Human MDGA1 Alexa Fluor™ Plus 680‑conjugated Antibody

MDGA1 (MAM domain containing glycosylphosphatidylinositol anchor 1; also named GPIM) is a 140 kDa member of the Ig superfamily of proteins (1). Human MDGA1 is synthesized as a 955 amino acid (aa) precursor that contains an 18 aa signal sequence, a 914 aa mature chain, and a 23 aa propeptide. The mature chain consists of six Ig-like domains, a fibronectin type III domain (aa 640‑739), a MAM domain (aa 751‑918), 11 potential sites for N-linked glycosylation, and a GPI anchor (aa 932) (1‑3). Alternative splicing in human MDGA1 produces an isoform variant that shows a 48 aa substitution for aa corresponding to positions 926‑955. Mature human MDGA1 shares 96%, 94%, and 80% aa sequence identity with mature rat, mouse, and chick MDGA1, respectively. MDGA1 is structurally similar to other IgCAMS, such as the L1 family and axonin 1, which have roles in cell adhesion, migration, and process outgrowth (4). Expression analysis in normal human tissues reveals that MDGA1 is expressed as a 5 kb and 9.5 kb mRNA (2). The smaller transcript is highly expressed in some human cancer cell lines, as well as in different primary tumors (lung, colon, uterus, stomach, and breast) (2). Gene expression is higher in several tumor tissues as compared with corresponding normal tissues, and may be involved in tumor progression (2). The 9.5 kb transcript is found exclusively in the central and peripheral nervous system (1‑2, 4). One study shows that MGDA1 is expressed in mice neocortex by layer 2/3 neurons throughout their development (4), and it is involved in controlling the migration and lamination of layer 2/3 neurons (5).