STK39 Recombinant Rabbit mAb (S-3630-15)

STK39 (Serine/Threonine Kinase 39), also known as SIK3 or salt-inducible kinase 3, is a multifunctional enzyme belonging to the AMP-activated protein kinase (AMPK) family within the broader serine/threonine kinase group, playing pivotal roles in regulating cellular metabolism, ion transport, and circadian rhythms. Primarily activated by upstream kinases such as LKB1, STK39 functions as a critical mediator in response to hormonal signals like aldosterone and insulin, where it phosphorylates specific substrates including the sodium-potassium-chloride cotransporter NKCC1 and various transcriptional co-repressors (such as HDAC4 and CRTC2) to modulate electrolyte balance, glucose homeostasis, and lipid metabolism. Beyond its metabolic duties, STK39 is integral to the molecular clock mechanism by influencing the periodicity of circadian gene expression through the regulation of CREB signaling pathways, and emerging research highlights its involvement in pathological conditions, including its potential tumor-suppressive or oncogenic roles depending on tissue context, as well as its contribution to neurodevelopmental disorders and pain sensitivity via neuronal signaling modulation.