Mouse RGM-C Alexa Fluor™ Plus 680‑conjugated Antibody

RGM-C, also known as hemojuvelin, is a member of the repulsive guidance molecule (RGM) family of GPI-linked neuronal and muscle membrane glycoproteins (1). RGM‑C is expressed in striated muscle and periportal hepatocytes (2-4). The protein undergoes partial cleavage intracellularly, resulting in a disulfide-linked dimer of the 14 kDa N-terminal and 33 kDa C-terminal portions (3, 5, 6). The N-terminal fragment contains an RGD motif, while the C-terminal fragment carries the GPI attachment site (3, 6). An alternatively spliced isoform lacks the N-terminal fragment. Full length RGM-C can also be released from the cell and circulates in the blood (5, 7). RGM-C is disrupted in type 2A juvenile hemochromatosis, a hereditary iron homeostasis disorder characterized by excessive iron accumulation (4). Loss of RGM-C function results in decreased expression of the iron regulatory hormone hepicidin and increased iron deposition in liver, pancreas, and heart (4, 8). Membrane associated RGM-C upregulates hepicidin while soluble RGM-C downregulates hepicidin expression (7). This appears to be an iron-responsive regulatory system, as high blood iron levels reduce the amount of soluble RGM-C produced (7). RGM-C, similar to RGM-A, associates with neogenin (6). Disease-related point mutations can prevent internal RGM-C cleavage or its ability to interact with neogenin (5, 6). Experimental inflammatory conditions result in decreased RGM-C expression and increased hepicidin expression, although the two effects occur independently (4, 9). RGM-C also functions as a BMP co-receptor and enhances BMP-2 and BMP-4 signaling (10). In this context, RGM-C enhances the BMP-2 upregulation of hepatic hepicidin (10). Mature mouse RGM-C shares 89% and 97% amino acid (aa) sequence identity with human and rat RGM-C, respectively. It shares 51% and 44% aa sequence identity with mouse RGM-A and RGM-B, respectively.