The salt-inducible kinase, SIK, is induced by depolarization in brain

Membrane depolarization of neurons is thought to lead to changes in gene ex pression that modulate neuronal plasticity, We used representational differ ence analysis to identify a group of cDNAs that are induced by membrane dep olarization or by forskolin, but not by neurotrophins or growth factors, in PC12 pheochromocytoma cells. One of these genes, SIK ((s) over bar alt-(i) over bar nducible (k) over bar inase), is a member of the sucrose-nonferme nting 1 protein kinase/AMP-activated protein kinase protein kinase family t hat was also recently identified from the adrenal gland of rats treated wit h high-salt diets. SIK mRNA is induced up to eightfold in specific regions of the hippocampus and cortex in rats, following systemic kainic acid admin istration and seizure induction.