Serine/threonine kinase which is able to phosphorylate TAU on serine, threonine and tyrosine residues. Induces aggregation of TAU (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Divalent metal cations. Mg(2+) or, to a lesser extent, Mn(2+), but not Ca(2+) or Zn(2+). Expressed in the brain. Strong expression in the cortical layers, the CA1 layers of the hippocampus and the granular layer of the cerebellum. Also expressed in the large cortical pyramidal cells in the temporal cortex, the CA1 pyramidal neurons and the cerebellum granular neurons. Belongs to the protein kinase superfamily. CK1 Ser/Thr protein kinase family.