CD22

 CD22, or cluster of differentiation-22, is a molecule belonging to the SIGLEC family of lectins.^[5] It is found on the surface of mature B cells and to a lesser extent on some immature B cells. Generally speaking, CD22 is a regulatory molecule that prevents the overactivation of the immune system and the development of autoimmune diseases.^[6]

CD22
Identifiers
Aliases	CD22, SIGLEC-2, SIGLEC2, CD22 molecule
External IDs	OMIM: 107266 MGI: 88322 HomoloGene: 31052 GeneCards: CD22
Gene location (Human) Chr. Chromosome 19 (human)[1] Band 19q13.12 Start 35,319,261 bp[1] End 35,347,361 bp[1]
Gene location (Mouse) Chr. Chromosome 7 (mouse)[2] Band 7 B1|7 19.26 cM Start 30,865,402 bp[2] End 30,880,342 bp[2]
RNA expression pattern More reference expression data
Gene ontology Molecular function • GO:0001948 protein binding • carbohydrate binding • IgM binding • receptor binding • protein phosphatase binding • sialic acid binding • CD4 receptor binding Cellular component • integral component of membrane • cell membrane • extracellular exosome • membrane • cytoplasm • early endosome • cell surface • neuronal cell body membrane • recycling endosome Biological process • cell adhesion • regulation of endocytosis • regulation of B cell proliferation • B cell activation • regulation of immune response • negative regulation of calcium-mediated signaling • negative regulation of B cell receptor signaling pathway • negative regulation of immunoglobulin secretion Sources:Amigo / QuickGO
Orthologs
Species	Human	Mouse
Entrez	933	12483
Ensembl	ENSG00000012124	ENSMUSG00000030577
UniProt	P20273	P35329
RefSeq (mRNA)	NM_024916 NM_001185099 NM_001185100 NM_001185101 NM_001278417 NM_001771	NM_001043317 NM_009845
RefSeq (protein)	NP_001172028 NP_001172029 NP_001172030 NP_001265346 NP_001762	NP_001036782 NP_033975
Location (UCSC)	Chr 19: 35.32 – 35.35 Mb	Chr 7: 30.87 – 30.88 Mb
PubMed search	[3]	[4]
Wikidata
View/Edit Human View/Edit Mouse

CD22 is a sugar binding transmembrane protein, which specifically binds sialic acid with an immunoglobulin (Ig) domain located at its N-terminus. The presence of Ig domains makes CD22 a member of the immunoglobulin superfamily. CD22 functions as an inhibitory receptor for B cell receptor (BCR) signaling. It is also involved in the B cell trafficking to Peyer's patches in mice.^[7]

As a drug targetEdit

An immunotoxin, BL22, that targets this receptor is being tested at the NIH.^[8]

As a treatment for acute lymphoblastic leukemia (ALL), Inotuzumab ozogamicin is an antibody-drug conjugate that targets this molecule.

InteractionsEdit

CD22 has been shown to interact with Grb2,^[9][10] PTPN6,^{[10][11][12][13][14]} LYN,^[9][12] SHC1^[9] and INPP5D.^[9]

This article uses material from the Wikipedia article  Metasyntactic variable, which is released under the  Creative Commons Attribution-ShareAlike 3.0 Unported License.