1DQT,1I8L,1AH1


Conserved Protein Domain Family
IgV_CTLA-4

?
cd05721: IgV_CTLA-4 
Immunoglobulin Variable (IgV) domain of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4)
The members here are composed of the variable(v)-type immunoglobulin (Ig) domain found in cytotoxic T lymphocyte-associated antigen 4 (CTLA-4). CTLA-4 is involved in the regulation of T cell response, acting as an inhibitor of intracellular signaling. CTLA-4 is similar to CD28, a T cell co-receptor protein that recognizes the B7 proteins (CD80 and CD86). CD28 binding of the B7 proteins occurs after the presentation of antigen to the T cell receptor (TCR) via the peptide-MHC complex on the surface of an antigen presenting cell (APC). CTLA-4 also binds the B7 molecules with a higher affinity than does CD28. The B7/CTLA-4 interaction generates inhibitory signals down-regulating the response, and may prevent T cell activation by weak TCR signals. CD28 and CTLA-4 then elicit opposing signals in the regulation of T cell responsiveness and homeostasis. T cell activation leads to increased CTLA-4 gene expression and trafficking of CTLA-4 protein to the cell surface. CTLA-4 is not detected on the T-cell surface until 24 hours after activation. Covalent dimerization of CTLA-4 has been shown to be required for its high binding avidity, although each CTLA-4 monomer contains a binding site for CD80 and CD86.
Statistics
?
PSSM-Id: 409386
View PSSM: cd05721
Aligned: 5 rows
Threshold Bit Score: 237.59
Threshold Setting Gi: 11514259
Created: 10-Sep-2007
Updated: 17-Aug-2020
Structure
?
Program:
Drawing:
Aligned Rows:
  next features
Conserved site includes 4 residues -Click on image for an interactive view with Cn3D
Feature 1:antigen binding site [polypeptide binding site]
Evidence:
  • Structure:1I8L_C; human CTLA4 binds to antigen B7-1, defined by 3.5A distance.
    View structure with Cn3D
  • Comment:B7-1/CTLA4 complex inhibits immune response.

Sequence Alignment
?
Format: Row Display: Color Bits: Type Selection:
Feature 1                                                                                        
1DQT_A         2 QVTQPSVVLASSHGVASFPCEYSPSHNTDEVRVTVLRQTNDQMTEVCATTFTEKNTVGFLDYPFCSGTFNESRVNLTIQG 81  house mouse
1I8L_C         4 HVAQPAVVLASSRGIASFVCEYASPGKATEVRVTVLRQADSQVTEVCAATYMMGNELTFLDDSICTGTSSGNQVNLTIQG 83  human
1AH1_A         3 HVAQPAVVLASSRGIASFVCEYASPGKATEVRVTVLRQADSQVTEVCAATYMMGNELTFLDDSICTGTSSGNQVNLTIQG 82  human
NP_001009236  39 HVAQPAVVLASSRGVASFVCEYGSSGNAAEVRVTVLRQTGSQMTEVCAATYTVENELAFLDDSTCTGISSGNKVNLTIQG 118 Felis catus
AAF23813      39 HVAQPAVVLASSRGVASFVCEYGSSGNAAEVRVTVLRQAGSQMTEVCAATYTVEDELAFLDDSTCTGTSSGNKVNLTIQG 118 Canis lupus fam...
Feature 1                       ##  ##              
1DQT_A        82 LRAVDTGLYLCKVELMYPPPYFVGMGNGTQIYVID 116 house mouse
1I8L_C        84 LRAMDTGLYICKVELMYPPPYYLGIGNGAQIYVID 118 human
1AH1_A        83 LRAMDTGLYICKVELMYPPPYYLGIGNGTQIYVID 117 human
NP_001009236 119 LRAMDTGLYICKVELMYPPPYYAGMGNGTQIYVID 153 Felis catus
AAF23813     119 LRAMDTGLYICKVELMYPPPYYVGMGNGTQIYVID 153 Canis lupus familiaris

| Disclaimer | Privacy statement | Accessibility |
NCBI Home NCBI Search NCBI SiteMap