inositol-1,4,5-trisphosphate 5-phosphatase activity
Definition
Target type: molecularfunction
Catalysis of the reaction: 1D-myo-inositol 1,4,5-trisphosphate + H2O = 1D-myo-inositol 1,4-bisphosphate + phosphate. [EC:3.1.3.56, RHEA:19797]
Inositol-1,4,5-trisphosphate 5-phosphatase activity is a crucial enzymatic process involved in the regulation of intracellular calcium signaling. This enzyme catalyzes the hydrolysis of the 5-phosphate group of inositol 1,4,5-trisphosphate (IP3), a second messenger molecule that plays a vital role in triggering the release of calcium from intracellular stores. IP3 is generated from the cleavage of phosphatidylinositol 4,5-bisphosphate (PIP2) by phospholipase C (PLC) in response to various stimuli, including hormones, neurotransmitters, and growth factors.
Upon its production, IP3 diffuses to the endoplasmic reticulum (ER), where it binds to specific IP3 receptors, leading to the opening of calcium channels and the release of calcium into the cytoplasm. This calcium surge triggers a cascade of cellular events, including muscle contraction, secretion, and gene expression.
The action of inositol 1,4,5-trisphosphate 5-phosphatase is to dephosphorylate IP3, converting it to inositol 1,4-bisphosphate (IP2). This dephosphorylation reaction effectively terminates the signaling activity of IP3, reducing its ability to bind to IP3 receptors and trigger calcium release. Therefore, inositol 1,4,5-trisphosphate 5-phosphatase acts as a crucial negative regulator of IP3-mediated calcium signaling, ensuring the proper termination of this signaling pathway.
The regulation of inositol 1,4,5-trisphosphate 5-phosphatase activity is critical for maintaining cellular homeostasis and normal cell function. Aberrant activity of this enzyme has been implicated in a variety of human diseases, including cancer, diabetes, and neurodegenerative disorders.'
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Proteins (4)
| Protein | Definition | Taxonomy |
|---|---|---|
| Inositol polyphosphate-5-phosphatase A | An inositol polyphosphate-5-phosphatase A that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q14642] | Homo sapiens (human) |
| Synaptojanin-1 | A synaptojanin-1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O43426] | Homo sapiens (human) |
| Inositol polyphosphate-5-phosphatase A | An inositol polyphosphate-5-phosphatase A that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q14642] | Homo sapiens (human) |
| Synaptojanin-1 | A synaptojanin-1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:O43426] | Homo sapiens (human) |
Compounds (8)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| epicatechin gallate | (-)-epicatechin-3-O-gallate : A gallate ester obtained by formal condensation of the carboxy group of gallic acid with the (3R)-hydroxy group of epicatechin. A natural product found in Parapiptadenia rigida. epicatechin gallate: a steroid 5alpha-reductase inhibitor; RN given refers to the (cis)-isomer; structure given in first source; isolated from green tea | catechin; gallate ester; polyphenol | EC 3.2.1.1 (alpha-amylase) inhibitor; EC 3.2.1.20 (alpha-glucosidase) inhibitor; metabolite |
| ampelopsin | (+)-dihydromyricetin : An optically active form of dihydromyricetin having (2R,3R)-configuration. ampelopsin: hepatoprotective agent; isolated from Hovenia dulcis; RN given for (2R-trans)-isomer; structure in first source | dihydromyricetin; secondary alpha-hydroxy ketone | antineoplastic agent; antioxidant; metabolite |
| inositol 1,4,5-trisphosphate | Inositol 1,4,5-Trisphosphate: Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4,5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1,4,5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell's endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin. | myo-inositol trisphosphate | mouse metabolite |
| epiafzelechin | (-)-epiafzelechin : A catechin derivative having (2R,3R)-configuration. epiafzelechin: antioxidant; 3'-deoxy form of epicatechin; structure in first source | catechin | plant metabolite |
| pyrvinium | pyrvinium : A quinolinium ion that is 1-methylquinolinium substituted by dimethylamino group at position 6 and a (E)-2-(2,5-dimethyl-1-phenyl-1H-pyrrol-3-yl)ethenyl at position 2. It is a anthelminthic drug active against pinworms. The salts of pyrvinium can also be used as anticancer agents. pyrvinium: RN given refers to parent cpd; synonyms vanquin & vankin refer to pamoate[2:1]; structure in Merck Index, 9th ed, #7810 | quinolinium ion | anthelminthic drug; antineoplastic agent |
| trans-2,3',4,5'-tetrahydroxystilbene | trans-2,3',4,5'-tetrahydroxystilbene: hydroxystilbene oxyresveratrol | stilbenoid | |
| chlorhexidine | chlorhexidine : A bisbiguanide compound with a structure consisting of two (p-chlorophenyl)guanide units linked by a hexamethylene bridge. Chlorhexidine: A disinfectant and topical anti-infective agent used also as mouthwash to prevent oral plaque. | biguanides; monochlorobenzenes | antibacterial agent; antiinfective agent |
| eriodictyol 7-O-beta-D-glucopyranoside | beta-D-glucoside; flavanone glycoside; monosaccharide derivative; trihydroxyflavanone | plant metabolite; radical scavenger |