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Stage dependent regulation of trypanosome alternative oxidase (TAO) gene expression in Trypanosoma brucei
Author(s) -
Walker Robert Charles,
Chaudhuri Minu
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb31-c
Subject(s) - trypanosoma brucei , alternative oxidase , polyadenylation , mutant , luciferase , biology , untranslated region , three prime untranslated region , gene , microbiology and biotechnology , translation (biology) , messenger rna , biochemistry , transfection
African trypanosomes, like Trypanosoma brucei possesses a cytochrome‐independent terminal oxidase of mitochondrial electron transport chain, which is known as trypanosome alternative oxidase (TAO). The mammalian bloodstream form of T. brucei depends exclusively on TAO for their respiration. TAO expression is down regulated in the procyclic form, which grows in the insect vector. We have shown previously that TAO expression is regulated primarily at the level of transcript stability and de novo protein synthesis is required for transcript instability in the procyclic form. Here, we showed that the UTRs of the TAO transcript are responsible for its stage specific degradation pattern. TAO contains a long 3′‐UTR of about 2.2 Kb and a 5′‐UTR that is 125 bp. Deletion mutagenesis of the TAO 3′‐UTR revealed the presence of a cis‐element within the region of 500–1000 nt downstream of the stop codon that is responsible for destabilization of the luciferase reporter transcript in the procyclic form. Luciferase activity and the steady‐state level of the luciferase protein were unaltered in all these mutants. This indicates that possibly the shorter transcript produced by alternative polyadenylation possesses an increased efficiency for translation. This project was supported by MBRS SCORE 3SO6GM08037‐30S1 and NIH Minority Predoctoral Fellowship Grant 1F31GM077048