phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity
Definition
Target type: molecularfunction
1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4,5-trisphosphate) + H2O = 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4-bisphosphate) + phosphate. [EC:3.1.3.86, GOC:pf]
Phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity refers to the enzymatic removal of the phosphate group from the 5-position of phosphatidylinositol-3,4,5-trisphosphate (PIP3). PIP3 is a critical signaling molecule involved in various cellular processes, including cell growth, proliferation, survival, migration, and differentiation.
This phosphatase activity is catalyzed by a family of enzymes known as PTEN (phosphatase and tensin homolog deleted on chromosome ten) and SHIP (SH2-containing inositol 5-phosphatase). These enzymes play a crucial role in regulating the levels of PIP3 in cells, thereby influencing downstream signaling pathways.
The removal of the phosphate group from PIP3 by 5-phosphatases converts it into phosphatidylinositol-3,4-bisphosphate (PIP2). This conversion has significant implications for signaling pathways as it reduces the activity of downstream signaling molecules that are activated by PIP3, such as AKT/PKB and mTOR.
Specifically, 5-phosphatases regulate PIP3 levels in the following ways:
1. **Negative regulation of PI3K signaling:** PI3K (phosphoinositide 3-kinase) is a key enzyme responsible for the production of PIP3 from PIP2. By removing the phosphate group from PIP3, 5-phosphatases reduce the levels of PIP3, thereby attenuating PI3K signaling. This negative regulation is essential for maintaining proper cellular homeostasis.
2. **Modulation of downstream signaling cascades:** PIP3 serves as a docking site for various signaling proteins, including AKT/PKB and mTOR. These proteins are activated by PIP3 and subsequently initiate downstream signaling cascades involved in cell growth, proliferation, and survival. By decreasing PIP3 levels, 5-phosphatases dampen the activity of these signaling pathways.
3. **Fine-tuning cellular responses:** The precise levels of PIP3 are crucial for regulating cellular responses to various stimuli. 5-phosphatases contribute to this fine-tuning by adjusting the levels of PIP3, ensuring appropriate responses to internal and external signals.
In summary, phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase activity is essential for regulating cellular signaling by controlling the levels of PIP3. This enzymatic activity plays a crucial role in a variety of cellular processes, including cell growth, proliferation, survival, migration, and differentiation.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| Phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase 2 | A phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O15357] | Homo sapiens (human) |
| Phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase 2 | A phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O15357] | Homo sapiens (human) |
Compounds (6)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 2-(4-hydroxyphenyl)-5,6,7,8-tetrahydroxy-4H-1-benzopyran-4-one | 2-(4-hydroxyphenyl)-5,6,7,8-tetrahydroxy-4H-1-benzopyran-4-one : A pentahydroxyflavone that is flavone substituted by hydroxy groups at positions 5, 6, 7, 8, and 4' respectively. | pentahydroxyflavone | |
| inositol-1,3,4,5-tetrakisphosphate | 1D-myo-inositol 1,3,4,5-tetrakisphosphate : A myo-inositol tetrakisphosphate having the four phosphates placed in the 1-, 3-, 4- and 5-positions. inositol-1,3,4,5-tetrakisphosphate: for cpd without numerical locants of phosphate groups, index INOSITOL PHOSPHATES | inositol phosphate | |
| nsc-89199 | estramustine phosphate : A steroid phosphate which is the 17-O-phospho derivative of estramustine. | carbamate ester; organochlorine compound; steroid phosphate | |
| crizotinib | crizotinib : A 3-[1-(2,6-dichloro-3-fluorophenyl)ethoxy]-5-[1-(piperidin-4-yl)pyrazol-4-yl]pyridin-2-amine that has R configuration at the chiral centre. The active enantiomer, it acts as a kinase inhibitor and is used for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) Crizotinib: A piperidine and aminopyridine derivative that acts as an inhibitor of RECEPTOR PROTEIN-TYROSINE KINASES, including ANAPLASTIC LYMPHOMA KINASE (ALK) and HEPATOCYTE GROWTH FACTOR RECEPTOR (HGFR; c-Met). It is used in the treatment of NON-SMALL CELL LUNG CANCER. | 3-[1-(2,6-dichloro-3-fluorophenyl)ethoxy]-5-[1-(piperidin-4-yl)pyrazol-4-yl]pyridin-2-amine | antineoplastic agent; biomarker; EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor |
| as1949490 | |||
| galloflavin | galloflavin: structure in first source |