Disruption of the trypanothione reductase gene of Leishmania decreases its ability to survive oxidative stress in macrophages - PubMed (original) (raw)

Disruption of the trypanothione reductase gene of Leishmania decreases its ability to survive oxidative stress in macrophages

C Dumas et al. EMBO J. 1997.

Abstract

Parasitic protozoa belonging to the order Kinetoplastida contain trypanothione as their major thiol. Trypanothione reductase (TR), the enzyme responsible for maintaining trypanothione in its reduced form, is thought to be central to the redox defence systems of trypanosomatids. To investigate further the physiological role of TR in Leishmania, we attempted to create TR-knockout mutants by gene disruption in L. donovani and L. major strains using the selectable markers neomycin and hygromycin phosphotransferases. TR is likely to be an important gene for parasite survival since all our attempts to obtain a TR null mutant in L. donovani failed. Instead, we obtained mutants with a partial trisomy for the TR locus where, despite the successful disruption of two TR alleles by gene targeting, a third TR copy was generated as a result of genomic rearrangements involving the translocation of a TR-containing region to a larger chromosome. Mutants of L. donovani and L. major possessing only one wild-type TR allele express less TR mRNA and have lower TR activity compared with wild-type cells carrying two copies of the TR gene. Significantly, these mutants show attenuated infectivity with a markedly decreased capacity to survive intracellularly within macrophages, provided that the latter are producing reactive oxygen intermediates.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Cell. 1983 Jan;32(1):35-43 - PubMed
    1. Cell. 1981 Dec;27(3 Pt 2):497-505 - PubMed
    1. Proc Natl Acad Sci U S A. 1996 Sep 17;93(19):10383-7 - PubMed
    1. Exp Parasitol. 1997 Jan;85(1):35-42 - PubMed
    1. Proc Natl Acad Sci U S A. 1995 Oct 24;92(22):10267-71 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources