Alternative titles; symbols
HGNC Approved Gene Symbol: PI15
Cytogenetic location: 8q21.13 Genomic coordinates (GRCh38) : 8:74,824,534-74,855,029 (from NCBI)
Koshikawa et al. (1996) identified PI15, which they called P25TI, as a trypsin inhibitor secreted by human glioblastoma cells. Yamakawa et al. (1998) cloned a PI15 cDNA by nested PCR from glioma and lymphocyte cDNA libraries. The deduced 258-amino acid protein has a predicted N-terminal signal sequence, a single N-glycosylation site, and an RRKR cleavage site. The mature secreted protein is predicted to contain 198-amino acids and to have a calculated molecular mass of about 23 kD. N-terminal sequencing of PI15 secreted from glioma cells confirmed cleavage of a prosequence. The purified protein shows an apparent molecular mass of 25 kD by SDS-PAGE. PCR analysis revealed expression in human brain, placenta, and lymphocyte cDNA. Northern blot analysis detected no expression in human tissues, presumably due to low levels of the protein, but did detect expression of a 6-kb transcript in glioblastoma and neuroblastoma cell lines.
Gross (2014) mapped the PI15 gene to chromosome 8q21.13 based on an alignment of the PI15 sequence (GenBank BC074931) with the genomic sequence (GRCh38).
Gross, M. B. Personal Communication. Baltimore, Md. 8/28/2014.
Koshikawa, N., Nakamura, T., Tsuchiya, N., Isaji, M., Yasumitsu, H., Umeda, M., Miyazaki, K. Purification and identification of a novel and four known serine proteinase inhibitors secreted by human glioblastoma cells. J. Biochem. 119: 334-339, 1996. [PubMed: 8882727] [Full Text: https://doi.org/10.1093/oxfordjournals.jbchem.a021244]
Yamakawa, T., Miyata, S., Ogawa, N., Koshikawa, N., Yasumitsu, H., Kanamori, T., Miyazaki, K. cDNA cloning of a novel trypsin inhibitor with similarity to pathogenesis-related proteins, and its frequent expression in human brain cancer cells. Biochim. Biophys. Acta 1395: 202-208, 1998. [PubMed: 9473672] [Full Text: https://doi.org/10.1016/s0167-4781(97)00149-8]