What does phosphokinase mean?
A phosphokinase is an enzyme that catalyses phosphorylation, the attachment of a phosphate group to a molecule. The phosphate is generally transferred from ATP, the cell's principal energy-carrying molecule, to a protein or other substrate. This modification can alter a molecule's shape, activity, stability, or location, making phosphokinases central to cellular signalling and metabolic regulation. Well-known examples include protein kinases involved in growth, division, and communication. The term belongs mainly to biochemistry, molecular biology, medicine, and genetics. Although “phosphotransferase” is sometimes used more broadly, phosphokinase specifically identifies an enzyme that uses ATP to carry out phosphorylation. In scientific prose, the name is often qualified by the molecule affected or the pathway involved, as in “protein phosphokinase” or “phosphokinase activity.”
nounA phosphokinase is an enzyme that catalyses the transfer of a phosphate group, usually from ATP, to another molecule, thereby phosphorylating that substrate. Such enzymes are important in cellular energy metabolism, signalling, and regulation.
- An enzyme that catalyses the phosphorylation of a substrate, normally using ATP as the phosphate donor.
"The activated phosphokinase transferred a phosphate group to the target protein, changing its activity."
"Researchers measured the phosphokinase activity in the patient's blood samples."
"This mutation prevents the phosphokinase from adding phosphate to its usual cellular target."
The plural refers to multiple phosphokinase enzymes or multiple distinct types of phosphokinase.
"Several phosphokinases regulate the cell cycle."
Phosphokinases are molecular switchboards: by adding a phosphate tag, they can instantly change a protein's activity.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does phosphokinase come from?
Phosphokinase is a compound formed from phospho-, a combining form associated with phosphorus and phosphate, and kinase, a term based on the Greek kinesis, meaning movement. The phospho- element ultimately relates to Greek phōs, meaning light, through phosphoros, the ancient name for the element phosphorus. Together, the elements describe an enzyme involved in the enzymatic transfer of phosphate.
How phosphokinase is actually used
The term is primarily used in biochemistry and molecular biology. It is most often encountered as a component in the names of specific enzymes, rather than as an everyday word.
Easily confused with phosphokinase
A kinase is a broader term for an enzyme that transfers a phosphate group from ATP to a substrate, whereas phosphokinase emphasizes this ATP-dependent phosphotransfer activity.