Biological Activity
In mammalian epithelia, COMMD9 (copper metabolism domain containing 9) causes a suppression in the expression of epithelial sodium channel (ENaC) and also results in reduced amiloride-sensitive current. This protein might thus be responsible for regulating the cell surface expression of ENaC, thereby controlling Na+ transport. The function of this protein is not yet very clear, but it interacts with NF-KB and suppresses NF-KB-mediated transcription. This protein interacts with Notch receptor family proteins and CCC subunits, and in cells lacking COMMD9 protein, Notch family receptors are retained in endosomes and eventually degraded by lysosomes. Inactivation of this gene in mouse leads to embryo fatality and complex cardiovascular changes.
