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Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).
Inositol monophosphatase (E.C. 3.1.3.25, IMPase, myo-inositol-1(or 4)-phosphate phosphohydrolase) is a magnesium-dependent homodimer which hydrolyses myo-inositol monophosphate to generate myo-inositol and phosphate. Glycerol may be a physiological phosphate acceptor. Li+ is a nonselective un-competitive inhibitor more potent at IMPase 1 (pKi ca. 3.5, [3]; pIC50 3.2, [4]) than IMPase 2 (pIC50 1.8-2.1, [4]). IMPase activity may be inhibited competitively by L690330 (pKi 5.5, [3]), although the enzyme selectivity is not yet established.
IMPase 1
C
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IMPase 2 C Show summary » |
Database page citation:
Inositol monophosphatase. Accessed on 06/12/2019. IUPHAR/BPS Guide to PHARMACOLOGY, http://www.guidetopharmacology.org/GRAC/FamilyDisplayForward?familyId=282.
Concise Guide to PHARMACOLOGY citation:
Alexander SPH, Fabbro D, Kelly E, Mathie A, Peters JA, Veale EL, Armstrong JF, Faccenda E, Harding SD, Pawson AJ, Sharman JL, Southan C, Davies JA; CGTP Collaborators. (2019) The Concise Guide to PHARMACOLOGY 2019/20: Enzymes. Br J Pharmacol. 176 Issue S1: S297-S396.
Polymorphisms in either of the genes encoding these enzymes have been linked with bipolar disorder [5-7]. Disruption of the gene encoding IMPase 1, but not IMPase 2, appears to mimic the effects of Li+ in mice [1-2].