Inositol monophosphatase 2 explained

Inositol monophosphatase 2 is a 32 kDa enzyme that in humans is encoded by the IMPA2 gene.^{[1] [2]} IMPA2 dephosphorylates myo-inositol monophosphate to myo-inositol.

The function of IMPA2 appears to be similar to IMPA1 within tissues; however, the genes are expressed differently in various tissues with IMPA2 expressed at the highest level in certain tissues of the brain and the lumen of the kidney. IMPA2 exists as a homodimer within cells and cannot form heterodimers with IMPA1.^[3]

Further reading

• Bonaldo MF, Lennon G, Soares MB . Normalization and subtraction: two approaches to facilitate gene discovery. . Genome Res. . 6 . 9 . 791–806 . 1997 . 8889548 . 10.1101/gr.6.9.791 . free .
• Yoshikawa T . Genomic structure and novel variants of myo-inositol monophosphatase 2 (IMPA2) . Mol. Psychiatry . 5 . 2 . 165–71 . 2000 . 10822344 . 10.1038/sj.mp.4000688 . Padigaru M . Karkera JD . Sharma . M . Berrettini . W H . Esterling . L E . Detera-Wadleigh . S D . 25662931 .
• Sjøholt G . A human myo-inositol monophosphatase gene (IMPA2) localized in a putative susceptibility region for bipolar disorder on chromosome 18p11.2: genomic structure and polymorphism screening in manic-depressive patients . Mol. Psychiatry . 5 . 2 . 172–80 . 2000 . 10822345 . 10.1038/sj.mp.4000681 . Gulbrandsen AK . Løvlie R . Berle . JØ . Molven . A . Steen . V M . 21428994 .
• Yoon IS . Altered IMPA2 gene expression and calcium homeostasis in bipolar disorder . Mol. Psychiatry . 6 . 6 . 678–83 . 2002 . 11673796 . 10.1038/sj.mp.4000901 . Li PP . Siu KP . Kennedy . J L . Cooke . R G . Parikh . S V . Warsh . J J . 26050322 .
• Strausberg RL . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . Feingold EA . Grouse LH . Derge . JG . Klausner . RD . Collins . FS . Wagner . L . Shenmen . CM . Schuler . GD . 2002PNAS...9916899M . free .
• Azzouz TN, Schumperli D . Evolutionary conservation of the U7 small nuclear ribonucleoprotein in Drosophila melanogaster . RNA . 9 . 12 . 1532–41 . 2004 . 14624008 . 10.1261/rna.5143303 . 1370506 .
• Sjøholt G . Examination of IMPA1 and IMPA2 genes in manic-depressive patients: association between IMPA2 promoter polymorphisms and bipolar disorder . Mol. Psychiatry . 9 . 6 . 621–9 . 2005 . 14699425 . 10.1038/sj.mp.4001460 . Ebstein RP . Lie RT . Berle . J Ø . Mallet . J . Deleuze . J F . Levinson . D F . Laurent . C . Mujahed . M . 28747842 .
• Gerhard DS . The Status, Quality, and Expansion of the NIH Full-Length cDNA Project: The Mammalian Gene Collection (MGC) . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 . Wagner L . Feingold EA . Shenmen . CM . Grouse . LH . Schuler . G . Klein . SL . Old . S . Rasooly . R .
• Nakayama J . Linkage and association of febrile seizures to the IMPA2 gene on human chromosome 18 . Neurology . 63 . 10 . 1803–7 . 2005 . 15557493 . 10.1212/01.wnl.0000144499.34164.e0. Yamamoto N . Hamano K . Iwasaki . N . Ohta . M . Nakahara . S . Matsui . A . Noguchi . E . Arinami . T . 20201724 .
• Ohnishi T . Spatial expression patterns and biochemical properties distinguish a second myo-inositol monophosphatase IMPA2 from IMPA1 . J. Biol. Chem. . 282 . 1 . 637–46 . 2007 . 17068342 . 10.1074/jbc.M604474200 . Ohba H . Seo KC . Im . J. . Sato . Y. . Iwayama . Y. . Furuichi . T. . Chung . S.-K. . Yoshikawa . T. . free .
• Ohnishi T . A promoter haplotype of the inositol monophosphatase 2 gene (IMPA2) at 18p11.2 confers a possible risk for bipolar disorder by enhancing transcription . Neuropsychopharmacology . 32 . 8 . 1727–37 . 2007 . 17251911 . 10.1038/sj.npp.1301307 . Yamada K . Ohba H . Iwayama . Yoshimi . Toyota . Tomoko . Hattori . Eiji . Inada . Toshiya . Kunugi . Hiroshi . Tatsumi . Masahiko . free .
• Arai R . Crystal structure of human myo-inositol monophosphatase 2, the product of the putative susceptibility gene for bipolar disorder, schizophrenia, and febrile seizures . Proteins . 67 . 3 . 732–42 . 2007 . 17340635 . 10.1002/prot.21299 . Ito K . Ohnishi T . Ohba . Hisako . Akasaka . Ryogo . Bessho . Yoshitaka . Hanawa-Suetsugu . Kyoko . Yoshikawa . Takeo . Shirouzu . Mikako . 46602105 .
• Blair MA, Ma S, Abou-Khalil B, Hedera P . Genetic variants in the IMPA2 gene do not confer increased risk of febrile seizures in Caucasian patients . Eur. J. Neurol. . 14 . 4 . 424–7 . 2007 . 17388992 . 10.1111/j.1468-1331.2007.01702.x . 36906656 .

Notes and References

1. Yoshikawa T, Turner G, Esterling LE, Sanders AR, Detera-Wadleigh SD . A novel human myo-inositol monophosphatase gene, IMP.18p, maps to a susceptibility region for bipolar disorder . Mol Psychiatry . 2 . 5 . 393–97 . Nov 1997 . 9322233 . 10.1038/sj.mp.4000325 . 24336959 .
2. Web site: Entrez Gene: IMPA2 inositol(myo)-1(or 4)-monophosphatase 2.
3. Ohnishi T, Ohba H, Seo KC, Im J, Sato Y, Iwayama Y, Furuichi T, Chung SK, Yoshikawa T . Spatial expression patterns and biochemical properties distinguish a second myo-inositol monophosphatase IMPA2 from IMPA1 . J. Biol. Chem. . 282 . 1 . 637–46 . January 2007 . 17068342 . 10.1074/jbc.M604474200 . free .