Oocyte-specific protein tyrosine kinase that phosphorylates and inhibits CDK1/CDC2 and acts as a key regulator of meiosis during both prophase I and metaphase II (PubMed:29606300). Required to maintain meiotic arrest in oocytes during the germinal vesicle (GV) stage, a long period of quiescence at dictyate prophase I, by phosphorylating CDK1 at 'Tyr-15', leading to inhibit CDK1 activity and prevent meiotic reentry. Also required for metaphase II exit during egg activation by phosphorylating CDK1 at 'Tyr-15', to ensure exit from meiosis in oocytes and promote pronuclear formation (By similarity). ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Expressed in oocytes (at protein level) (PubMed:29606300). May also be expressed in testis (PubMed:11029659). Phosphorylated on serine residues (PubMed:29606300). Phosphorylation leads to increase its activity (By similarity). The disease is caused by variants affecting the gene represented in this entry. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. WEE1 subfamily.