MAM Domain Containing Glycosylphosphatidylinositol Anchor 1 (MDGA1)

MDGA1 exhibits the structure of a glycosylphosphatidylinositol (GPI) membrane-anchored protein with an ectodomain containing an N-terminal signal peptide followed by 6 immunoglobulin domains, a single fibronectin type III domain, a MAM domain, and a C-terminal signal containing a potential cleavage site for GPI anchoring to the cell membrane. Northern blot analysis of multiple normal human tissues and cancer cell lines detected an approximately 9.5-kb brain-specific band and an approximately 5.0-kb band in heart, skeletal muscle, and kidney, and in most human cancer cell lines studied, with higher expression in melanoma, lymphoblastic leukemia, Burkitt lymphoma, and lung cancer. MDGA1 was frequently expressed at a higher level in tumors than in corresponding normal tissues, including colon, lung, uterus, stomach, and breast, indicating a role in tumor progression.