|Lefty-2 in D3 Mouse Stem Cell Line. Lefty-2 was detected in immersion fixed D3 mouse embryonic stem cell line cultured with (upper panel) or without (lower panel) Recombinant Human/Mouse/Rat Activin A (Catalog # 338-AC) using Rat Anti-Mouse Lefty-2 Monoclonal Antibody (Catalog # MAB7648) at 10 µg/mL for 3 hours at room temperature. Cells were stained using the NorthernLights™ 557-conjugated Anti-Rat IgG Secondary Antibody (red; Catalog # NL013) and counterstained with DAPI (blue). Specific staining was localized to the perinuclear region. View our protocol for Fluorescent ICC Staining of Cells on Coverslips.|
Lefty-2 (Left-right determination factor 2; also Lefty-B [in human]) is a atypical member of the TGF-beta family of proteins. It is expressed during early embryogenesis in both the primitive streak and left-side lateral plate mesoderm. In the adult, Lefty-2 appears in oviduct epithelium. Lefty-2 acts in a manner reminiscent of that for Chordin and Noggin, and it is assumed that Lefty-2 is an antagonist of BMP activity. Notably, Lefty-2 and Nodal are likely under the control of Lefty-1, and thus all three molecules would appear to contribute to the creation of a left side-type body plan. Mouse Lefty-2 is synthesized as a 368 amino acid (aa) preproprecursor. It contains a 21 aa signal sequence, plus a 347 aa, 41-42 kDa bioactive proprecursor that may undergo proteolytic processing at one of two downstream cleavage sites. If cleavage occurs after Arg77, the resulting 33-34 kDa mature form (aa 78-368) is biologically inactive; if cleavage occurs after Arg135, the resulting 27-28 kDa mature form (aa 136-368) is biologically active. Lefty-2 is not a covalent homodimer and has been suggested to act as a monomer. Over aa 78-368, mouse Lefty-2 shares 94%, 83% and 95% aa sequence identity with rat Lefty-2, human Lefty-B and mouse Lefty-1, respectively.