Human RGM-A Biotinylated Antibody

Human Repulsive Guidance molecule (RGM) is a 33 kDa GPI-linked member of an expanding RGM-related family of neuronal and muscle-expressed membrane proteins (1). It is synthesized as a 450 amino acid (aa) preproprotein that contains a 47 aa signal sequence, a 121 aa N-terminal prosegment, a 256 mature region and a 26 aa C-terminal prosegment (2). The N-terminal prosegment contains an RGD tripeptide and the molecule’s only two potential N-linked glycosylation sites. The mature segment shows an abbreviated von Willebrand factor domain. Proteolytic processing occurs at an aspartic acid-proline bond, creating a predicted 32 kDa mature region (2). The mature region of human RGM-A has 88% and 93% aa identity to the chick and mouse mature region of RGM-A, respectively. When compared to human RGMb and c, the mature region of human RGM-A shows 58% and 54% aa identity, respectively. Recombinant chick RGM-A has been reported to induce collapse of temporal but not nasal growth cones, and to repel temporal retinal axons in vitro. This suggests a role in the development of the retina-superior colliculus connection. In mammals, however, this activity is not so evident, and thus its function in this system is uncertain (3). Alternatively, in mice, RGM-A is said to be needed for neural tube closure, and may play a role in entorhinal-hippocampal connections (3, 4). The receptor for RGM-A is reported to be neogenin (5, 6). RGM-A has also been shown to be a bone morphogenic protein co-receptor, able to bind both BMP-2 and BMP-4 (7).