4‐Isoavenaciolide covalently binds and inhibits VHR, a dual‐specificity phosphatase

FEBS Letters

Osada, Hiroyuki²  Nakayama, Hiroshi³  Takio, Koji³  Ubukata, Makoto¹  Usui, Takeo²  Ueda, Kazunori²  Ueki, Masashi² 

[1] Laboratory of Biofunctional Chemistry, Biotechnology Research Center, Toyama Prefectural University, Kosugi-machi, Toyama 939-0398, Japan;Antibiotics Laboratory, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan;Biomolecular Characterization Division, RIKEN, Hirosawa 2-1, Wako-shi, Saitama 351-0198, Japan

关键词: Dual-specificity phosphatase;    4-Isoavenaciolide;    Michael addition;    Liquid chromatography–tandem mass spectrometry;    IC50;    50% inhibitory concentration;    PTPase;    protein tyrosine phosphatase;    DSPase;    dual-specificity phosphatase;    VHR;    vaccinia H1 related;    pNPP;    p-nitrophenyl phosphate;    LC–MS/(MS);    liquid chromatography–(tandem) mass spectrometry;    PP1;    protein phosphatase 1;    PP2A;    protein phosphatase 2A;    ERK;    extracellular signal-regulated kinase;    4-iA;    4-isoavenaciolide;   

DOI  :  10.1016/S0014-5793(02)03065-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A potent inhibitor of a dual-specificity protein phosphatase, VHR (vaccinia H1 related), was isolated during a screening of microbial metabolites. This inhibitor was identified as 4-isoavenaciolide (4-iA), and was determined to irreversibly inhibit VHR phosphatase activity with a 50% inhibitory concentration of 1.2 μM. Detailed tandem mass spectrometry analyses of proteolysed fragments revealed that two molecules of 4-iA bound a molecule of VHR at the two different fragments: one containing the catalytic domain and the other containing the α6 helix positioned surface domain. As 4-iA possesses a reactive exo-methylene moiety, it is possible that 4-iA inhibits VHR through the direct binding to the cysteine residue in the catalytic site (Cys124). Furthermore, 4-iA inhibited dual-specificity protein phosphatases and tyrosine phosphatases, but did not inhibit serine/threonine phosphatases. These results suggest that 4-iA is a cysteine-targeting inhibitor of protein phosphatases with a common HCX₅RS/T motif in the catalytic site.

【 授权许可】

Unknown