Enzymes
| UniProtKB help_outline | 1,101 proteins |
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- Name help_outline 1D-myo-inositol 1,3,4-trisphosphate Identifier CHEBI:58414 (Beilstein: 4896056) help_outline Charge -6 Formula C6H9O15P3 InChIKeyhelp_outline MMWCIQZXVOZEGG-MLQGYMEPSA-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 7 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 1D-myo-inositol 1,3,4,5,6-pentakisphosphate Identifier CHEBI:57733 (Beilstein: 7685231) help_outline Charge -10 Formula C6H7O21P5 InChIKeyhelp_outline CTPQAXVNYGZUAJ-KXXVROSKSA-D SMILEShelp_outline O[C@@H]1[C@H](OP([O-])([O-])=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 9 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 1D-myo-inositol 3,4,5,6-tetrakisphosphate Identifier CHEBI:57539 (Beilstein: 5470008) help_outline Charge -8 Formula C6H8O18P4 InChIKeyhelp_outline MRVYFOANPDTYBY-UZAAGFTCSA-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 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 1D-myo-inositol 1,3,4,6-tetrakisphosphate Identifier CHEBI:57660 (Beilstein: 7071293) help_outline Charge -8 Formula C6H8O18P4 InChIKeyhelp_outline ZAWIXNGTTZTBKV-JMVOWJSSSA-F SMILEShelp_outline O[C@H]1[C@H](OP([O-])([O-])=O)[C@@H](OP([O-])([O-])=O)[C@@H](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
Cross-references
| RHEA:70263 | RHEA:70264 | RHEA:70265 | RHEA:70266 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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| MetaCyc help_outline |
Publications
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Integration of inositol phosphate signaling pathways via human ITPK1.
Chamberlain P.P., Qian X., Stiles A.R., Cho J., Jones D.H., Lesley S.A., Grabau E.A., Shears S.B., Spraggon G.
Inositol 1,3,4-trisphosphate 5/6-kinase (ITPK1) is a reversible, poly-specific inositol phosphate kinase that has been implicated as a modifier gene in cystic fibrosis. Upon activation of phospholipase C at the plasma membrane, inositol 1,4,5-trisphosphate enters the cytosol and is inter-converted ... >> More
Inositol 1,3,4-trisphosphate 5/6-kinase (ITPK1) is a reversible, poly-specific inositol phosphate kinase that has been implicated as a modifier gene in cystic fibrosis. Upon activation of phospholipase C at the plasma membrane, inositol 1,4,5-trisphosphate enters the cytosol and is inter-converted by an array of kinases and phosphatases into other inositol phosphates with diverse and critical cellular activities. In mammals it has been established that inositol 1,3,4-trisphosphate, produced from inositol 1,4,5-trisphosphate, lies in a branch of the metabolic pathway that is separate from inositol 3,4,5,6-tetrakisphosphate, which inhibits plasma membrane chloride channels. We have determined the molecular mechanism for communication between these two pathways, showing that phosphate is transferred between inositol phosphates via ITPK1-bound nucleotide. Intersubstrate phosphate transfer explains how competing substrates are able to stimulate each others' catalysis by ITPK1. We further show that these features occur in the human protein, but not in plant or protozoan homologues. The high resolution structure of human ITPK1 identifies novel secondary structural features able to impart substrate selectivity and enhance nucleotide binding, thereby promoting intersubstrate phosphate transfer. Our work describes a novel mode of substrate regulation and provides insight into the enzyme evolution of a signaling mechanism from a metabolic role. << Less
J. Biol. Chem. 282:28117-28125(2007) [PubMed] [EuropePMC]
This publication is cited by 4 other entries.