CD33 Sialic-acid-binding immunoglobulin-like lectin (Siglec) that plays a role in mediating cell-cell interactions and in maintaining immune cells in a resting state. Preferentially recognizes and binds alpha-2,3- and more avidly alpha-2,6-linked sialic acid-bearing glycans. Upon engagement of ligands such as C1q or syalylated glycoproteins, two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) located in CD33 cytoplasmic tail are phosphorylated by Src-like kinases such as LCK. These phosphorylations provide docking sites for the recruitment and activation of protein-tyrosine phosphatases PTPN6/SHP-1 and PTPN11/SHP-2. In turn, these phosphatases regulate downstream pathways through dephosphorylation of signaling molecules. One of the repressive effect of CD33 on monocyte activation requires phosphoinositide 3-kinase/PI3K. Belongs to the immunoglobulin superfamily. SIGLEC (sialic acid binding Ig-like lectin) family. Monocytic/myeloid lineage cells. In the brain, CD33 is mainly expressed on microglial cells. 3 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Cell adhesion; Membrane protein, integral
Chromosomal Location of Human Ortholog: 7 B3|7 28.25 cM
Cellular Component:  external side of plasma membrane; integral component of membrane; membrane; plasma membrane
Molecular Function:  carbohydrate binding
Biological Process:  cell adhesion
Reference #:  Q63994 (UniProtKB)
Alt. Names/Synonyms: Cd33; CD33 antigen; gp6; gp67; Myeloid cell surface antigen CD33; Sialic acid-binding Ig-like lectin 3; Sigle; Siglec-3; Siglec3
Gene Symbols: Cd33
Molecular weight: 44,824 Da
Basal Isoelectric point: 9.12  Predict pI for various phosphorylation states
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CD33

Protein Structure Not Found.


Cross-references to other databases:  STRING  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  Ensembl Gene