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: 19q13.41 |
Cellular Component:
external side of plasma membrane; Golgi apparatus; nucleoplasm; peroxisome; plasma membrane; specific granule membrane; tertiary granule membrane
|
Molecular Function:
carbohydrate binding; protein binding; protein phosphatase binding; sialic acid binding; signaling receptor activity
|
Biological Process:
cell adhesion; cell-cell adhesion; cell-cell signaling; immune response-inhibiting signal transduction; negative regulation of calcium ion transport; negative regulation of cell population proliferation; negative regulation of interleukin-1 beta production; negative regulation of interleukin-8 production; negative regulation of monocyte activation; negative regulation of tumor necrosis factor production; positive regulation of protein secretion; positive regulation of protein tyrosine phosphatase activity; signal transduction
|
Reference #:
P20138
(UniProtKB)
|
Alt. Names/Synonyms: CD33; CD33 antigen (gp67); CD33 molecule; CD33 molecule transcript; FLJ00391; gp67; Myeloid cell surface antigen CD33; p67; sialic acid binding Ig-like lectin 3; Sialic acid-binding Ig-like lectin 3; Siglec-3; SIGLEC3
|
Gene Symbols: CD33
|
Molecular weight:
39,825 Da
|
Basal Isoelectric point:
8.68
Predict pI for various phosphorylation states
|
Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology®
|