Lale Ozcan, Catherine C L Wong, Gang Li, Tao Xu, Utpal Pajvani, Sung Kyu Robin Park, Anetta Wronska, Bi-Xing Chen, Andrew R Marks, Akiyoshi Fukamizu, Johannes Backs, Harold A Singer, John R Yates, Domenico Accili, Ira Tabas
Hepatic glucose production (HGP) is crucial for glucose homeostasis, but the underlying mechanisms have not been fully elucidated. Here, we show that a calcium-sensing enzyme, CaMKII, is activated in a calcium- and IP3R-dependent manner by cAMP and glucagon in primary hepatocytes and by glucagon and fasting in vivo. Genetic deficiency or inhibition of CaMKII blocks nuclear translocation of FoxO1 by affecting its phosphorylation, impairs fasting- and glucagon/cAMP-induced glycogenolysis and gluconeogenesis, and lowers blood glucose levels, while constitutively active CaMKII has the opposite effects...
May 2, 2012: Cell Metabolism