Casein Kinase type II (CK II) is a tetrameric enzyme of 130-150 kDa with α2β2 structure. The α subunit is catalytic and the β subunit is thought to have regulatory properties. CK II is expressed in the nucleus as well as in the cytoplasm and mitochondria. It has been implicated in a variety of cellular processes and is important for signaling pathways controlling growth division including mitosis, cellular transformation, and differentiation of cells. Several nuclear proteins, enzymes, and transcription factors serve as substrates for CK II. It was shown that some mitogens induce the activity of CK II.
The Casein Kinase II Assay Kit provides an easy method for measuring enzyme activity by an in vitrophosphorylation of the Casein Kinase II Substrate. This substrate is a peptide that is selective for CK II with no activity with CK I. It has a very high affinity for CK II and the highest Vmax compared to other peptide substrates.