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Inhibition of heat‐induced phosphorylation of stathmin by the bioflavonoid quercetin
Author(s) -
Nagasaka Yuji,
Fijimoto Masanori,
Arai Hirofumi,
Nakamura Kazuyuki
Publication year - 2002
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200202)23:4<670::aid-elps670>3.0.co;2-3
Subject(s) - stathmin , phosphorylation , staurosporine , quercetin , kinase , heat shock protein , chemistry , protein kinase a , microbiology and biotechnology , biochemistry , biology , gene , antioxidant
Effects of quercetin on heat‐induced phosphorylation of stathmin in JURKAT cells were examined. Two‐dimensional electrophoresis of stathmin showed that heat shock increases mono‐ and diphosphorylation of stathmin. Monophosphorylation induced by heat shock was inhibited by the presence of 0.1 m M quercetin, but not by the presence of 0.1 ν M staurosporine. Immunoblot analysis of phosphorylated stathmin showed that heat‐induced phosphorylation at Ser‐38 was inhibited by quercetin but not by staurosporine. Quercetin enhanced heat‐induced tyrosine phosphorylation of MAP kinase. These observations indicate that quercetin inhibits heat‐induced phosphorylation at Ser‐38 of stathmin but mitogen‐activated protein (MAP) kinase is not involved in its phosphorylation.