IDO1
IDO1 (indoleamine 2,3-dioxygenase 1, also known as IDO or INDO) is a cytosolic heme enzyme that catalyses the first, rate-limiting step of tryptophan catabolism along the kynurenine pathway. Through this activity it shapes immune tolerance, antitumour immunity and host defence. Browse Assay Genie's current range of IDO1 research reagents below, or read on for the biology behind the target.
IDO1 is a heme enzyme that catalyses the first and rate-limiting step in the catabolism of the essential amino acid tryptophan along the kynurenine pathway, producing N-formyl-kynurenine. It acts on several substrates, including D-tryptophan, L-tryptophan, 5-hydroxy-tryptophan, tryptamine and serotonin. By depleting tryptophan and generating tryptophan catabolites, IDO1 influences the behaviour of neighbouring immune cells.
This effect is central to its role in peripheral immune tolerance. Tryptophan shortage inhibits T lymphocyte division, while accumulation of tryptophan catabolites induces T-cell apoptosis and promotes differentiation of regulatory T-cells. In this way IDO1 helps maintain homeostasis by preventing the autoimmunity or immunopathology that could result from uncontrolled, overreactive immune responses. It is expressed in dendritic cells, monocytes and macrophages, where it modulates T-cell behaviour through peri-cellular catabolism of tryptophan. It has also been described as protecting the fetus from maternal immune rejection.
The same mechanism has wider consequences. IDO1 acts as a suppressor of anti-tumour immunity, and it limits the growth of intracellular pathogens by depriving them of tryptophan. The enzyme is also thought to contribute to neuropathology and antioxidant activity. The IDO1 gene encodes a 403-residue cytosolic protein belonging to the indoleamine 2,3-dioxygenase family; earlier literature uses the names IDO, INDO and indoleamine-pyrrole 2,3 dioxygenase. Mouse and rat each carry an Ido1 ortholog.
IDO1 acts as a suppressor of anti-tumour immunity, making it a focus for studies of immune evasion and tumour microenvironments.
Tryptophan depletion and kynurenine-pathway catabolites restrain T-cell division and favour regulatory T-cells, so IDO1 is central to tolerance research.
IDO1 limits the growth of intracellular pathogens by depriving them of tryptophan, linking it to antimicrobial defence.
IDO1 is reported to protect the fetus from maternal immune rejection, an area of interest in reproductive immunology.
IDO1 catalyses the first and rate-limiting step of tryptophan catabolism along the kynurenine pathway. Tryptophan shortage inhibits T lymphocyte division, and its catabolites induce T-cell apoptosis and regulatory T-cell differentiation, supporting immune tolerance. Check the datasheet of any product for its validated reactivity.
IDO1 is the HGNC-approved symbol for indoleamine 2,3-dioxygenase 1. Aliases and previous symbols include IDO and INDO, and an earlier protein name was indoleamine-pyrrole 2,3 dioxygenase. The enzyme belongs to the indoleamine 2,3-dioxygenase family and carries EC number 1.13.11.52.
Yes. Both mouse and rat have an ortholog named Ido1. The human enzyme is linked to antimicrobial and antitumour defence, immunoregulation and foetal protection from maternal immune rejection, which makes rodent models useful for studying these processes.
Other tryptophan-catabolism enzymes, immune checkpoint proteins and regulators of T-cell tolerance with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P14902; product specifications from Assay Genie datasheets.