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CD26; dipeptidyl peptidase 4; dipeptidyl peptidase IV; DPP IV; T-cell activation antigen CD26; TP103; adenosine deaminase (ADA) complexing protein 2; ADABP (DPP4, ADCP2)
Identical to dipeptidyl peptidase IV (DPPIV) & ADA-complexing protein-2.
Function:
1) metabolizes incretins
2) binds extracellular adenosine deaminase
3) cofactor with CD4 for HIV entry into cells
4) removes N-terminal dipeptides sequentially from polypeptides having unsubstituted N-termini provided that the penultimate residue is proline
5) role in T-cell activation
6) release of an N-terminal dipeptide, Xaa-Yaa-|-Zaa-, from a polypeptide, preferentially when Yaa is Pro, provided Zaa is neither Pro nor hydroxyproline
Structure:
- homodimer or heterodimer with seprase (FAP)
- belongs to the peptidase S9B family, DPPIV subfamily
Compartment:
- cell membrane
- dipeptidyl peptidase 4 soluble form: secreted
- derives from the membrane form by proteolytic processing
Expression:
- activated T cells & B cells
- NK cells
- macrophages
- renal proximal tubular epithelial cells
- small intestinal epithelium
- expressed in poorly differentiated crypt cells of small intestine as well as in mature villous cells
- expressed at very low levels in the colon
- biliary canaliculae
- splenic sinus lining cells
Pathology:
- peripheral blood T cells of patients with mycosis fungoides stain weakly to negative with antibody
Pharmacology:
- inhibitors of DPP4 (gliptins) are used for treatment of type 2 diabetes
Related
adenosine deaminase (adenosine aminohydrolase, ADA)
gliptin; dipeptidyl peptidase-4 inhibitor; DPP-4 inhibitor
T lymphocyte (T-cell, thymocyte)
General
cluster-of-differentiation antigen; cluster designation antigen; CD antigen
dipeptidyl peptidase (DPP)
plasma membrane protein
Properties
SIZE: entity length = 766 aa
MW = 88 kD
COMPARTMENT: cellular membrane
MOTIF: transmembrane domain {7-28}
N-glycosylation site {N85}
N-glycosylation site {N92}
N-glycosylation site {N150}
N-glycosylation site {N219}
N-glycosylation site {N229}
N-glycosylation site {N281}
N-glycosylation site {N321}
cysteine residue {C328}
MODIFICATION: cysteine residue {C339}
cysteine residue {C339}
MODIFICATION: cysteine residue {C328}
cysteine residue {C385}
MODIFICATION: cysteine residue {C394}
cysteine residue {C394}
MODIFICATION: cysteine residue {C385}
cysteine residue {C444}
MODIFICATION: cysteine residue {C447}
cysteine residue {C447}
MODIFICATION: cysteine residue {C444}
cysteine residue {C454}
MODIFICATION: cysteine residue {C472}
cysteine residue {C472}
MODIFICATION: cysteine residue {C454}
N-glycosylation site {N520}
serine residue {S630}
cysteine residue {C649}
MODIFICATION: cysteine residue {C762}
N-glycosylation site {N685}
aspartate residue {D708}
histidine residue {H740}
cysteine residue {C762}
MODIFICATION: cysteine residue {C649}
Database Correlations
OMIM 102720
UniProt P27487
PFAM correlations
Entrez Gene 1803
Kegg hsa:1803
ENZYME 3.4.14.5
References
- Kameoka J et al
Direct association of adenosine deaminase with a T cell
activation antigen CD26
Science 261:466 1993
PMID: 8101391
- OMIM :accession 102710
- http://www.pathologyoutlines.com/cdmarkers.html
15 October 2002
- Wikipedia; Note: dipeptidyl peptidase-4 entry
http://en.wikipedia.org/wiki/dipeptidyl_peptidase-4
- UniProt :accession P27487