Protease-activated receptor

The protease specificities, expression patterns, and functions of each PAR vary across a range of tissues and cell types.

[4] When scientists were researching the process of blood clotting in the late 1980s, they made the discovery of protease-activated receptors (PARs).

A novel protein that was activated by thrombin, a crucial part of the clotting cascade, was discovered by a research team at the University of California, San Francisco in 1991.

Protease activated receptors are integral membrane proteins that are coupled to G-proteins and are activated by proteolytic cleavage of the amino terminal sequence that exposes a new N-terminal sequence functions as a tethered ligand, which bind a conserved region on extracellular loop 2 (ECL2).

On the other hand, PARs can be specifically cleaved and irreversibly activated even by exogenous proteases originated from insects, bacteria or plants and fungi.

In this sense, here we report that TFF3 isolated from human breast milk activates PAR-2 receptors of intestinal epithelial cells HT-29.

PARs play a role in a multitude of physiological processes such as hemostasis, thrombosis, inflammation, and pain sensation.