Cloning of a novel kinase (SIK) of the SNF1/AMPK family from high salt diet-treated rat adrenal

PCR-coupled cDNA subtraction hybridization was adapted to identify the gene s ex:pressed in the adrenocortical tissues from high salt diet-treated rat. A novel cDNA clone, termed salt-inducible kinase (SIK), encoding a polypep tide (776 amino acids) with significant similarity to protein serine/threon ine kinases in the SNF1/AMPK family was isolated. An in vitro kinase assay demonstrated that SIK protein had autophosphorylation activity. Northern bl ot revealed that SIK mRNA levels were markedly augmented by ACTH treatment both in rat adrenal glands and in Y1 cells. SIK may play an important role in the regulation of adrenocortical functions in response to high plasma sa lt and ACTH stimulation, (C) 1999 Federation of European Biochemical Societ ies.