2016-2017 Faculty Research Grant

Peter Lyons (Biology)

Expression profile of carboxypeptidase O in cells, in tissues, and in organs.

Carboxypeptidases are enzymes necessary for the digestion of proteins and peptides throughout the body. To avoid uncontrolled digestion, the regulation of these enzymes is critical. One important means of regulation is through the control of gene expression – the process by which a gene produces a functional product. For example, while the human genome contains 25 carboxypeptidase genes, only a handful are expressed in any one tissue at a time. One of these genes is carboxypeptidase O (CPO), a membrane-anchored enzyme that removes acidic amino acids from the ends of protein substrates.

To better understand the physiological role of CPO, we wish to discover where CPO is expressed, at the level of organs and tissues and cells. We will do this by investigating CPO protein and mRNA levels in all organs of the thirteen-lined ground squirrel or eastern chipmunk using western blotting and quantitative PCR techniques. We will then focus on the expression patterns of CPO within tissues of the kidney, previously found to express high levels of CPO. Finally we will investigate the role of one particular part of CPO (its C-terminal end) in the efficient expression of CPO within cultured cells. Altogether, our study will use a range of techniques from histological to molecular to explore the expression of CPO and to support the training of a number of undergraduate students.