Collectrin, Fc Chimera, Recombinant, Human, aa15-141 (NX17, TMEM27)

Collectrin, also known as TMEM27 and NX-17, is a 35-45kD transmembrane protein that shows structural similarity to the C-terminal region of Angiotensin Converting Enzyme 2 (ACE-2) but lacks peptidase activity (1, 2). Mature human Collectrin consists of a 127 amino acid (aa) extracellular domain (ECD), a 21 aa transmembrane segment, and a 60aa cytoplasmic domain (3). Within the ECD, human Collectrin shares 87% and 89% aa sequence identity with mouse and rat Collectrin, respectively. Collectrin is expressed as a disulfide-linked homodimer of variably glycosylated subunits (4-6). It is highly expressed in the proximal convoluted tubules of renal collecting ducts and inhibits the proliferation of tubule epithelial cells (3, 6-8). It associates with several amino acid transporters on the luminal surface of these cells, where it is required for the reabsorption of multiple amino acids (7-9). Collectrin is also expressed in pancreatic islet beta cells and enhances glucose-stimulated insulin secretion as well as insulin resistance (4, 5, 9, 10). In both the kidney and pancreas, cytoplasmic Collectrin interacts with multiple components of the SNARE complex and other vesicle trafficking proteins (5, 6). A 25kD glycosylated fragment of the ECD can be shed from both renal tubule cells and pancreatic beta cells (4, 10). In beta cells, shedding is mediated by BACE2, and the portion left in the membrane can be subsequently cleaved by gamma-Secretase, releasing the intracellular domain into the cytosol (11). Inhibition of Collectrin shedding from beta cells results in increased beta cell mass and insulin secretion (11). Source: Recombinant protein corresponding to aa15-141 from human Collectrin Fc Chimera, CHO-derived. Molecular Weight: ~54-64kD, Endotoxin: <0.10EU/1ug (LAL method). Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.