Description
Siglecs, short for sialic acid binding Ig-like lectins are cell surface receptors and members of the immunoglobulin superfamily (IgSF) that recognize sialic acids. Their ability to recognize sialic acids using an immunoglobulin domain places them in the group of I-type (Ig-type) lectins. They are transmembrane proteins that contain an N-terminal V-like immunoglobulin (IgV) domain that binds sialic acid and a variable number of C2-type Ig (IgC2) domains. The subsequent cloning of sialoadhesin by Crocker revealed homology to CD22 (Siglec-2), CD33 (Siglec-3) and myelin-associated glycoprotein (MAG/Siglec-4), leading to a proposal for a family of "sialoadhesins". Varki then suggested the term Siglec as better alternative, and as a subset of I-type (Ig-type) lectins