FRAS1 Related Extracellular Matrix Protein 1 (FREM1)

The mouse and human FREM1 proteins contain an N-terminal signal peptide, 12 chondroitin sulfate proteoglycan (CSPG) repeats, a calcium-binding loop similar to those of sodium-calcium exchangers , and a C-terminal C-type lectin domain. FREM1 also has sites for N- and O-glycosylation. FREM1 shares significant similarity with FRAS1, particularly through the CSPG repeats, but FREM1 lacks additional domains found in FRAS1. In situ hybridization and immunohistochemical analysis detected wide Frem1 expression during mouse embryonic development in the dermis and in a number of differentiating epidermal structures, such as mammary and meibomian glands, teeth, and hair follicles. Expression appeared in regions of epithelial-mesenchymal interaction and epidermal remodeling.