siglec-6

Siglec-6 Protein, Human, Recombinant (His) is expressed in HEK293 mammalian cells with His tag. The predicted molecular weight is 35.24 kDa and the accession number is NP_942142.3.

Siglec-6 Protein, Human, Recombinant (hFc) is expressed in HEK293 mammalian cells with hFc tag. The predicted molecular weight is 60.7 kDa and the accession number is O43699-3.

Siglecs (Sialic acid binding Ig-like Lectins) are I-type (Ig-type) lectins that belong to the Ig superfamily. They are characterized by an N-terminal Ig-like V-type domain which mediates sialic acid binding, followed by varying numbers of Ig-like C2-type domains.Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Binds to alpha-2,6-linked sialic acid. The sialic acid recognition site may be masked by cis interactions with sialic acids on the same cell surface.

Siglecs are sialic acid specific I‑type lectins that are characterized by an extracellular domain (ECD) with an N‑terminal Ig‑like V‑set domain followed by varying numbers of Ig‑like C2‑set domains. Mouse Siglec‑E, also known as Myeloid Inhibitory Siglec (MIS), is an 80 ‑ 85 kDa member of the CD33‑related subfamily of Siglecs. Rodent and primate Siglec gene families have significantly diverged, and Siglec‑9 is the most likely human ortholog of mouse Siglec‑E. Siglec‑E is expressed as a heavily N‑glycosylated disulfide‑linked homodimer and shows binding preference for disialic acids in the alpha 2‑8 linkage. Siglec‑E is up‑regulated and additionally phosphorylated following cellular stimulation by a variety of TLR agonists. Siglec‑E signaling negatively regulates the LPS‑induced production of TNF‑ alpha and IL‑6 by macrophages. Its up‑regulation in macrophages parallels the development of endotoxin tolerance. Siglec‑E recognition of sialylated determinants on virulent T. cruzi contributes to the suppression of dendritic cell IL‑12 p40 production.

Siglec-8 is also known as SIGLEC8, SAF2, SIGLEC-8, SIGLEC8L and sialic acid binding Ig like lectin 8, is an approximately 75 kDa transmembrane glycoprotein in the Siglec family of sialic acid-binding immune regulatory molecules. Siglec-8 is expressed on eosinophils, basophils, and mast cells, and it shows a binding preference for the carbohydrate 6-O sulfated sLex. At the tissue level, Siglec-8 mRNA was found to be most highly expressed in lung, PBMCs, spleen, and kidney. Mature human Siglec-8 consists of a 347 amino acid (aa) extracellular domain (ECD) with three Ig-like domains, a 21 aa transmembrane segment, and a 115 aa cytoplasmic domain with two tyrosine based signaling motifs. Alternative splicing generates additional isoforms that either lack most of the second Ig-like domain or have a substituted cytoplasmic domain without the signaling motifs. Cross-linking of Siglec-8 inhibits Fc epsilon RI alpha induced mast cell degranulation. It also induces eosinophil apoptosis, an effect which is enhanced by the eosinophil-activating cytokines IL-5, IL-33, and GM-CSF.