Proline Rich Protein 4, Lacrimal (PRR4)

Proline-rich protein 4 is a protein encoded by the PRR4 gene.Lacrimal proline rich protein is a member of the proline-rich protein family which lacks a conserved repetitive domain. It may have a role in protective functions in the eye.Two alternatively spliced transcript variants that encode different proteins have been described for this gene.

The deduced 134-amino acid, 13.5-kD protein shares 45.5% sequence similarity with PRH1. It contains a 16-amino acid signal sequence, 21% proline residues, and an acidic N-terminal region. Southern blot analysis showed that LPRP is a single copy gene.Abundantly expressed in lacrimal gland where it is found in the acinar cells but not in the intralobular ducts. Also found in the submandibular gland, the parotid and sublingual glands.