SIKs are serine/threonine kinasse that are part of a complex network that regulates Na,K-ATPase to maintain sodium homeostasis and blood pressure []. Vertebrates contain three forms of SIKs (SIK1-3) from three distinct genes, which display tissue-specific effects. SIK1, also called SNF1LK, controls steroidogenic enzyme production in adrenocortical cells []. In the brain, both SIK1 and SIK2 regulate energy metabolism []. SIK2, also called QIK or SNF1LK2, is involved in the regulation of gluconeogenesis in the liver and lipogenesis in adipose tissues, where it phosphorylates the insulin receptor substrate-1 []. In the liver, SIK3 (also called QSK) regulates cholesterol and bile acid metabolism []. In addition, SIK2 plays an important role in the initiation of mitosis and regulates the localization of C-Nap1, a centrosome linker protein [].
