Background of the antigen
CDK5 (Cyclin Dependent Kinase 5) is serine/threonine kinase involved in synaptic regulation and neuronal development; phosphorylates synaptic protein Pctaire1; regulates acetylcholine receptor expression. CDK5 is a member of the cyclindependent kinase family of serine/threonine kinases. It is present in numerous mammalian tissues including kidney, testes, and ovary. Its activity is detected almost exclusively in brain extracts. Neuronal and muscle cells contain the highest amount of this protein. Similar to other Cdks, monomeric Cdk5 displays no enzymatic activity, but Cdk5 is not activated by cyclins. Instead, the p35 protein, which is expressed solely in the brain, activates Cdk5. Cdk5 interacts with D1 and D3 type G1 cyclins and can phosphorylate histone H1, TAU, MAP2 and NF-H and NF-M. Cdk5 activity is involved in terminal differentiation of neurons and muscle cells.