Depletion of tryptophan is not involved in expression of tryptophanyl-tRNA synthetase mediated by interferon.
نویسندگان
چکیده
Gamma interferon (IFN-gamma) affects tryptophan metabolism by mediating the expression of indoleamine 2,3-dioxygenase and tryptophanyl-tRNA synthetase. In the present study, we investigated the role of indoleamine 2,3-dioxygenase-mediated tryptophan depletion in the induction of tryptophanyl-tRNA synthetase by IFN-gamma. The addition of excess tryptophan to the culture medium did not affect the induction of tryptophanyl-tRNA synthetase by IFN-gamma, indicating that tryptophan degradation is not directly involved in the IFN-gamma-mediated expression of tryptophanyl-tRNA synthetase.
منابع مشابه
Overproduction of tryptophanyl-tRNA synthetase relieves transcription termination at the Escherichia coli tryptophan operon attenuator.
Overproduction of tryptophanyl-tRNA synthetase increased trp operon expression by reducing transcription termination at the trp attenuator. The total cellular level of charged tRNATrp was not affected by increased levels of the synthetase. We propose that excess synthetase binds charged tRNATrp and reduces the concentration available for translation.
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I N addition to their role in protein synthesis, aminoacyl tRNA synthetases in bacteria have been shown to have a regulatory role in the formation of enzymes involved in the synthesis of corresponding amino acids. This has been demonstrated at least in the case of isoleucine and valine (EIDLIC and NEIDHARDT 1965; YANIV, JACOB and GROS 1965) and histidine (SCHLESINGER and MAGASANIK 1964; ROTH, A...
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Indoleamine-2,3-dioxygenase (IDO) and tryptophanyl-tRNA-synthetase (TTS) are interferon-gamma (IFN-gamma)-inducible enzymes that are responsible for tryptophan degradation and for its use in protein synthesis, respectively. IFN-gamma-induced IDO has immunomodulatory properties in murine and human models. A concomitant increase of TTS has been postulated to protect the IDO-expressing cells from ...
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ورودعنوان ژورنال:
- Infection and immunity
دوره 60 10 شماره
صفحات -
تاریخ انتشار 1992