Polarity factor involved in localization of polarized growth and cytokinesis (PubMed:11230130, PubMed:11950884, PubMed:14663827, PubMed:17077120). Forms an intracellular gradient that serves to measure cell length and control mitotic entry (PubMed:19474792, PubMed:19474789, PubMed:21703453, PubMed:24047646). Controls the timing of mitotic commitment by regulating the inhibitory impact of cdr1/cdr2 on wee1 activity (PubMed:19474792, PubMed:22684255, PubMed:24316795). Directly phosphorylates the tail of cdr2 which inhibits cdr2 activation by ssp1 (PubMed:19474792, PubMed:24508166). Cdr2 phosphorylation by pom1 also modulates cdr2 association with membranes and inhibits cdr2 interaction with mid1, reducing its clustering ability, possibly via the down-regulation of cdr2 kinase activity (PubMed:24982431). Acts as a negative regulator of mid1 distribution, excluding mid1 from non-growing ends, which prevents division-septum assembly at the cell ends (PubMed:17140794, PubMed:17077120, PubMed:17543869). The pom1 polar gradient also mediates mitotic entry by regulating cdk1 (PubMed:19474789). Plays an essential role in proper localization and phosphorylation of a GAP for cdc42, rga4, which ensures bipolar localization of GTP-bound, active cdc42 involved in F-actin formation (PubMed:18328707). Phosphorylates multiple other substrates that function in polarized cell growth, including tea4, mod5, pal1, the Rho GAP rga7, and the Arf GEF syt22 (PubMed:25720772). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Interacts with rga4 (PubMed:18328707). Interacts with tea4; this interaction triggers pom1 plasma membrane association (PubMed:21703453). Forms an intracellular gradient that serves to measure cell length and control mitotic entry (PubMed:19474792, PubMed:19474789, PubMed:21703453, PubMed:22342545, PubMed:26150232). Localized to the septum at the time of cytokinesis (PubMed:14663827). Tea4 recruits pom1 to the cell cortex from where it then moves laterally at the plasma membrane, which it binds through a basic region exhibiting direct lipid interaction (PubMed:21703453). Pom1 autophosphorylates in this region to lower lipid affinity and promote membrane release (PubMed:21703453). Tea4 triggers pom1 plasma membrane association by promoting its dephosphorylation through the protein phosphatase dis2 (PubMed:21703453). Autophosphorylates at the cell cortex to lower lipid affinity and promote membrane release (PubMed:21703453, PubMed:26150232). Dephosphorylation by dis2, regulated by tea4, triggers membrane association (PubMed:21703453). Belongs to the protein kinase superfamily. CMGC Ser/Thr protein kinase family. MNB/DYRK subfamily.