PRSS3

PRSS3, or protease, serine 3, is a protein-coding gene in humans that encodes trypsin-3, a member of the trypsin family of serine proteases. It belongs to the S1 family and shares the classical catalytic triad essential for peptide bond hydrolysis. The mature enzyme is typically secreted as a zymogen from pancreatic acinar cells and activated by proteolytic processing in the digestive tract, contributing to protein digestion by cleaving peptide bonds after basic residues such as lysine or arginine in dietary proteins. In humans, PRSS3 is expressed in the pancreas and at lower levels in other tissues; multiple transcript variants exist due to alternative splicing, producing distinct isoforms that may be secreted or intracellular.

In physiological contexts, PRSS3 participates in normal digestive processes and is regulated by protease inhibitors and zymogen activation cascades. In pathology, altered PRSS3 expression has been reported in several cancers, and some studies have linked high or aberrant PRSS3 levels with tumor progression or metastatic potential, though findings are not yet conclusive and the clinical significance remains under investigation. The gene and protein have been studied for potential diagnostic or therapeutic implications, but PRSS3 is not currently a standard biomarker.

Further research continues to refine understanding of PRSS3’s tissue distribution, regulation, substrate specificity, and role in disease. Database entries for human PRSS3 include gene and transcript annotations, protein family classifications, and cross-references to related serine proteases.