CD22 or cluster of differentiation-22, is a molecule belonging to the SIGLEC family of lectins.[1] 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.[2]
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) signalling.
An immunotoxin, BL22, that targets this receptor is being tested at the NIH.[3]
[edit] External links
[edit] Interactions
CD22 has been shown to interact with Grb2,[4][5] PTPN6,[6][5][7][8][9] LYN,[4][7] SHC1[4] and INPP5D.[4]
[edit] References
- ^ Crocker et al.; Clark, EA; Filbin, M; Gordon, S; Jones, Y; Kehrl, JH; Kelm, S; Le Douarin, N et al. (1998). "Siglecs: a family of sialic-acid binding lectins". Glycobiology 8 (2): v. doi:10.1093/glycob/8.2.0. PMID 9498912.
- ^ Hatta et al. (1999). "Identification of the gene variations in human CD22". http://www.springerlink.com/content/cm72mmgn8npfpl00/.
- ^ "BL22 Immunotoxin in Treating Patients Previously Treated With Cladribine for Hairy Cell Leukemia". ClinicalTrials.gov - U.S. National Institutes of Health. http://clinicaltrials.gov/ct/show/NCT00074048. Retrieved 2008-02-19.
- ^ a b c d Poe, J C; Fujimoto M, Jansen P J, Miller A S, Tedder T F (Jun. 2000). "CD22 forms a quaternary complex with SHIP, Grb2, and Shc. A pathway for regulation of B lymphocyte antigen receptor-induced calcium flux". J. Biol. Chem. (UNITED STATES) 275 (23): 17420–7. doi:10.1074/jbc.M001892200. ISSN 0021-9258. PMID 10748054.
- ^ a b Otipoby, K L; Draves K E, Clark E A (Nov. 2001). "CD22 regulates B cell receptor-mediated signals via two domains that independently recruit Grb2 and SHP-1". J. Biol. Chem. (United States) 276 (47): 44315–22. doi:10.1074/jbc.M105446200. ISSN 0021-9258. PMID 11551923.
- ^ Blasioli, J; Paust S, Thomas M L (Jan. 1999). "Definition of the sites of interaction between the protein tyrosine phosphatase SHP-1 and CD22". J. Biol. Chem. (UNITED STATES) 274 (4): 2303–7. doi:10.1074/jbc.274.4.2303. ISSN 0021-9258. PMID 9890995.
- ^ a b Greer, S F; Justement L B (May. 1999). "CD45 regulates tyrosine phosphorylation of CD22 and its association with the protein tyrosine phosphatase SHP-1". J. Immunol. (UNITED STATES) 162 (9): 5278–86. ISSN 0022-1767. PMID 10228003.
- ^ Law, C L; Sidorenko S P, Chandran K A, Zhao Z, Shen S H, Fischer E H, Clark E A (Feb. 1996). "CD22 associates with protein tyrosine phosphatase 1C, Syk, and phospholipase C-gamma(1) upon B cell activation". J. Exp. Med. (UNITED STATES) 183 (2): 547–60. doi:10.1084/jem.183.2.547. ISSN 0022-1007. PMC 2192439. PMID 8627166. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2192439.
- ^ Adachi, T; Wienands J, Wakabayashi C, Yakura H, Reth M, Tsubata T (Jul. 2001). "SHP-1 requires inhibitory co-receptors to down-modulate B cell antigen receptor-mediated phosphorylation of cellular substrates". J. Biol. Chem. (United States) 276 (28): 26648–55. doi:10.1074/jbc.M100997200. ISSN 0021-9258. PMID 11356834.
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| 1-50 |
CD1 ( a-c, 1A, 1D, 1E) · CD2 · CD3 ( γ, δ, ε) · CD4 · CD5 · CD6 · CD7 · CD8 ( a) · CD9 · CD10 · CD11 ( a, b, c) · CD13 · CD14 · CD15 · CD16 ( A, B) · CD18 · CD19 · CD20 · CD21 · CD22 · CD23 · CD24 · CD25 · CD26 · CD27 · CD28 · CD29 · CD30 · CD31 · CD32 ( A, B) · CD33 · CD34 · CD35 · CD36 · CD37 · CD38 · CD39 · CD40 · CD41 · CD42 ( a, b, c, d) · CD43 · CD44 · CD45 · CD46 · CD47 · CD48 · CD49 ( a, b, c, d, e, f) · CD50
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| 51-100 |
CD51 · CD52 · CD53 · CD54 · CD55 · CD56 · CD57 · CD58 · CD59 · CD61 · CD62 ( E, L, P) · CD63 · CD64 ( A, B, C) · CD66 ( a, b, c, d, e, f) · CD68 · CD69 · CD70 · CD71 · CD72 · CD73 · CD74 · CD78 · CD79 ( a, b) · CD80 · CD81 · CD82 · CD83 · CD84 · CD85 ( a, d, e, h, j, k) · CD86 · CD87 · CD88 · CD89 · CD90 · CD91- CD92 · CD93 · CD94 · CD95 · CD96 · CD97 · CD98 · CD99 · CD100
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| 101-150 |
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| 151-200 |
CD151 · CD152 · CD153 · CD154 · CD155 · CD156 ( a, b, c) · CD157 · CD158 ( a, d, e, i, k) · CD159 ( a, c) · CD160 · CD161 · CD162 · CD163 · CD164 · CD166 · CD167 ( a, b) · CD168 · CD169 · CD170 · CD171 · CD172 ( a, b, g) · CD174 · CD177 · CD178 · CD179 ( a, b) · CD181 · CD182 · CD183 · CD184 · CD185 · CD186 · CD191 · CD192 · CD193 · CD194 · CD195 · CD196 · CD197 · CDw198 · CDw199 · CD200
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| 201-250 |
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| 251-300 |
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| 301-350 |
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Antibody receptor:
Fc receptor |
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| Antigen receptor |
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Antigen receptor
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Accessory molecules
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Antigen receptor
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Accessory molecules
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| Cytokine receptor |
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| Killer-cell IG-like receptors |
KIR2DL1, KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5A, KIR2DL5B, KIR2DS1, KIR2DS2, KIR2DS3, KIR2DS4, KIR2DS5, KIR3DL1, KIR3DL2, KIR3DL3, KIR3DS1
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| Leukocyte IG-like receptors |
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B trdu: iter (nrpl/grfl/cytl/horl), csrc (lgic, enzr, gprc, igsr, intg, nrpr/grfr/cytr), itra (adap, gbpr, mapk), calc, lipd; path (hedp, wntp, tgfp+mapp, notp, jakp, fsap, hipp, tlrp)
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