Enzymes
| UniProtKB help_outline | 428 proteins |
| Enzyme class help_outline |
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- Name help_outline 1D-myo-inositol 1,4,5,6-tetrakisphosphate Identifier CHEBI:57627 (Beilstein: 6682109) help_outline Charge -8 Formula C6H8O18P4 InChIKeyhelp_outline MRVYFOANPDTYBY-YORTWTKJSA-F SMILEShelp_outline O[C@H]1[C@@H](O)[C@@H](OP([O-])([O-])=O)[C@H](OP([O-])([O-])=O)[C@@H](OP([O-])([O-])=O)[C@@H]1OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,148 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 1D-myo-inositol 1,4,5-trisphosphate Identifier CHEBI:203600 (Beilstein: 4303027) help_outline Charge -6 Formula C6H9O15P3 InChIKeyhelp_outline MMWCIQZXVOZEGG-XJTPDSDZSA-H SMILEShelp_outline O[C@@H]1[C@H](O)[C@@H](OP([O-])([O-])=O)[C@H](OP([O-])([O-])=O)[C@@H](O)[C@@H]1OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 8 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline phosphate Identifier CHEBI:43474 Charge -2 Formula HO4P InChIKeyhelp_outline NBIIXXVUZAFLBC-UHFFFAOYSA-L SMILEShelp_outline OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 992 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:77147 | RHEA:77148 | RHEA:77149 | RHEA:77150 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Stable Isotopomers of myo-Inositol Uncover a Complex MINPP1-Dependent Inositol Phosphate Network.
Nguyen Trung M., Kieninger S., Fandi Z., Qiu D., Liu G., Mehendale N.K., Saiardi A., Jessen H., Keller B., Fiedler D.
The water-soluble inositol phosphates (InsPs) represent a functionally diverse group of small-molecule messengers involved in a myriad of cellular processes. Despite their centrality, our understanding of human InsP metabolism is incomplete because the available analytical toolset to characterize ... >> More
The water-soluble inositol phosphates (InsPs) represent a functionally diverse group of small-molecule messengers involved in a myriad of cellular processes. Despite their centrality, our understanding of human InsP metabolism is incomplete because the available analytical toolset to characterize and quantify InsPs in complex samples is limited. Here, we have synthesized and applied symmetrically and unsymmetrically <sup>13</sup>C-labeled <i>myo</i>-inositol and inositol phosphates. These probes were utilized in combination with nuclear magnetic resonance spectroscopy (NMR) and capillary electrophoresis mass spectrometry (CE-MS) to investigate InsP metabolism in human cells. The labeling strategy provided detailed structural information via NMR-down to individual enantiomers-which overcomes a crucial blind spot in the analysis of InsPs. We uncovered a novel branch of InsP dephosphorylation in human cells which is dependent on MINPP1, a phytase-like enzyme contributing to cellular homeostasis. Detailed characterization of MINPP1 activity in vitro and in cells showcased the unique reactivity of this phosphatase. Our results demonstrate that metabolic labeling with stable isotopomers in conjunction with NMR spectroscopy and CE-MS constitutes a powerful tool to annotate InsP networks in a variety of biological contexts. << Less
ACS Cent. Sci. 8:1683-1694(2022) [PubMed] [EuropePMC]
This publication is cited by 13 other entries.
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Molecular cloning and expression of a rat hepatic multiple inositol polyphosphate phosphatase.
Craxton A., Caffrey J.J., Burkhart W., Safrany S.T., Shears S.B.
The characterization of the multiple inositol polyphosphate phosphatase (MIPP) is fundamental to our understanding of how cells control the signalling activities of 'higher' inositol polyphosphates. We now describe our isolation of a 2.3 kb cDNA clone of a rat hepatic form of MIPP. The predicted a ... >> More
The characterization of the multiple inositol polyphosphate phosphatase (MIPP) is fundamental to our understanding of how cells control the signalling activities of 'higher' inositol polyphosphates. We now describe our isolation of a 2.3 kb cDNA clone of a rat hepatic form of MIPP. The predicted amino acid sequence of MIPP includes an 18 amino acid region that aligned with approximately 60% identity with the catalytic domain of a fungal inositol hexakisphosphate phosphatase (phytase A); the similarity encompassed conservation of the RHGXRXP signature of the histidine acid phosphatase family. A histidine-tagged, truncated form of MIPP was expressed in Escherichia coli and the enzymic specificity of the recombinant protein was characterized: Ins(1,3,4,5,6)P5 was hydrolysed, first to Ins(1,4,5,6)P4 and then to Ins(1,4,5)P3, by consecutive 3- and 6-phosphatase activities. Inositol hexakisphosphate was catabolized without specificity towards a particular phosphate group, but in contrast, MIPP only removed the beta-phosphate from the 5-diphosphate group of diphosphoinositol pentakisphosphate. These data, which are consistent with the substrate specificities of native (but not homogeneous) MIPP isolated from rat liver, provide the first demonstration that a single enzyme is responsible for this diverse range of specific catalytic activities. A 2.5 kb transcript of MIPP mRNA was present in all rat tissues that were examined, but was most highly expressed in kidney and liver. The predicted C-terminus of MIPP is comprised of the tetrapeptide SDEL, which is considered a signal for retaining soluble proteins in the lumen of the endoplasmic reticulum; the presence of this sequence provides a molecular explanation for our earlier biochemical demonstration that the endoplasmic reticulum contains substantial MIPP activity [Ali, Craxton and Shears (1993) J. Biol. Chem. 268, 6161-6167]. << Less
Biochem. J. 328:75-81(1997) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.