY
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- 巻
- 280
- 号
- 15
- 開始ページ
- 14716
- 終了ページ
- 14722
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1074/jbc.M500200200
- 出版者・発行元
- AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
MAPK cascades can be negatively regulated by members of the MAPK phosphatase (MKP) family. However, how MKP activity is regulated is not well characterized. MKP-7, a JNK-specific phosphatase, possesses a unique COOH-terminal stretch (CTS) in addition to domains conserved among MKP family members. The CTS contains several motifs such as a nuclear localization signal, a nuclear export signal, PEST sequences, and a serine residue (Ser-446) that can be phosphorylated by activated ERK, suggesting an important regulatory role(s). S-35-pulse labeling experiments indicate that the half-life of MKP-7 is 1.5 h, a period significantly elongated by deleting the CTS. We also show that overexpressed MKP-7 is polyubiquitinated when co-expressed with ubiquitin and that proteasome inhibitors markedly inhibit MKP-7 degradation. We also determined that MKP-7 phosphorylated at Ser-446 has a longer half-life than unphosphorylated form of the wild type protein, as does a phospho-mimic mutant of MKP-7. These results indicate that activation of the ERK pathway strongly blocks JNK activation through stabilization of MKP-7 mediated by phosphorylation.
- リンク情報
- ID情報
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- DOI : 10.1074/jbc.M500200200
- ISSN : 0021-9258
- PubMed ID : 15689616
- Web of Science ID : WOS:000228236800048