siglec 5

Siglec-5 Protein, Human, Recombinant (His & Avi) is expressed in HEK293 mammalian cells with C-His-Avi tag. The predicted molecular weight is 49.3 kDa and the accession number is O15389.

Group B Streptococcus (GBS) causes invasive infections in human newborns. the GBS β-protein attenuates innate immune responses by binding to sialic acid-binding immunoglobulin-like lectin 5 (Siglec-5), an inhibitory receptor on phagocytes.the polymorphism could influence the risk of prematurity among human fetuses of mothers colonized with GBS. This first functionally proven example of a paired receptor system in the Siglec family has multiple implications for regulation of host immunity.

Human Siglec-5 are Itype(Igtype) lectins belonging 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. SIGLEC5 has also been designated CD170, they are expressed by monocytic or myeloid lineage cells, and also found at high levels in peripheral blood leukocytes, spleen, bone marrow and at lower levels in lymph node, lung, appendix, placenta, pancreas and thymus. SIGLEC5 are expressed by monocytes and neutrophils but absent from leukemic cell lines representing early stages of myelomonocytic differentiation. Siglec5 to 11 share a high degree of sequence similarity with CD33 Siglec3 both in their extracellular and intracellular regions. They are collectively referred to as CD33 related Siglecs. One remarkable feature of the CD33 related Siglecs is their differential expression pattern within the hematopoietic system This fact, together with the presence of two conserved immunoreceptor tyrosinebased inhibition motifs (ITIMs) in their cytoplasma tails, suggests that CD33 related Siglecs are involved in the regulation of cellular activation within the immune system.

Siglec-5 Protein, Human, Recombinant (His & Avi), Biotinylated is expressed in HEK293 mammalian cells with C-His-Avi tag. The predicted molecular weight is 49.3 kDa and the accession number is O15389.

Sialic acid-binding Ig-like lectin 5 is a protein that in Cynomolgus is encoded by the SIGLEC5 gene, Cynomolgus SIGLEC5 cDNA encodes 551 amino acids (aa) that include a 16 aa signal sequence, a 439aa extracellular domain (ECD) with three Ig-like domains, a transmembrane region and a cytoplasma tail. No Siglec has been shown to recognized any cell surface ligand other than sialic acids, suggesting that interactions with glycans containing this carbohydrate are important in mediating the biological functions of Siglecs. Siglec5 to 11 share a high degree of sequence similarity with CD33 Siglec3 both in their extracellular and intracellular regions. Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Binds equally to alpha-2,3-linked and 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.

Siglec-5 Protein, Human, Recombinant is expressed in HEK293 mammalian cells. The predicted molecular weight is 47.2 kDa and the accession number is O15389.

Siglec-5 Protein, Human, Recombinant (hFc) is expressed in HEK293 mammalian cells with hFc tag. The predicted molecular weight is 73.4 kDa and the accession number is O15389.

CD33 is a type I Lectin belonging to the Ig superfamily. CD33 contains an N terminal Ig like V type domain, which mediates sialic acid binding, followed by one Ig like C2 type domain, a transmembrane region and a cytoplasmic tail containing two conserved immunoreceptor tyrosine based inhibition motifs (ITIMs). Eleven human Siglecs have been characterized. Siglecs 5 to 11 share a high degree of sequence similarity with CD33 Siglec3 both in their extracellular and intracellular regions. They are collectively referred to as CD33 related Siglecs. CD33 related Siglecs have differential expression pattern within the hematopoietic system. They are involved in the regulation of cellular activation within the immune system. Siglec 3 expression is restricted to cells of myelomonocytic lineage. Siglec3 recruits SHP1 and SHP2 to its ITIMs upon phosphorylation.

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.

Siglec 5 to 11 share a high degree of sequence similarity with CD33 Siglec-3 both in their extracellular and intracellular regions. They are collectively referred to as CD33-related Siglecs. One remarkable feature of the CD33-related Siglecs is their differential expression pattern within the hematopoietic system. This fact, together with the presence of two conserved immunoreceptor tyrosine-based inhibition motifs (ITIMs) in their cytoplasmic tails, suggests that CD33-related Siglecs are involved in the regulation of cellular activation within the immune system. Mouse Siglec-F cDNA encodes a 569 amino acid polypeptide with a hydrophobic signal peptide, an N-terminal Ig-like V-type domain, three Ig-like C2-type domains, a transmembrane region and a cytoplasmic tail. The expression of Siglec-F is restricted to the cells of myelomonocytic lineage. Mouse Siglec-F is likely an ortholog of human Siglec-5. Unlike many human CD33-related Siglecs, which show similar binding to both alpha 2,3- and alpha 2,6-linked sialic acids, mouse Siglec-F preferentially recognize alpha 2,3-linked sialic acid.