protein kinase

A protein kinase is a kinase enzyme that modifies other proteins by chemically adding phosphate groups to them (phosphorylation). This class of protein is further separated into subsets such as PKC alpha, PKC beta, and PKC gamma, each with specific functions. Phosphorylation usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins. Up to 30% of all proteins may be modified by kinase activity, and kinases are known to regulate the majority of cellular pathways, especially those involved in signal transduction, the transmission of signals within the cell. The human genome contains about 500 protein kinase genes; they constitute about 2% of all eukaryotic genes.
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Protein kinase /pro·tein ki·nase/ an enzyme that catalyzes the phosphorylation of serine, threonine, or tyrosine groups in enzymes or other [more]Protein kinase - Community and Resources