Sialoadhesin (UniProt Q9BZZ2; also known as CD169, Sialic acid-binding Ig-like lectin 1, Sialic acid-binding immunoglobulin-like lectin 1, Siglec-1) is encoded by the SIGLEC1 (also known as SN) gene (Gene ID 6614) in human. Sialoadhesin/CD169/Siglec-1 is the founding member of the sialic acid-binding immunoglobulin lectins (Siglec) expressed on a variety of leukocytes and stromal cells. Sialoadhesin is initially produced with a signal sequence (a.a. 1-19), the removal of which yields the mature protein with a large extracellular portion (a.a. 20-1641), followed by a transmembrane segment (a.a. 1642-1662), and a short cytoplasmic tail (a.a. 1663-1709) with no known signal transduction or endocytosis motifs. The extracellular portion contains an N-terminal Ig-like V-type domain (a.a. 20-136), followed by sixteen Ig-like C2-type domains. Sialoadhesin is highly expressed on the subcapsular sinus (SCS) and medullary macrophages in lymph node (LN) and on marginal metallophilic macrophages in the marginal zone (MZ) of spleen. Although sialic acids are found on the surface of all cells and most secreted proteins, Only heavily sialylated, multimeric structures are captured by Sialoadhesin on macrophages via its N-terminal Ig-like V-type domain due to a low (millimolar) affinity toward sialylic acid. Sialoadhesin-mediated sialic-acid recognition allows macrophages to engage sialylated pathogens and stimulate inflammatory responses. Sialoadhesin is also reported to capture of B cell-derived exosomes via their surface-expressed α2, 3-linked sialic acids. In the lymph node, exosomes are not retained in the subcapsular sinus of Siglec1-knockout mice and penetrate deeper into the paracortex, causing an enhanced response to antigen-pulsed exosomes among Siglec1-/- mice.
Synonyms: Sialoadhesin, Sialic acid-binding Ig-like lectin 1, Siglec-1, CD169, Siglec-1 (CD169)
Application: Research Sub CategoryECM Proteins
Other Notes: Concentration: Please refer to lot specific datasheet.