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CD28; T-cell-specific surface glycoprotein CD28; TP44

Function: - CD28 binds to & is activated by B-7 (CD80), an Ig-like protein on the surface of antigen-presenting cells - the interaction of CD28 with B-7 is necessary in addition to stimulation of the T-cell receptor for production of IL-2 in quiescent T-cells - CD28 associates with & activates lck & fyn [2] - Tyr-173 phosphorylation allows recruitment of signalling proteins including phosphatidylinositol-3-kinase, GRB2 & GRAP2 through SH2 domains - interacts with DUSP14 - binds to CD80 (B-7) & CD86 Structure: - homodimer; disulfide-linked. - contains 1 Ig-like V-type domain (immunoglobulin-like) Compartment: membrane Alternative splicing: named isoforms=6 Expression: - CD4+ T cells ~95% - CD8+ T cells ~50% - activated B cells - plasma cells

General

adhesion receptor cluster-of-differentiation antigen; cluster designation antigen; CD antigen glycoprotein immunoglobulin superfamily protein

Properties

SIZE: entity length = 220 aa MW = 25 kD COMPARTMENT: cellular membrane MOTIF: signal sequence {1-18} immunoglobulin superfamily domain {28-137} MOTIF: N-glycosylation site {N37} cysteine residue {C40} MODIFICATION: cysteine residue {C112} cysteine residue {C66} MODIFICATION: cysteine residue {C86} N-glycosylation site {N71} cysteine residue {C86} MODIFICATION: cysteine residue {C66} N-glycosylation site {N92} N-glycosylation site {N105} cysteine residue {C112} MODIFICATION: cysteine residue {C40} N-glycosylation site {N129} transmembrane domain {153-179} Tyr phosphorylation site {Y191} Tyr phosphorylation site {Y209}

References

  1. Turka LA, Ledbetter JA, Lee K, June CH, Thompson CB. CD28 is an inducible T cell surface antigen that transduces a proliferative signal in CD3+ mature thymocytes. J Immunol. 1990 Mar 1;144(5):1646-53. PMID: 2155264
  2. Bolen JB, Rowley RB, Spana C, Tsygankov AY. The Src family of tyrosine protein kinases in hemopoietic signal transduction. FASEB J. 1992 Dec;6(15):3403-9. Review. PMID: 1281458
  3. Pawson T Protein modules and signalling networks Nature 373:573 1995 PMID: 7531822
  4. http://www.pathologyoutlines.com/cdmarkers.html 15 October 2002
  5. Entrez Gene :accession 940
  6. Wikipedia; Note: CD28 entry http://en.wikipedia.org/wiki/CD28
  7. UniProt :accession P10747

Databases & Figures

OMIM 186760 UniProt P10747 Entrez Gene 940 Kegg hsa:940 TNFR/IL1R1/CD28/TCR-CD3 -> NF kappa B