The interleukin‐1‐stimulated protein kinase that phosphorylates heat shock protein hsp27 is activated by MAP kinase

FEBS Letters

Bird, T.A.²  Delaney, P.²  Virca, G.D.¹  de Roos, P.¹  Dower, S.K.²  Sleath, P.¹  Schule, H.D.² 

[1] Department of Protein Chemistry, Immunex Corporation, 51 University Street, Seattle, WA 98101, USA;Department of Biochemistry Immunex Corporation, 51 University Street, Seattle, WA 98101, USA

关键词: Protein kinase;    Interleukin-1;    Signal transduction;    Protein phosphorylation;    EGF;    epidermal growth factor;    hsp27;    27 kilodalton heat shock protein;    IL-1;    interleukin-1α;    MAP kinase;    mitogen-activated protein kinase;    MOPS;    3-(N-morpholino)propanesulfonic acid;    PMA;    phorbol 12-myristate 13-acetate;    PP-2a;    protein phosphatase;    type-2a;    RSK;    ribosomal protein S6 kinase II;   

DOI  :  10.1016/0014-5793(94)80111-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In KB cells, interleukin-1 (IL-1), epidermal growth factor and phorbol ester transiently activated both MAP kinase and a serine kinase which phosphorylated the heat shock protein hsp27. Extracts made from IL-1-stimulated KB cells phosphorylated recombinant hsp27, in vitro, on serine residues 78 and 82 which are contained within Arg-X-X-Ser motifs similar to those phosphorylated by the ribosomal protein S6 kinases. Upon size exclusion chromatography, however, hsp27 kinase eluted as a single peak of activity at 50–60 kDa, clearly separated from ribosomal protein S6 kinases. Treatment of partially purified hsp27 kinase with protein phosphatase-2a reduced its activity by 80%. De-phosphorylated hsp27 kinase could be approximately 50% reactivated by a factor present in IL-1-treated cell extracts in the presence of ATP. This factor co-eluted with MAP kinase after partial purification by DEAE-cellulose, phenyl Sepharose, and size exclusion chromatography. Purified sea star p44^mpk and recombinant ERK2 MAP kinases were also capable of re-activating hsp27 kinase to a similar extent. These data suggest that hsp27 kinase is downstream from, and probably a direct target of MAP kinase.

【 授权许可】

Unknown