Wee1-like protein kinase <p>This group represents a Wee1-like protein kinase (<db_xref db="EC" dbkey="2.7.10.2"/>), which is a key regulator for G(2)-to-M progression. This enzyme phosphorylates Tyr15 on Cdc2 (cell division control protein 2) when Cdc2 is complexed to cyclin B1, which results in blocking the progression of cells into M phase [<cite idref="PUB00044669"/>]. As such, it negatively regulates the entry of a cell into mitosis (G2 to M transition) by protecting the nucleus from cytoplasmically activated cyclin B1-complexed Cdc2 before the onset of mitosis [<cite idref="PUB00042736"/>, <cite idref="PUB00044670"/>]. The activity of this enzyme increases during S and G2 phases and decreases at M phase when it is hyperphosphorylated; it is then ubiquitinated and degraded at the onset of G2/M phase.</p>