Siglec-3/CD33 Products

Description

Sialic acid-binding Ig-like lectin 3 (Siglec-3), also known myeloid cell surface antigen CD33 (CD33), is a I-type (Ig-type) lectin belonging to the sialoadhesin subclass of the immunoglobulin superfamily (1). Siglecs 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 in the extracellular domain (ECD). Fourteen human and nine mouse Siglecs have been characterized and are divided into 2 families: CD33 related and evolutionarily conserved (1-3). Mature Siglec-3 consists of an ECD with one Ig-like V-type domain and one Ig-like C2 domain, a single transmembrane and a cytoplasmic tail containing two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) (3). Within the ECD, cynomolgus/rhesus Siglec-3 shares 89% amino acid sequence identity with human Siglec-3. An isoform of Siglec-3 lacking the N-terminal V-type domain, generated by alternative splicing, has been identified in humans (4). Siglec-3 is a disulfide-linked homodimer expressed on neutrophils, monocytes, macrophages and dendritic cells (2). Each Siglec family member has a distinct preference for binding the various types of sialylated glycans found on the surface of mammalian cells and they most likely evolved to regulate host immune responses via the recognition of self-glycans (5). Siglec-3 may be implicated in the regulation of both the innate but also the adaptive immunity and human Siglec-3 continues to be a therapeutic target for the treatment of acute myeloid leukemia and is a high potential risk factor for Alzheimer's (6). Siglec-3's ligands have yet to be classified, however terminal epitope preferences are conserved between Siglec-3 and Siglec-9 when binding to glycans (7). R&D Systems in-house testing indicates that Siglec-3 binds to LGALS3BP, consistent with the demonstrated functional interactions between other members of these protein families (8).

Bioinformatics

Uniprot	XP_045235686.1
Product By Gene ID	945
Alternate Names	CD33 antigen (gp67) CD33 antigen CD33 molecule CD33 FLJ00391 gp67 myeloid cell surface antigen CD33 p67 sialic acid binding Ig-like lectin 3 Sialic acid-binding Ig-like lectin 3 Siglec3 Siglec-3 SIGLEC3gp67

Related Siglec-3/CD33 Blog Posts

Check out the latest blog posts on Siglec-3/CD33.

Harnessing Natural Killer Cell Activity for Anti-Tumor Immunotherapy By Victoria Osinski, PhDWhat’s “Natural” About Natural Killer (NK) Cells?For immunologists, the term cytotoxicity often conjures up images of an army of antigen specific CD8+ T cells deploying to ...    Read more.

Read more Siglec-3/CD33 related blogs.