Alternative titles; symbols
HGNC Approved Gene Symbol: PRSS22
Cytogenetic location: 16p13.3 Genomic coordinates (GRCh38) : 16:2,852,730-2,858,170 (from NCBI)
Members of the serine protease family, such as PRSS22, proteolytically activate or degrade proteins and are involved in many biologic processes, including embryonic development, immunity, and food digestion (Wong et al., 2001).
By searching an EST database for sequences similar to beta-I tryptase (191080) and TMT (TPSG1; 609341), followed by PCR of adult pancreas and fetal kidney cDNA libraries, Wong et al. (2001) cloned PRSS22, which they designated tryptase-epsilon. The deduced 317-amino acid protein contains an N-terminal hydrophobic leader peptide, followed by a propeptide sequence and the serine protease domain, which has the catalytic triad of histidine, aspartic acid, and serine. PRSS22 also has 2 cysteines that form a disulfide bond linking the propeptide and the catalytic domain following proteolytic activation, and it has an N-glycosylation site. PRSS22 lacks a number of residues required by other tryptases to form tetramers. RNA dot blot analysis detected abundant PRSS22 expression in adult esophagus and trachea, with lower levels in adult placenta, pancreas, prostate, and thyroid, and in fetal kidney and lung. There was little to no expression in other tissues examined. Enzymatically active PRSS22 was secreted from a human epithelial cell line and from transfected COS-7 cells. Western blot analysis detected PRSS22 at an apparent molecular mass of 37 kD, which reduced to about 33 kD following deglycosylation. Under nonreducing conditions, PRSS22 migrated at both 33 and 66 kD, indicating that it can form disulfide-linked homotypic dimers.
Using several synthetic chromogenic peptide substrates, Wong et al. (2001) found that the substrate specificity of recombinant PRSS22 expressed by insect cells was different than that shown by beta-I tryptase.
Wong et al. (2001) determined that the PRSS22 gene spans 5.3 kb. The upstream region contains a TATA box.
By genomic sequence analysis, Wong et al. (2001) mapped the PRSS22 gene within a 2.5-Mb region of chromosome 16p13.3 that contains several serine protease genes. The corresponding mouse tryptase locus resides at chromosome 17A3.3-B1.
Wong, G. W., Yasuda, S., Madhusudhan, M. S., Li, L., Yang, Y., Krilis, S. A., Sali, A., Stevens, R. L. Human tryptase epsilon (PRSS22), a new member of the chromosome 16p13.3 family of human serine proteases expressed in airway epithelial cells. J. Biol. Chem. 276: 49169-49182, 2001. [PubMed: 11602603] [Full Text: https://doi.org/10.1074/jbc.M108677200]