Different partners, opposite outcomes: a new perspective of the immunobiology of indoleamine 2,3-dioxygenase.
Indoleamine 2,3-dioxygenase (IDO), a metabolic enzyme that catalyzes tryptophan conversion into kynurenines, is a crucial regulator of immunity. Altered IDO activity is often associated with pathology, including neoplasia and autoimmunity. IDO is highly expressed in dendritic cells (DCs) that exploit the enzyme's activity and the production of tryptophan catabolites to regulate immune responses by acting on several cell types, including T lymphocytes, of which they promote a regulatory phenotype. IDO also contains immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that, once bound by distinct molecular partners, will either promote degradation or initiate signaling activity and self-maintenance of the enzyme. We here discuss how ITIM-dependent molecular events can affect the functional plasticity of IDO by modifying the protein half-life and its enzymic and nonenzymic functions.
Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy. email@example.com
SourceMolecular medicine (Cambridge, Mass.) 18: 2012 pg 834-42
MeSHAmino Acid Motifs
Gene Expression Regulation
I-kappa B Kinase
Interleukin-1 Receptor-Associated Kinases
Protein Tyrosine Phosphatase, Non-Receptor Type 11
Protein Tyrosine Phosphatase, Non-Receptor Type 6
Proto-Oncogene Proteins c-fyn
Transforming Growth Factor beta
Pub Type(s)Journal Article
Research Support, Non-U.S. Gov't