- The addition of a phosphate group to one or more sites on the protein, which alters the activity of the protein
- Usually exchanges hydroxyl R group with phosphate
- Switches proteins on → increases potential energy and ability for chemical work
- Protein phosphorylation involved with regulation of transcription, enzymes and TRKs
- The transfer of the phosphate group is catalyzed by the kinase enzyme
- Cells contain many different kinases that phosphorylate different targets
- The reverse: after a protein has been “activated”, the enzyme phosphatases switches them back into non-phosphorylated state by catalyzing removal of phosphates
Turns of kinase cascades