A major XXXX lacrimal gland mRNA encodes a new @entity1521 -rich protein family member.

@entity1 @entity1521 @entity67373
PURPOSE: To examine the existence of novel protein products of the @entity1 lacrimal gland. METHODS: cDNA clones corresponding to a highly abundant @entity1 lacrimal gland mRNA were isolated and sequenced. Tissue distribution of expression was studied by Northern blot analysis, RNase protection analysis, and in situ hybridization. RESULTS: A highly abundant 600-base mRNA was identified, and corresponding cDNA clones were isolated. The mRNA has a 134-residue open reading frame encoding a secreted protein of 13458 Da. This protein shows 45.5% similarity to @entity1 salivary acidic @entity1521 -rich protein PRP 1 and has a similar domain structure, but, unlike other members of the @entity1521 -rich protein family, it lacks a conserved repetitive domain. The lacrimal @entity1521 -rich protein is encoded by a single gene, designated as @entity67373 . Expression of @entity67373 was also detected in the @entity1 submandibular, von Ebners, sublingual, and parotid glands. @entity67373 was expressed in the acinar cells of the lacrimal gland, and in the submandibular gland expression of the @entity67373 and PRP 1 genes was localized to the serous acini and demilunes. CONCLUSIONS: The @entity1 lacrimal gland produces a previously unknown member of the @entity1521 -rich protein family. By analogy with other @entity1521 -rich proteins, this @entity67373 most likely mediates protective functions in the eye, such as modulation of the microflora. In contrast to other @entity1521 -rich protein genes, @entity67373 is expressed in the lacrimal acinar cells, and other anterior exocrine glands. @entity67373 should be a useful marker for @entity1 lacrimal gland acinar cell function in vitro.
