CD22_HUMAN » B-cell receptor CD22

CD22_HUMAN » B-cell receptor CD22
Magnify CD22_HUMAN » B-cell receptor CD22Enlarged view of image
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Topology in Plasma membrane
Topologyextracellular side
cytoplasmic side
CD22_HUMAN » B-cell receptor CD22 » B-lymphocyte cell adhesion molecule;BL-CAM; Sialic acid-binding Ig-like lectin 2;Siglec-2; T-cell surface antigen Leu-14;
Hydrophobic Thickness 33.2 ± 2.4 Å
Tilt Angle 2 ± 2°
ΔGtransfer -16.6 kcal/mol
ΔGfold -14.0 kcal/mol
Links UniProtKB, Pfam, Interpro, iHOP, STRING, HGNC
Topology Out
TM Segments 687-708 (681-710)
Pathways

B cell receptor signaling pathway (KEGG)

Cell adhesion molecules (KEGG)

Hematopoietic cell lineage (KEGG)

PDB none
OPM none
Complexes none
Interactions

CD19, Complex: CD19:CD22, PubMed

IGHM, Complex: CD22:IGHM, PubMed

PTPRC, Complex: PTPRC:CD22, PubMed

SIAT1, Complex: CD22:SIAT1, PubMed

Domains

AA: 143-229, PDBID: 4OF8, Subunit B, Seq Identity:25%, CD80-like C2-set immunoglobulin domain

AA: 242-313, PDBID: 3K0W, Subunit A, Seq Identity:37%, Immunoglobulin domain

AA: 331-400, PDBID: 3ALP, Subunit A, Seq Identity:35%, Immunoglobulin domain

AA: 510-589, PDBID: 1E4J, Subunit A, Seq Identity:31%, Immunoglobulin domain

AA: 597-663, PDBID: 1F2Q, Subunit A, Seq Identity:36%, Immunoglobulin domain

UniProt annotation for CD22_HUMAN » B-cell receptor CD22
FUNCTION: Mediates B-cell B-cell interactions. May be involved in the localization of B-cells in lymphoid tissues. Binds sialylated glycoproteins; one of which is CD45. Preferentially binds to alpha-2,6-linked sialic acid. The sialic acid recognition site can be masked by cis interactions with sialic acids on the same cell surface. Upon ligand induced tyrosine phosphorylation in the immune response seems to be involved in regulation of B-cell antigen receptor signaling. Plays a role in positive regulation through interaction with Src family tyrosine kinases and may also act as an inhibitory receptor by recruiting cytoplasmic phosphatases via their SH2 domains that block signal transduction through dephosphorylation of signaling molecules.

SUBUNIT: Predominantly monomer of isoform CD22-beta. Also found as heterodimer of isoform CD22-beta and a shorter isoform. Interacts with PTPN6/SHP-1, LYN, SYK, PIK3R1/PIK3R2 and PLCG1 upon phosphorylation. Interacts with GRB2, INPP5D and SHC1 upon phosphorylation (By similarity). May form a complex with INPP5D/SHIP, GRB2 and SHC1.

TISSUE SPECIFICITY: B-lymphocytes.

DOMAIN: Contains 4 copies of a cytoplasmic motif that is referred to as the immunoreceptor tyrosine-based inhibitor motif (ITIM). This motif is involved in modulation of cellular responses. The phosphorylated ITIM motif can bind the SH2 domain of several SH2- containing phosphatases.

UniProt features for CD22_HUMAN » B-cell receptor CD22
SIGNAL 1 19 Potential.
CHAIN 20 847 B-cell receptor CD22.
DOMAIN 20 138 Ig-like V-type.
DOMAIN 143 235 Ig-like C2-type 1.
DOMAIN 242 326 Ig-like C2-type 2.
DOMAIN 331 416 Ig-like C2-type 3.
DOMAIN 419 500 Ig-like C2-type 4.
DOMAIN 505 582 Ig-like C2-type 5.
DOMAIN 593 676 Ig-like C2-type 6.
MOTIF 760 765 ITIM motif 1.
MOTIF 794 799 ITIM motif 2.
MOTIF 820 825 ITIM motif 3.
MOTIF 840 845 ITIM motif 4.
DISULFID 39 167 By similarity.
DISULFID 44 102 By similarity.
DISULFID 161 219 By similarity.
DISULFID 265 309 By similarity.
DISULFID 353 396 By similarity.
DISULFID 442 484 By similarity.
DISULFID 529 571 By similarity.
DISULFID 616 659 By similarity.
Amino Acid Sequence for CD22_HUMAN » B-cell receptor CD22
MHLLGPWLLL LVLEYLAFSD SSKWVFEHPE TLYAWEGACV WIPCTYRALD GDLESFILFH NPEYNKNTSK FDGTRLYEST KDGKVPSEQK RVQFLGDKNK NCTLSIHPVH LNDSGQLGLR MESKTEKWME RIHLNVSERP FPPHIQLPPE IQESQEVTLT CLLNFSCYGY PIQLQWLLEG VPMRQAAVTS TSLTIKSVFT RSELKFSPQW SHHGKIVTCQ LQDADGKFLS NDTVQLNVKH TPKLEIKVTP SDAIVREGDS VTMTCEVSSS NPEYTTVSWL KDGTSLKKQN TFTLNLREVT KDQSGKYCCQ VSNDVGPGRS EEVFLQVQYA PEPSTVQILH SPAVEGSQVE FLCMSLANPL PTNYTWYHNG KEMQGRTEEK VHIPKILPWH AGTYSCVAEN ILGTGQRGPG AELDVQYPPK KVTTVIQNPM PIREGDTVTL SCNYNSSNPS VTRYEWKPHG AWEEPSLGVL KIQNVGWDNT TIACAACNSW CSWASPVALN VQYAPRDVRV RKIKPLSEIH SGNSVSLQCD FSSSHPKEVQ FFWEKNGRLL GKESQLNFDS ISPEDAGSYS CWVNNSIGQT ASKAWTLEVL YAPRRLRVSM SPGDQVMEGK SATLTCESDA NPPVSHYTWF DWNNQSLPYH SQKLRLEPVK VQHSGAYWCQ GTNSVGKGRS PLSTLTVYYS PETIGRRVAV GLGSCLAILI LAICGLKLQR RWKRTQSQQG LQENSSGQSF FVRNKKVRRA PLSEGPHSLG CYNPMMEDGI SYTTLRFPEM NIPRTGDAES SEMQRPPPDC DDTVTYSALH KRQVGDYENV IPDFPEDEGI HYSELIQFGV GERPQAQENV DYVILKH