Recombinant Human Myeloid cell surface antigen CD33 (CD33), Truncated

Uniprot Id

P20138

Target Species

Human

Target Name

CD33

Target Full Name

Myeloid cell surface antigen CD33

Target Function

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.

Target Subcellular Location

[Isoform CD33M]: Cell membrane; Single-pass type I membrane protein.; [Isoform CD33m]: Peroxisome.

Target Protein Families

Immunoglobulin superfamily, SIGLEC (sialic acid binding Ig-like lectin) family

Target Tissue Specificity

Monocytic/myeloid lineage cells. In the brain, CD33 is mainly expressed on microglial cells.

Target Research Area

Immunology

Target Synonyms

CD33; SIGLEC3; Myeloid cell surface antigen CD33; Sialic acid-binding Ig-like lectin 3; Siglec-3; gp67; CD antigen CD33

Target Background

Enables protein phosphatase binding activity and sialic acid binding activity. Involved in several processes, including negative regulation of cytokine production; negative regulation of monocyte activation; and positive regulation of protein tyrosine phosphatase activity. Located in several cellular components, including Golgi apparatus; external side of plasma membrane; and peroxisome.