Brain-selective kinase (BRSK1) is a serine/threonine-protein kinase that plays a key role in polarization of neurons and centrosome duplication. BRSK1 phosphorylates CDC25B, CDC25C, MAPT/TAU, RIMS1, TUBG1, TUBG2 and WEE1. Following phosphorylation and activation by STK11/LKB1, BRSK1 acts as a key regulator of polarization of cortical neurons, probably by mediating phosphorylation of microtubule-associated proteins such as MAPT/TAU at 'Ser-579'. It also regulates neuron polarization by mediating phosphorylation of WEE1 at 'Ser-642' in post-mitotic neurons, leading to down-regulate WEE1 activity in polarized neurons. In neurons, BRSK1 localizes to synaptic vesicles and plays a role in neurotransmitter release, possibly by phosphorylating RIMS1. BRSK1 also acts as a positive regulator of centrosome duplication by mediating phosphorylation of gamma-tubulin (TUBG1 and TUBG2) at 'Ser-131', leading to translocation of gamma-tubulin and its associated proteins to the centrosome. BRSK1 is involved in the UV-induced DNA damage checkpoint response, probably by inhibiting CDK1 activity through phosphorylation and activation of WEE1, and inhibition of CDC25B and CDC25C [taken from the Universal Protein Resource (UniProt) www.uniprot.org/uniprot/Q13362].