Several protein kinases are involved in cell cycle regulation. These include the serine/threonine kinases that transfer the phosphate groups of ATPs to different substrates. In this family of kinases, the most significant are the Cyclin-dependent kinase (Cdk), polo-like kinase (Plk), and Aurora kinase.
In addition to Cdk1, mitosis is controlled by other kinases including polo-like kinases (PLKs). PLKs participate in mitosis by being recruited to the mitotic spindle and activated by:
A. direct phosphorylation of PLKs by Cdk1
C. binding to a phosphorylated consensus sequence called polo boxes.
D. binding to phosphorylated Cdk1.
E. binding to cyclin.