Human Roof plate-specific Spondin 2 isoform 1 (R-Spondin 2, RSPO-2), 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 known human R-Spondins regulate -catenin signaling and overlap in expression and function (1-3). Like other R-Spondins, R-Spondin 2 contains two adjacent cysteine-rich furin-like domains (aa 90-134) followed by a thrombospondin (TSP-1) motif (aa 144-204) and a C-terminal region rich in basic residues (aa 207-243). The basic region appears to mediate cell surface retention but not to influence function (1). R-Spondin 2 contains one potential N-glycosylation site. Of the three reported splice isoforms of human R-Spondin 2, isoform 2 lacks residues 1-67 of isoform 1, while isoform 3 has a glycine substitution for residues 32-95 of isoform 1. Human R-Spondin 2 is expressed in organs of endodermal origin in adults, including intestine and lung, and is downregulated in tumors of these tissues (1). In the embryonic mouse, R-Spondin 2 is expressed most highly in the hippocampus and in developing teeth and bones (4). Studies in Xenopus and mouse embryos indicate that R-Spondin 2 is an extracellular activator of Wnt/ -catenin signaling and is required for myogenesis (1). Mouse R-Spondin proteins bind both LRP-6 and Frizzled-8 but do not appear to form a ternary complex. (3) R-Spondin 2 overexpression in Xenopus also blocks signaling of TGF- ligands activin, nodal and BMP-4 (1). Human R-Spondin 2 is highly conserved across species, sharing 97-98% aa identity with mouse, rat, dog, cow and opossum R-Spondin 2 and 86% aa identity with Xenopus R-Spondin 2 within aa 22-205. Mature R-Spondin 2 shares ~40% aa identity with R-Spondin 1, R-Spondin 3 and R-Spondin 4.
Source:Human R-Spondin 2 (Gln22-Gly205; Accession #NP_848660) fused to a six-histidine tag at the C-terminus; expressed in mouse NSO myeloma cell line.
Actiity:Measured by its ability to synergize rmWnt-3A induced activation of Beta-catenin response in Topflash Luciferase assay (HEK293T cells). The typical ED50 is 3-12ng/ml in the presence of 5ng/ml rmWnt-3a.
Applications:Suitable for use in ELISA and Western Blot. Other applications not tested.
Recommended Dilution:ELISA: with an apparent KD ≤150 nM. Western Blot: 22.0kD migrates as an ~ 25-29kD protein in SDS-PAGE under reducing conditions. Optimal dilutions to be determined by the researcher.
Storage and Stability:Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile PBS,0.1% BSA or HSA. Aliquot and store at -20°C. Reconstituted product is stable for 6 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.
仕様
Size：25ug
Source Antigen：Recombinant, NSO myeloma
Grade：Highly Purified
Purity：~ 90%, as determined by SDS-PAGE under reducing conditions and visualized by silver stain. Endotoxin: ≤ 1EU.
Form：Supplied as a lyophilized powder in PBS containing 50ug BSA/ug of protein. Reconstitute with 125ul sterile PBS, 0.1% HSA or BSA.
