Species Human Entrez 1803 | Human Mouse Ensembl ENSG00000197635 | |
 | ||
Aliases DPP4, ADABP, ADCP2, CD26, DPPIV, TP103, dipeptidyl peptidase 4 External IDs OMIM: 102720 MGI: 94919 HomoloGene: 3279 GeneCards: DPP4 | ||
Dipeptidyl peptidase 4 inhibitor
Dipeptidyl peptidase-4 (DPP4), also known as adenosine deaminase complexing protein 2 or CD26 (cluster of differentiation 26) is a protein that, in humans, is encoded by the DPP4 gene. DPP4 is related to attractin, FAP, DPP8 and DPP9.
Contents
Function
The protein encoded by the DPP4 gene is an antigenic enzyme expressed on the surface of most cell types and is associated with immune regulation, signal transduction and apoptosis. It is an intrinsic membrane glycoprotein and a serine exopeptidase that cleaves X-proline dipeptides from the N-terminus of polypeptides.
It is a rather indiscriminate enzyme for which a diverse range of substrates are known. The substrates of CD26/DPPIV are proline(or alanine)-containing peptides and include growth factors, chemokines, neuropeptides, and vasoactive peptides. DPP4 plays a major role in glucose metabolism. It is responsible for the degradation of incretins such as GLP-1. Furthermore, it appears to work as a suppressor in the development of cancer and tumours.
DPP-4 also binds the enzyme adenosine deaminase specifically and with high affinity. The significance of this interaction has yet to be established.
Animal studies
Animal studies suggest its pathogenetic role in development of fibrosis of various organs, such as liver and kidney.
Clinical significance
CD26/DPPIV plays an important role in tumor biology, and is useful as a marker for various cancers, with its levels either on the cell surface or in the serum increased in some neoplasms and decreased in others.
A new class of oral hypoglycemics called dipeptidyl peptidase-4 inhibitors work by inhibiting the action of this enzyme, thereby prolonging incretin effect in vivo.
A new coronavirus related to SARS, named Middle East respiratory syndrome coronavirus, has been found to bind to DPP4. DPP4 is found on the surface of cells in the airways (such as the lungs) and kidneys. Scientists may be able to use this to their advantage by blocking the virus's entry into the cell.