BRSK2

BRSK2, also named SAD-A, is the second brain-enriched AMPK-related kinase, activated by LKB1 phosphorylation and cooperating with BRSK1 in neuronal development. It is additionally expressed in pancreatic islets, where functional studies implicate it in insulin granule exocytosis and glucose-stimulated insulin secretion. Like BRSK1, BRSK2 phosphorylates tau and microtubule-associated proteins, influencing cytoskeletal dynamics, and the two kinases act redundantly in many contexts, with combined loss causing severe defects in axon specification and synapse formation. Its catalytic domain is highly similar to BRSK1, yet the distinct tissue distribution suggests specialized endocrine roles beyond the brain, distinguishing BRSK2 from its purely neuronal sibling.