Protein serine/threonine phosphatase
protein-serine/threonine phosphatase | |||
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Identifiers | |||
EC no. | 3.1.3.16 | ||
CAS no. | 9025-75-6 | ||
Databases | |||
IntEnz | IntEnz view | ||
BRENDA | BRENDA entry | ||
ExPASy | NiceZyme view | ||
KEGG | KEGG entry | ||
MetaCyc | metabolic pathway | ||
PRIAM | profile | ||
PDB structures | RCSB PDB PDBe PDBsum | ||
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Protein serine/threonine phosphatase (PSP)[1] is a form of phosphoprotein phosphatase that acts upon phosphorylated serine/threonine residues.
Serine and threonine phosphates are stable under physiological conditions, so a phosphatase enzyme has to remove the phosphate to reverse the regulation signal. Ser/Thr-specific protein phosphatases are regulated partly by their location within the cell and by specific inhibitor proteins.
Serine and threonine are amino acids which have similar side-chain compositions that contain a hydroxyl group and thus can be phosphorylated by enzymes called serine/threonine protein kinases. The addition of the phosphate group can be reversed by enzymes called serine/threonine phosphatases. The addition and removal of phosphate groups regulates many cellular pathways involved in cell proliferation, programmed cell death (apoptosis), embryonic development, and cell differentiation.
Examples[]
There are several known groups with numerous members in each:
- PPP1 (α, β, γ1, γ2)
- PPP2 (formerly 2A)
- PPP3 (formerly 2b, also known as calcineurin)
- PPP2C
- PPP4
- PPP5
- PPP6
(links are to the catalytic subunit)
All but PPP2C have sequence homology in the catalytic domain, but differ in substrate specificity.[citation needed]
References[]
- ^ Shi Y (October 2009). "Serine/threonine phosphatases: mechanism through structure". Cell. 139 (3): 468–84. doi:10.1016/j.cell.2009.10.006. PMID 19879837.
External links[]
- EC 3.1.3
- Hydrolase stubs