RSPO-2, Recombinant, Mouse (Rspo2, R-spondin-2, Cysteine-rich and Single Thrombospondin Domain-conta

Roof plate-specific Spondin 2 isoform 1 (R-Spondin 2, RSPO2), also known as cysteine-rich and single thrombospondin domain containing protein 2 (Cristin 2), is a 33kD secreted protein that belongs to the R-Spondin family. The four R-Spondins regulate Wnt/B-catenin signaling and overlap in expression and function. Like other R-Spondins, RSPO2 contains two adjacent cysteine-rich furin-like domains aa90-134 followed by a thrombospondin (TSP-1) motif aa144-204 and a C-terminal region rich in basic residues aa207-243. The basic region binds heparin and mediates cell surface retention and extracellular matrix attachment while the furin-like domains are required for Wnt/B-catenin signaling. RSPO2 contains one potential N-glycosylation site. Mature mouse RSPO2 shares 97-98% aa identity with human, rat, equine, canine and bovine RSPO2 and ~40% aa identity with RSPO1, RSPO3 and RSPO4. One potential 237aa mouse isoform diverges after aa206 and lacks a basic region. Human RSPO2 is expressed in organs of endodermal origin in adults, including intestine and lung, and is down-regulated in tumors of these tissues. In the embryonic mouse, RSPO2 expression is concentrated in the apical epidermal ridge, hippocampus, and developing muscle, teeth and bones. Deletion of RSPO2 results in down-regulation of Wnt activity in these areas, malformations of the facial skeleton and limbs, and respiratory failure at birth. RSPO2 is an extracellular potentiator of Wnt/B-catenin signaling. It functions at least in part by binding LRP-6, stimulating its long-term phosphorylation and down-regulating its internalization. RSPO proteins, especially RSPO2 and RSPO3, also antagonize DKK1 activity by interfering with DKK1-mediated LRP-6 and Kremen association. Source: Recombinant corresponding to aa1-205 from mouse R-Spondin 2 expressed in Chinese Hamster Ovary cell line, CHO. Molecular Weight: ~21kD, 20kD, Biological Activity: Measured by its ability to induce activation of B-catenin response in a Super (16X) Topflash Luciferase assay using HEK293T human embryonic kidney cells. The ED50 for this effect is typically 3-15ng/ml in the presence of 5ng/m Recombinant Mouse Wnt-3a. Endotoxin: ~1EU/1ug (LAL) , Storage and Stability:, Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile buffer. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 3 months 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.