ID   IMPA1_XENLA             Reviewed;         285 AA.
AC   P29219;
DT   01-DEC-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-1992, sequence version 1.
DT   02-SEP-2026, entry version 129.
DE   RecName: Full=Inositol monophosphatase 1;
DE            Short=IMP 1;
DE            Short=IMPase 1;
DE            EC=3.1.3.25 {ECO:0000250|UniProtKB:P29218};
DE   AltName: Full=D-galactose 1-phosphate phosphatase {ECO:0000250|UniProtKB:P29218};
DE            EC=3.1.3.94 {ECO:0000250|UniProtKB:P29218};
DE   AltName: Full=Inositol-1(or 4)-monophosphatase 1;
GN   Name=impa1;
OS   Xenopus laevis (African clawed frog).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC   Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Xenopus.
OX   NCBI_TaxID=8355;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Oocyte;
RX   PubMed=1325777; DOI=10.1042/bj2860147;
RA   Wreggett K.A.;
RT   "Inositol monophosphatase is a highly conserved enzyme having localized
RT   structural similarity to both glycerol 3-phosphate dehydrogenase and
RT   haemoglobin.";
RL   Biochem. J. 286:147-152(1992).
CC   -!- FUNCTION: Phosphatase involved in the dephosphorylation of myo-inositol
CC       monophosphate to generate myo-inositol. Is also able to dephosphorylate
CC       scyllo-inositol-phosphate, myo-inositol 1,4-diphosphate, scyllo-
CC       inositol-1,3-diphosphate and scyllo-inositol-1,4-diphosphate. Also
CC       dephosphorylates in vitro other sugar-phosphates including D-galactose-
CC       1-phosphate, glucose-1-phosphate, glucose-6-phosphate, fructose-1-
CC       phosphate, beta-glycerophosphate and 2'-AMP. Responsible for the
CC       provision of inositol required for synthesis of phosphatidylinositol
CC       and polyphosphoinositides, and involved in maintaining normal brain
CC       function. Has been implicated as the pharmacological target for lithium
CC       Li(+) action in brain. {ECO:0000250|UniProtKB:P29218}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a myo-inositol phosphate + H2O = myo-inositol + phosphate;
CC         Xref=Rhea:RHEA:24056, ChEBI:CHEBI:15377, ChEBI:CHEBI:17268,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:84139; EC=3.1.3.25;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:24057;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=1D-myo-inositol 1-phosphate + H2O = myo-inositol + phosphate;
CC         Xref=Rhea:RHEA:27670, ChEBI:CHEBI:15377, ChEBI:CHEBI:17268,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58433; EC=3.1.3.25;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:27671;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=1D-myo-inositol 2-phosphate + H2O = myo-inositol + phosphate;
CC         Xref=Rhea:RHEA:44152, ChEBI:CHEBI:15377, ChEBI:CHEBI:17268,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:84142; EC=3.1.3.25;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:44153;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=1D-myo-inositol 3-phosphate + H2O = myo-inositol + phosphate;
CC         Xref=Rhea:RHEA:30739, ChEBI:CHEBI:15377, ChEBI:CHEBI:17268,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58401; EC=3.1.3.25;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:30740;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=1D-myo-inositol 4-phosphate + H2O = myo-inositol + phosphate;
CC         Xref=Rhea:RHEA:30735, ChEBI:CHEBI:15377, ChEBI:CHEBI:17268,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58469; EC=3.1.3.25;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:30736;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=1D-myo-inositol 5-phosphate + H2O = myo-inositol + phosphate;
CC         Xref=Rhea:RHEA:44156, ChEBI:CHEBI:15377, ChEBI:CHEBI:17268,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:84141; EC=3.1.3.25;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:44157;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=1D-myo-inositol 6-phosphate + H2O = myo-inositol + phosphate;
CC         Xref=Rhea:RHEA:44160, ChEBI:CHEBI:15377, ChEBI:CHEBI:17268,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:64841; EC=3.1.3.25;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:44161;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=scyllo-inositol 1-phosphate + H2O = scyllo-inositol +
CC         phosphate; Xref=Rhea:RHEA:82131, ChEBI:CHEBI:10642,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:43474, ChEBI:CHEBI:232087;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:82132;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=alpha-D-galactose 1-phosphate + H2O = D-galactose + phosphate;
CC         Xref=Rhea:RHEA:29315, ChEBI:CHEBI:4139, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58336; EC=3.1.3.94;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:29316;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=alpha-D-glucose 1-phosphate + H2O = D-glucose + phosphate;
CC         Xref=Rhea:RHEA:19933, ChEBI:CHEBI:4167, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58601;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:19934;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=D-glucose 6-phosphate + H2O = D-glucose + phosphate;
CC         Xref=Rhea:RHEA:16689, ChEBI:CHEBI:4167, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:61548;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:16690;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=beta-D-fructose 1-phosphate + H2O = D-fructose + phosphate;
CC         Xref=Rhea:RHEA:35603, ChEBI:CHEBI:15377, ChEBI:CHEBI:37721,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:138881;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:35604;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=glycerol 2-phosphate + H2O = glycerol + phosphate;
CC         Xref=Rhea:RHEA:13105, ChEBI:CHEBI:15377, ChEBI:CHEBI:17754,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58083;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:13106;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=adenosine 2'-phosphate + H2O = adenosine + phosphate;
CC         Xref=Rhea:RHEA:37343, ChEBI:CHEBI:15377, ChEBI:CHEBI:16335,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:77740;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:37344;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC         Evidence={ECO:0000250|UniProtKB:P29218};
CC   -!- ACTIVITY REGULATION: Inhibited by Li(+), Ca(2+) and Mn(2+), but also by
CC       Mg(2+) at concentrations above 3 mM. {ECO:0000250|UniProtKB:P29218}.
CC   -!- PATHWAY: Polyol metabolism; myo-inositol biosynthesis; myo-inositol
CC       from D-glucose 6-phosphate: step 2/2.
CC   -!- SUBUNIT: Homodimer. {ECO:0000250|UniProtKB:P29218}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250|UniProtKB:P29218}.
CC   -!- SIMILARITY: Belongs to the inositol monophosphatase superfamily.
CC       {ECO:0000305}.
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DR   EMBL; X65513; CAA46486.1; -; mRNA.
DR   PIR; S24343; S24343.
DR   AlphaFoldDB; P29219; -.
DR   SMR; P29219; -.
DR   OrthoDB; 10254945at2759; -.
DR   UniPathway; UPA00823; UER00788.
DR   Proteomes; UP000186698; Unplaced.
DR   GO; GO:0005737; C:cytoplasm; ISS:UniProtKB.
DR   GO; GO:0103026; F:fructose-1-phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0008877; F:glucose-1-phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0004346; F:glucose-6-phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0047954; F:glycerol-2-phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0008934; F:inositol monophosphate 1-phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0052832; F:inositol monophosphate 3-phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0052833; F:inositol monophosphate 4-phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0052834; F:inositol monophosphate phosphatase activity; ISS:UniProtKB.
DR   GO; GO:0031403; F:lithium ion binding; ISS:UniProtKB.
DR   GO; GO:0000287; F:magnesium ion binding; ISS:UniProtKB.
DR   GO; GO:0030145; F:manganese ion binding; ISS:UniProtKB.
DR   GO; GO:0006021; P:inositol biosynthetic process; IEA:UniProtKB-UniPathway.
DR   GO; GO:0046854; P:phosphatidylinositol phosphate biosynthetic process; IEA:InterPro.
DR   GO; GO:0007165; P:signal transduction; IBA:GO_Central.
DR   CDD; cd01639; IMPase; 1.
DR   FunFam; 3.30.540.10:FF:000004; Inositol-1-monophosphatase; 1.
DR   FunFam; 3.40.190.80:FF:000002; Inositol-1-monophosphatase; 1.
DR   Gene3D; 3.40.190.80; -; 1.
DR   Gene3D; 3.30.540.10; Fructose-1,6-Bisphosphatase, subunit A, domain 1; 1.
DR   InterPro; IPR033942; IMPase.
DR   InterPro; IPR020583; Inositol_monoP_metal-BS.
DR   InterPro; IPR020552; Inositol_monoPase_Li-sen.
DR   InterPro; IPR000760; Inositol_monophosphatase-like.
DR   InterPro; IPR020550; Inositol_monophosphatase_CS.
DR   PANTHER; PTHR20854; INOSITOL MONOPHOSPHATASE; 1.
DR   PANTHER; PTHR20854:SF26; INOSITOL MONOPHOSPHATASE 1; 1.
DR   Pfam; PF00459; Inositol_P; 1.
DR   PRINTS; PR00377; IMPHPHTASES.
DR   PRINTS; PR00378; LIIMPHPHTASE.
DR   SUPFAM; SSF56655; Carbohydrate phosphatase; 1.
DR   PROSITE; PS00629; IMP_1; 1.
DR   PROSITE; PS00630; IMP_2; 1.
PE   2: Evidence at transcript level;
KW   Cytoplasm; Hydrolase; Lithium; Magnesium; Metal-binding;
KW   Reference proteome.
FT   CHAIN           1..285
FT                   /note="Inositol monophosphatase 1"
FT                   /id="PRO_0000142518"
FT   BINDING         73
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         73
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         93
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         93
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         95..98
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         95
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="1"
FT                   /ligand_note="catalytic"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         96
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         198..200
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         217
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         224
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
FT   BINDING         224
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P29218"
SQ   SEQUENCE   285 AA;  30729 MW;  34E9CD9A99231292 CRC64;
     MEDRWQECMD FLAVSIARKA GSVVCAALKE DVSIMVKTSL APADLVTATD QKVEEMIISS
     IKEKYPSHSF IGEESVAAGA GSTLTDNPTW IIDPIDGTTN FVHRFPFVAV SIGFAVHKQV
     EFGVVYSCVE DKMYTGRKGK GSFCNGQKLQ VSGQKDITKS MIITELGSNR NPEFIKTVSL
     SNMERLLCIP IHGIRAVGTA AVNMCLVATG GADAYYEMGL HCWDMAAASV IVTEAGGTIL
     DATGGLFDLM SCRIISASSR EIAERIAKEL QIIPLERDDG KSTNS
//