Protein kinase which phosphorylates ESR1 (in vitro) and protects it against proteasomal degradation. May also regulate ESR1 levels indirectly via a PKC-AKT-FOXO3 pathway where it decreases the activity of PKC and the phosphorylation of AKT, thereby increasing binding of transcriptional activator FOXO3 to the ESR1 promoter and increasing ESR1 transcription (PubMed:21602804). Involved in endocytic trafficking of N-methyl-D-aspartate receptors (NMDAR) in neurons (By similarity). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Interacts with ESR1 (PubMed:21602804). Interacts with AP-2 complex subunit alpha (By similarity). Punctate pattern in cell projections. Belongs to the protein kinase superfamily. Tyr protein kinase family. Extended N-terminus.