HGNC Approved Gene Symbol: PTPN9
Cytogenetic location: 15q24.2 Genomic coordinates (GRCh38) : 15:75,463,251-75,579,315 (from NCBI)
Gu et al. (1992) cloned a cDNA for a protein tyrosine phosphatase (PTPase), which they designated MEG2, by screening libraries of the MEG-01 megakaryocyte leukemia cell line and of human umbilical vein endothelial cells. The MEG2 cDNA encodes a 593-amino acid protein that has no apparent signal or transmembrane domains but does include a C-terminal region with a catalytic domain that shows 30-40% identity with other PTPases. The N-terminal 254 amino acids are about 28% identical to cellular retinaldehyde binding protein-1 (RLBP1; 180090) and 24% identical to the yeast protein SEC14p; the former is a carrier protein for 11-cis-retinaldehyde or 11-cis-retinol found in the retina and pineal gland, and the latter is a phosphatidylinositol transfer protein required for protein secretion from the Golgi apparatus. An approximately 4-kb RNA was detected on Northern blot analysis in a variety of cell lines, indicating widespread expression of the gene.
Gu et al. (1992) speculated that MEG2 may, like RLBP1 and SEC14p (601504), participate in the transfer of hydrophobic ligands or may be involved in Golgi-related functions. Recombinantly expressed MEG2 was shown to have PTPase activity.
Gross (2014) mapped the PTPN9 gene to chromosome 15q24.2 based on an alignment of the PTPN9 sequence (GenBank BC010863) with the genomic sequence (GRCh37).
Gross, M. B. Personal Communication. Baltimore, Md. 3/25/2014.
Gu, M., Warshawsky, I., Majerus, P. W. Cloning and expression of a cytosolic megakaryocyte protein-tyrosine-phosphatase with sequence homology to retinaldehyde-binding protein and yeast SEC14p. Proc. Nat. Acad. Sci. 89: 2980-2984, 1992. [PubMed: 1557404] [Full Text: https://doi.org/10.1073/pnas.89.7.2980]