CTLA-4: Difference between revisions
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<StructureSection load='1i8l' size='340' side='right' caption='Human glycosylated CTLA-4 extracellular domain (deepskyblue) complex with CD80 (green) (PDB code [[1i8l]])' scene='83/836584/Cv/1'> | |||
<StructureSection load=' | |||
== Function ==CTLA4 is a member of the immunoglobulin superfamily that is expressed by activated T cells and transmits an inhibitory signal to T cells. CTLA4 is homologous to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells. CTLA-4 binds CD80 and CD86 with greater affinity and avidity than CD28 thus enabling it to outcompete CD28 for its ligands. CTLA4 transmits an inhibitory signal to T cells,[10][11][12][7] whereas CD28 transmits a stimulatory signal.[13][14] CTLA4 is also found in regulatory T cells (Tregs) and contributes to their inhibitory function. T cell activation through the T cell receptor and CD28 leads to increased expression of CTLA-4. | == Function == | ||
'''CTLA4''' or '''Cytotoxic T-Lymphocyte Associated protein 4''' or '''CD152''' is a member of the immunoglobulin superfamily that is expressed by activated T cells and transmits an inhibitory signal to T cells. CTLA4 is homologous to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells<ref>PMID:32185705</ref>. CTLA-4 binds CD80 and CD86 with greater affinity and avidity than CD28 thus enabling it to outcompete CD28 for its ligands. CTLA4 transmits an inhibitory signal to T cells,[10][11][12][7] whereas CD28 transmits a stimulatory signal.[13][14] CTLA4 is also found in regulatory T cells (Tregs) and contributes to their inhibitory function. T cell activation through the T cell receptor and CD28 leads to increased expression of CTLA-4. | |||
See also [[CTLA4 Gene (Protein Coding) Cytotoxic T-Lymphocyte Associated Protein 4]]. | |||
== Disease == | |||
Variants in this gene have been associated with Type 1 diabetes<ref>PMID:10671941</ref>, Graves' disease, Hashimoto's thyroiditis<ref>PMID:12914522</ref>, celiac disease, systemic lupus erythematosus, thyroid-associated orbitopathy, primary biliary cirrhosis and other autoimmune diseases. | |||
== Structural highlights == | == Structural highlights == | ||
The protein contains an extracellular V domain, a transmembrane domain, and a cytoplasmic tail. Alternate splice variants, encoding different isoforms, have been characterized. The membrane-bound isoform functions as a homodimer interconnected by a disulfide bond, while the soluble isoform functions as a monomer. The intracellular domain is similar to that of CD28. <scene name='83/836584/Cv/2'>The complex between CTLA-4 and CD80 is formed mostly by hydrophobic contacts</scene><ref>PMID:11279502</ref>. CTLA-4 residues are shown in ball-and-stick representation, while CD80 residues are in spacefill. | |||
</ | ==3D structures of CTLA-4== | ||
Updated on {{REVISIONDAY2}}-{{MONTHNAME|{{REVISIONMONTH}}}}-{{REVISIONYEAR}} | |||
[[2x44]], [[3osk]] - hCTLA-4 - human <br /> | |||
[[1ah1]] - hCTLA-4 - NMR<br /> | |||
[[5ggv]], [[5tru]], [[5xj3]], [[6rp8]], [[6xy2]], [[7dv4]], [[7elx]], [[7su0]], [[7su1]], [[8hit]], [[9dq3]] - hCTLA-4 + antibody <br /> | |||
[[6rpj]], [[6rqm]] - hCTLA-4 + nanobody <br /> | |||
[[1i8l]] - hCTLA-4 + CD80<br /> | |||
[[1i85]] - hCTLA-4 + CD86<br /> | |||
[[3bx7]] - hCTLA-4 + LCN2<br /> | |||
[[7cio]] - hCTLA-4 + PI3K<br /> | |||
[[4kkn]] - CTLA-4 - bovine<br /> | |||
[[1dqt]], [[5e56]] - mCTLA-4 - mouse<br /> | |||
[[5e5m]] - mCTLA-4 + nanobody <br /> | |||
[[9dq4]], [[9dq5]] - mCTLA-4 + antibody <br /> | |||
== References == | == References == | ||
<references/> | <references/> | ||
[[Category:Topic Page]] | |||
References https://www.wikiwand.com/en/CTLA-4 |