Interacts with NEDD4 (By similarity). Interacts (via cytoplasmic domain) with transcriptional coactivator YAP1 (PubMed:17502622). Widely expressed with highest levels in kidney (PubMed:23873930). Also highly expressed in the thyroid (PubMed:9256434, PubMed:23873930). Gamma-carboxyglutamate residues are formed by vitamin K dependent carboxylation. These residues are essential for the binding of calcium.