FRAS1 Related Extracellular Matrix Protein 3 (FREM3)

By searching databases for sequences similar to mouse Frem1, Smyth et al. (2004) identified mouse and human FREM3. The deduced proteins contain an N-terminal signal peptide, 12 chondroitin sulfate proteoglycan (CSPG) repeats, and 3 calcium-binding loops similar to those of sodium-calcium exchangers. They also have sites for N-glycosylation. FREM3 shares significant similarity with FRAS1.The International Radiation Hybrid Mapping Consortium mapped the FREM3 gene to chromosome 4.Frem1-knockout mice had reduced localization of Fras1 and Frem2 to the epidermal basement membrane. Similarly, Frem2-mutant """myelencephalic blebs""" (my) mice showed depletion of Frem2, as well as Fras1 and Frem1, at the basement membrane.