Recombinant Mouse MAGP-2/MFAP5 Protein, CF

MAGP-2 (Microfibril-associated glycoprotein 2), also called MFAP5 (microfibrillar associated protein 5) is a secreted, cell-associated 25 kDa mammalian member of the MFAP family of proteins (1). Mouse MAGP-2 cDNA encodes 164 amino acids (aa) including a 28 aa signal sequence, an RDG motif (aa 30 ‑ 32; absent in MAGP-1) and a central cysteine‑rich binding domain (aa 76 ‑ 133) (1 ‑ 3). Mature mouse MAGP-2 shares 86%, 96%, 84%, 85% and 85% aa identity with human, rat, bovine, porcine and canine MAGP-2, respectively. Both MAGP-1 and MAGP-2 bind and covalently crosslink Fibrillin-1 and -2 through the Cys-rich binding domain. MAGP-2, however, has a more limited distribution and binds a more limited set of extracellular matrix proteins (1 ‑ 3). This may suggest a specialized role in microfibril biology. Functionally, the MAGP-2 RGD motif binds to the integrin alphav beta3, allowing cell attachment to microfibrils (4). MAGP‑2 is thought to facilitate microfibril assembly and induce elastin fiber formation (1 ‑ 3, 5). Through its binding to EGF repeats, MAGP‑2 mediates the metalloproteinase-dependent release of Jagged1, and the metalloproteinase-independent release of Notch extracellular domains (6, 7). In endothelial cells, MAGP-2 promotes angiogenic sprouting by inhibiting Notch signaling, by binding to integrin  alphav beta3 (which then enhances VEGF signaling), and/or enhancing the endothelial cell response to FGF basic and EGF (8, 9). In ovarian cancer, MAGP-2 expression is associated with cancer cell survival, increased microvessel density, and poor prognosis (10). Skin MAGP-2 expression is increased in human scleroderma and the tight skin (TSK) mouse and may contribute to abnormal collagen accumulation in these conditions by increasing the half-life of type I collagen (11, 12). Mutations within the MAGP-2-binding region of human Fibrillin-1 can be found in Marfan syndrome (5).