Phosphoprotein phosphatase
- Phosphoprotein phosphatase
Phosphoprotein phosphatase is an enzyme which dephosphorylates certain phosphorylated proteins.
Overview of control of enzyme activity
The control of enzyme activity involves covalent modifications, including the addition of phosphate ions to serine, threonine and tyrosine residues in the enzyme. This addition is catalysed by protein kinases. The reverse reaction is carried out by phosphatase.
Effects of activation of phosphoprotein phosphatase
Phosphoprotein phosphatase is activated by the hormone insulin, which indicates that there is a high concentration of glucose in the blood. The enzyme then acts to dephosphorylate other enzymes, such as phosphorylase kinase, glycogen phosphorylase and glycogen synthase.
This leads to phosphorylase kinase and glycogen phosphorylase becoming inactive, while glycogen synthase is activated. As a result, glycogen synthesis is increased and glycogenolysis is decreased, and the net effect is for energy to enter and be stored inside the cell.
Mechanism
Phosphorylation involves the transfer of phosphate groups from ATP to the enzyme, the energy for which comes from hydrolysing ATP into ADP or AMP.
However, dephosphorylation releases phosphates into solution as free ions, because attaching them back to ATP would require energy input.
External links
*
*
Wikimedia Foundation.
2010.
Look at other dictionaries:
phosphoprotein phosphatase — phos·pho·pro·tein phos·pha·tase (fos″fo proґtēn fosґfə tās) [EC 3.1.3.16] an enzyme of the hydrolase class that catalyzes the cleavage of phosphoryl groups from phosphoproteins. Enzymes with this activity are involved in… … Medical dictionary
phosphoprotein phosphatase 1 — protein phosphatase 1 … Medical dictionary
Phosphatase PTEN — Bändermodell nach PDB … Deutsch Wikipedia
Protein tyrosine phosphatase — Protein tyrosine phosphatases (PTPs) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins. Protein tyrosine (pTyr) phosphorylation is a common post translational modification that can create novel… … Wikipedia
Dual-specificity phosphatase — is a form of phosphatase that can act upon tyrosine or serine/threonine residues.[1] References ^ MeSH Dual Specificity+Phosphatases … Wikipedia
MAPK phosphatase — MAPK phosphatases are a class of phosphatases. They are involved in MAP kinase signaling.[1] References ^ MeSH MAPK+Phosphatases … Wikipedia
protein phosphatase 1 — a specific phosphoprotein phosphatase (q.v.) that catalyzes the dephosphorylation of several enzymes involved in the regulation of glycogen metabolism: phosphorylase kinase, glycogen phosphorylase a, and glycogen synthase b. The enzyme activity… … Medical dictionary
protein phosphatase — pro·tein phos·pha·tase (proґtēn fosґfə tās) phosphoprotein phosphatase … Medical dictionary
Acidic leucine-rich nuclear phosphoprotein 32 family member A — Acidic (leucine rich) nuclear phosphoprotein 32 family, member A, also known as ANP32A, is a human gene. [cite web | title = Entrez Gene: ANP32A Acidic (leucine rich) nuclear phosphoprotein 32 family, member A| url =… … Wikipedia
CTD-Phosphatase — Masse/Länge Primärstruktur 961 Aminosäuren … Deutsch Wikipedia
