A possible tyrosine phosphorylation of phytochrome

FEBS Letters

Wells, Todd A.¹  Sommer, Debbie¹ 

[1] Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA

关键词: Phosphorylation;    Signal transduction;    Phytochrome;    Avena;    BSA;    bovine serum albumin;    ECL;    enhanced chemiluminescence;    GAP;    GTPase-activating protein;    MAPK;    mitogen-activated protein kinase;    PBS;    phosphate-buffered saline;    PBST;    phosphate-buffered saline containing 0.05% Tween 20;    Pfr;    far-red absorbing form of phytochrome;    Phy;    phytochrome;    PI3-kinase;    phosphatidylinositol 3-kinase;    PLC;    phospholipase C;    PMSF;    phenylmethanesulfonyl fluoride;    Pr;    red-absorbing form of phytochrome;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(96)00876-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Red/far-red light signal transduction by the phytochrome family of photoreceptors regulates plant growth and development. We investigated the possibility that tyrosine kinases and/or phosphatases are involved in phytochrome-mediated signal transduction using crude extracts of oat seedlings that are grown in the dark. We found that a 124 kDa protein was tyrosine-phosphorylated as determined by Western blotting with a phosphotyrosine-specific monoclonal antibody. The 124 kDa protein was recognized by the anti-phosphotyrosine antibody in anti-phytochrome A immunoprecipitates. The level of anti-phosphotyrosine antibody binding to the 124 kDa protein(s) in phytochrome immunoprecipitates that had been treated with red light prior to immunoprecipitation decreased relative to dark controls. These results suggest that either phytochrome from dark-grown seedlings is tyrosine phosphorylated or that it co-immunoprecipitates with a phosphotyrosine-containing protein of the same molecular weight. The implications of these results in the regulation of (a) the putative Ser/Thr kinase activity of the photoreceptor and (b) the binding of signaling molecules, such as phospholipase C to phytochrome, are discussed.

【 授权许可】

Unknown