Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acquired immune deficiency syndrome (AIDS) is an incurable disease at present and so many efforts to conquer this disease are being made around the world. In studies of human immunodeficiency virus (HIV) infection and the disease progression, it has been reported that T cells expressing CD26 are preferentially infected and depleted in HIV-infected individuals. CD26 is a widely distributed 110 kDa cell-surface glycoprotein with known dipeptidyl peptidase IV (DPPIV) activity in its extracellular domain. This ectoenzyme is capable of cleaving N-terminal dipeptides from polypeptides with either proline or alanine residues in the penultimate position. On human T cells, CD26 exhibits the co-stimulatory function and plays an important role in immune response via its ability to bind adenosine deaminase (ADA) and association with CD45. Recent studies have been stripping the veil from over the relationship between CD26 and HIV infection. Susceptibility of cells to HIV infection is correlated with CD26 expression, and HIV transactivator Tat and envelope protein gp120 are reported to interact with CD26. These observations indicate that CD26 is closely involved in HIV cell entry and that CD26-mediated T cell immune response is suppressed. In addition, it has been demonstrated that the anti-HIV and chemotactic activities of RANTES (regulated on activation, normal T cell expressed and secreted) and stromal cell-derived factor-1 (SDF-1) are controlled with the DPPIV activity of CD26. Thus, the regulation of the function of chemokines by CD26/DPPIV appears to be essential for lymphocyte trafficking and infectivity of HIV strains.
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PMID:Good or evil: CD26 and HIV infection. 1069 52

Dipeptidyl peptidase IV (DPPIV or CD26) is a multifunctional membrane glycoprotein. As an exopeptidase it regulates the activity of a series of biologically important peptides. Through its interaction with specific proteins and peptides, DPPIV is also involved in a wide range of biologically relevant processes such as cell adhesion, T cell activation and apoptosis. In this paper, we review our recent studies on the interactions of DPPIV with adenosine deaminase (ADA) and the transcription transactivator of the human immunodeficiency virus type-1 (HIV-1 Tat) as revealed by three-dimensional structure reconstructed by single particle analysis of cryo-electron microscopy (EM) and crystal structures of the human DPPIV-bovine ADA complex as well as the crystal structures of DPPIV in complex with HIV-1 Tat-derived nonapeptides. These results contribute importantly to the clarification of the molecular mechanisms of this multifunctional protein. The biological relevance of these interactions is discussed.
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PMID:Molecular mechanism and structural basis of interactions of dipeptidyl peptidase IV with adenosine deaminase and human immunodeficiency virus type-1 transcription transactivator. 2185 36