Alternative titles; symbols
HGNC Approved Gene Symbol: MTMR12
Cytogenetic location: 5p13.3 Genomic coordinates (GRCh38): 5:32,227,007-32,312,939 (from NCBI)
Phosphatidylinositide 3-kinase (see PIK3R1; 171833)-derived, membrane-anchored phosphatidylinositides, such as phosphatidylinositol 3-phosphate (PtdIns(3)P), regulate diverse cellular processes. 3PAP functions as an adaptor subunit in a complex with an active PtdIns(3)P 3-phosphatase.
By screening for cDNAs with the potential to encode large proteins expressed in brain, Nagase et al. (2000) identified a cDNA encoding 3PAP, which they called KIAA1682. KIAA1682 encodes a deduced 775-amino acid protein. RT-PCR analysis detected moderate expression of KIAA1682 in all tissues tested.
By biochemical purification and microsequence analysis of the rat brain cytosolic 3Pap protein, followed by PCR with degenerate primers, screening of a K562 cDNA library, and RT-PCR, Nandurkar et al. (2001) obtained a cDNA encoding human 3PAP. Sequence analysis predicted that the 3PAP protein has homology to myotubularin but, like SBF1 (603560), lacks the HCX5R catalytic motif. Northern blot analysis revealed expression of 5.5- and 2.5-kb 3PAP transcripts that were prominent in brain, heart, kidney, liver, placenta, and lung. Immunoblot analysis showed expression of an 86-kD protein in various tissues and cell lines. Immunoprecipitation analysis indicated that platelet 3PAP, but not recombinant 3PAP, possesses lipid 3-phosphatase activity. Nandurkar et al. (2001) concluded that 3PAP is an adaptor subunit in a complex with an active PtdIns(3)P 3-phosphatase.
Using a human-rodent hybrid panel, Nagase et al. (2000) mapped the KIAA1682 gene to both chromosomes 5 and 11. The International Radiation Hybrid Mapping Consortium mapped the 3PAP gene to chromosome 5 (RH26387).
Nagase, T., Kikuno, R., Hattori, A., Kondo, Y., Okumura, K., Ohara, O. Prediction of the coding sequences of unidentified human genes. XIX. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro. DNA Res. 7: 347-355, 2000. [PubMed: 11214970] [Full Text: https://doi.org/10.1093/dnares/7.6.347]
Nandurkar, H. H., Caldwell, K. K., Whisstock, J. C., Layton, M. J., Gaudet, E. A., Norris, F. A., Majerus, P. W., Mitchell, C. A. Characterization of an adapter subunit to a phosphatidylinositol (3)P 3-phosphatase: identification of a myotubularin-related protein lacking catalytic activity. Proc. Nat. Acad. Sci. 98: 9499-9504, 2001. [PubMed: 11504939] [Full Text: https://doi.org/10.1073/pnas.171306098]