Kremen2, Recombinant, Rat (Kringle-containing Protein Marking the Eye and the Nose, Kringle Domain-containing Transmembrane Protein 2)
Biozol Catalog Number:
USB-K5002-02
Supplier Catalog Number:
K5002-02
Alternative Catalog Number:
USB-K5002-02-25
Manufacturer:
US Biological
Category:
Molekularbiologie
Kremen (Kringle-containing protein marking the eye and the nose) proteins are type I transmembrane proteins that contain extracellular kringle, WSC and CUB domains, and an intracellular region with no conserved motifs (1). Two related molecules, Kremen-1 and -2, have been identified. Kremens bind with high affinity to a subset of the secreted Dickkopf proteins (Dkk-1, -2, and -4) to modulate the canonical Wnt signaling pathway (2). This pathway is transduced by a ternary receptor complex composed of Wnt, the seven-transmembrane domain receptor Frizzled, and the LDL-receptor-related protein 5/6 (LRP5/6) coreceptor (3, 4). Dkk-1 and -4 bind directly to the LRP5/6 coreceptor to antagonize the canonical Wnt/b-catenin signaling pathway. The planar cell polarity (PCP) signaling pathway is not affected as it does not involve LRP5/6 (2). In contrast, Dkk-3 has no effect on Wnt signaling. Dkk-2 can function either as an LRP agonist or antagonist, depending on whether or not the cell expresses Kremen (5). Kremen cooperates with Dkk to antagonize Wnt signaling via formation of a Kremen-Dkk-LRP ternary complex which is internalized and cleared from the cell surface (4). Binding requires all three extracellular domains of Kremen, and the second cysteine-rich domain of Dkk (4). The predicted rat Kremen-2 cDNA encodes a 490 aa glycosylated protein with a 51 aa signal peptide, a 340 aa extracellular domain, a 24 aa transmembrane domain, and a 75 aa cytoplasmic domain. Within the ECD, rat Kremen-2 shares 91% and 98% aa sequence identity with human and mouse Kremen-2, respectively, and 46% with rat Kremen-1. Mouse myeloma cell line, NS0-derived recombinant protein corresponding to rat Kremen-2 protein, Gly53-Arg395, with a C-terminal 6-His tag Activity: Measured by its binding ability in a functional ELISA. Immobilized rrKremen-2 at 4ug/ml can bind rhDkk-1 with an apparent KD <15nM. Storage and Stability: Lyophilized and reconstituted products are stable for 6 months after receipt at -20C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store at -20C. 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.
