Inhibition of heat-induced phosphorylation of stathmin by the bioflavonoid quercetin.
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 mM quercetin, but not by the presence of 0.1 microM 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.
Nagasaka
Yuji
Y
Department of Human Nutrition, Yamaguchi Prefectural University, Yamaguchi, Japan.
Fijimoto
Masanori
M
Arai
Hirofumi
H
Nakamura
Kazuyuki
K
D005419:Flavonoids / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D015151:Immunoblotting; D019169:Jurkat Cells; D008868:Microtubule Proteins; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011794:Quercetin / Q000494:pharmacology*; D012694:Serine / Q000378:metabolism; D050777:Stathmin; D019311:Staurosporine / Q000494:pharmacology
D005419:Flavonoids; D008868:Microtubule Proteins; D010750:Phosphoproteins; C493995:STMN1 protein, human; D050777:Stathmin; D012694:Serine; D011794:Quercetin; D020928:Mitogen-Activated Protein Kinases; D019311:Staurosporine