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FLASH GENE

Symbol

CD22

contributors: mct/pgu - updated : 14-02-2011

HGNC name	CD22 molecule
HGNC id	1643

FLASH GENE DNA RNA EXPRESSION PROTEIN DISORDER ANIMAL & CELL MODELS

PROTEIN

PHYSICAL PROPERTIES

STRUCTURE

motifs/domains	seven Ig-like extracellular domains (exons 3–9 each encode a single Ig domain)
	a transmembrane domain encoded by exon 10
	a PTPN6-binding domain at the region containing Tyr(843) and Tyr(863)
	a long cytoplasmic tail with two immunoreceptor tyrosine based inhibitory motifs (ITIM), encoded by exons 11–14, constituting a novel conditional PTPN6-binding site of CD22 that is activated upon BCR ligation by antigen but not by anti-Ig Antibody

conjugated

GlycoP

HOMOLOGY

Homologene

FAMILY	immunoglobulin superfamily
	SIGLEC (sialic acid binding Ig-like lectin) family

CATEGORY

antigen , receptor

SUBCELLULAR LOCALIZATION	plasma membrane
	intracellular
	intracellular,cytoplasm,organelle,mitochondria
	intracellular,cytoplasm,organelle,membrane
	intracellular,cytoplasm,organelle,endoplasmic reticulum ,rough,smooth

basic FUNCTION	involved in the regulation of B cell activation sialoadhesin
	attenuates calcium signaling by potentiating plasma membrane calcium-ATPase activity
	regulator of B-cell signaling, exhibiting hallmarks of clathrin-mediated endocytosis and traffics to recycling compartments, consistent with previous reports demonstrating its localization to clathrin domains
	regulates time course of both B cell division and antibody response
	B lymphocyte specific response regulator, which is down-regulated after B-cell activation
	inhibitory coreceptor of B-cells and B-cell precursors that acts as a negative regulator of multiple signal transduction pathways critical for B-cell homeostasis, survival, activation, and differentiation
	with SIGLEC10 have partly compensatory functions and together are crucial in maintaining the B cell tolerance
	CD22 and TNFSF13B promote the survival of overlapping B-cell subsets but contribute to their maintenance through independent and complementary signaling pathways

CELLULAR PROCESS

PHYSIOLOGICAL PROCESS

PATHWAY

metabolism

signaling

a component

INTERACTION

DNA

RNA

small molecule

protein

interaction with SH2D1A (leads to constitutive CD22 tyrosine phosphorylation and decreased Ca(2+) response in B cells)

cell & other

REGULATION

ASSOCIATED DISORDERS

corresponding disease(s)

Other morbid association(s)

Type Gene Modification Chromosome rearrangement Protein expression Protein Function constitutional   deletion     splicing defect that causes the deletion of exon 12 (CD22&916;E12) results in a truncating frameshift mutation, with B-precursor leukemia

Susceptibility

potential susceptibility gene for autoimmune diseases

Variant & Polymorphism

Candidate gene	Aberrant CD22 expression is a useful marker for detection of monoclonal B cells admixed with numerous benign polyclonal B cells
Marker
Therapy target
	System Type Disorder Pubmed cancer hemopathy   antisense oligonucletides can be designed as an innovative strategy with therapeutic intent in B-precursor leukemia to shift the CD22 splicing pattern by preventing exclusion of exon 12 in the CD22 mRNA by targeting and sterically blocking the splice site

ANIMAL & CELL MODELS