Green Tea Research Today is a free monthly online journal that collates and summarizes the latest research about Green Tea, including details on benefits, antioxidants, weight loss, diet, side effects.

Phosphorylation of Recombinant Tristetraprolin In vitro.

Cao H, Lin R

Diet, Genomics and Immunology Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, US Department of Agriculture, Building 307C, BARC-East, 10300 Baltimore Avenue, Beltsville, MD, 20705, USA.

Tristetraprolin/zinc finger protein 36 (TTP/ZFP36) binds and destabilizes some proinflammatory cytokine mRNAs. TTP-deficient mice develop a profound inflammatory syndrome due to excessive production of proinflammatory cytokines. TTP gene expression is induced by various factors including insulin, cinnamon, and green tea extracts. Previous studies have shown that TTP is highly phosphorylated in vivo and multiple phosphorylation sites are identified in human TTP. This study evaluated the potential protein kinases that could phosphorylate recombinant TTP in vitro. Motif scanning suggested that TTP was a potential substrate for various kinases. SDS-PAGE showed that in vitro phosphorylation of TTP with p42 and p38 MAP kinases resulted in visible electrophoretic mobility shift of TTP to higher molecular masses. Autoradiography showed that TTP was phosphorylated in vitro by GSK3b, PKA, PKB, PKC, but not Cdc2, in addition to p42, p38, and JNK. These results demonstrate that TTP is a substrate for a number of protein kinases in vitro.

Published 11 December 2007 in Protein J.
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