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A novel ABCG-like transporter of Trypanosoma cruzi is involved in natural resistance to benznidazole.

Zingales B, Araujo RG, Moreno M, Franco J, Aguiar PH, Nunes SL, Silva MN, Ienne S, Machado CR, Brandão A - Mem. Inst. Oswaldo Cruz (2015)

Bottom Line: CL Brener transfected with TcI transporter genes showed 40-47% increased resistance to BZ, whereas no statistical significant increment in drug resistance was observed when CL Brener was transfected with the homologous gene.The analysis in wild type strains also suggests that the level of TcABCG1 transporter is related to BZ natural resistance.The characteristics of untranslated regions of TcABCG1 genes of BZ-susceptible and resistant strains were investigated by computational tools.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brasil.

ABSTRACT
Benznidazole (BZ) is one of the two drugs used for Chagas disease treatment. Nevertheless therapeutic failures of BZ have been reported, which were mostly attributed to variable drug susceptibility among Trypanosoma cruzi strains. ATP-binding cassette (ABC) transporters are involved in a variety of translocation processes and some members have been implicated in drug resistance. Here we report the characterisation of the first T. cruzi ABCG transporter gene, named TcABCG1, which is over-expressed in parasite strains naturally resistant to BZ. Comparison of TcABCG1 gene sequence of two TcI BZ-resistant strains with CL Brener BZ-susceptible strain showed several single nucleotide polymorphisms, which determined 11 amino acid changes. CL Brener transfected with TcI transporter genes showed 40-47% increased resistance to BZ, whereas no statistical significant increment in drug resistance was observed when CL Brener was transfected with the homologous gene. Only in the parasites transfected with TcI genes there was 2-2.6-fold increased abundance of TcABCG1 transporter protein. The analysis in wild type strains also suggests that the level of TcABCG1 transporter is related to BZ natural resistance. The characteristics of untranslated regions of TcABCG1 genes of BZ-susceptible and resistant strains were investigated by computational tools.

No MeSH data available.


Related in: MedlinePlus

protein sequence of TcABCG1 transporter (665 residues)encoded by CL Brener NEsmo haplotype. Rectangle blue, Walker A motif, green,ABC signature and purple, Walker B motif. The putative localisation of the sixα-helices is underlined; B: secondary structure of TcABCG1predicted with the SOSUI system (harrier.nagahama-i-bio.ac.jp/sosui/). Thelocalisation of nucleotide binding domain (NBD), membrane (M) and transmembranedomain (TMD) is indicated. Within the NBD, Walker A motif, ABC signature andWalker B motif are indicated as above. In the TMD, the six α-helices are shownin grey. Red circles denote the amino acid residues that differ between TcIstrains and NEsmo (Table II).
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f01: protein sequence of TcABCG1 transporter (665 residues)encoded by CL Brener NEsmo haplotype. Rectangle blue, Walker A motif, green,ABC signature and purple, Walker B motif. The putative localisation of the sixα-helices is underlined; B: secondary structure of TcABCG1predicted with the SOSUI system (harrier.nagahama-i-bio.ac.jp/sosui/). Thelocalisation of nucleotide binding domain (NBD), membrane (M) and transmembranedomain (TMD) is indicated. Within the NBD, Walker A motif, ABC signature andWalker B motif are indicated as above. In the TMD, the six α-helices are shownin grey. Red circles denote the amino acid residues that differ between TcIstrains and NEsmo (Table II).

Mentions: The identified ABC transporter gene (1,998 bp) is a single copy gene located onchromosome 37 of CL Brener (Weatherly et al.2009). The sequence of the transporter protein (665 residues), encoded by theNEsmo haplotype (XP_818614), and the secondary structure, predicted with the SOSUIsystem (harrier.nagahama-i-bio.ac.jp/sosui/), are shown in Fig. 1. According to this scheme (Fig. 1B), the NBD would be comprised between residues 1-~400. TheATP-binding site, spanning from residues 74-296, contains the Walker A, ABC signatureand Walker B motifs. The six presumed TMD α-helices are indicated in the Fig. 1. Based on these features, we concluded that thetransporter belongs to the half-size ABCG family (NBD-TMD structure arrangement). Beingthe first ABCG transporter to be characterised in T. cruzi it was namedTcABCG1.


A novel ABCG-like transporter of Trypanosoma cruzi is involved in natural resistance to benznidazole.

Zingales B, Araujo RG, Moreno M, Franco J, Aguiar PH, Nunes SL, Silva MN, Ienne S, Machado CR, Brandão A - Mem. Inst. Oswaldo Cruz (2015)

protein sequence of TcABCG1 transporter (665 residues)encoded by CL Brener NEsmo haplotype. Rectangle blue, Walker A motif, green,ABC signature and purple, Walker B motif. The putative localisation of the sixα-helices is underlined; B: secondary structure of TcABCG1predicted with the SOSUI system (harrier.nagahama-i-bio.ac.jp/sosui/). Thelocalisation of nucleotide binding domain (NBD), membrane (M) and transmembranedomain (TMD) is indicated. Within the NBD, Walker A motif, ABC signature andWalker B motif are indicated as above. In the TMD, the six α-helices are shownin grey. Red circles denote the amino acid residues that differ between TcIstrains and NEsmo (Table II).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4489481&req=5

f01: protein sequence of TcABCG1 transporter (665 residues)encoded by CL Brener NEsmo haplotype. Rectangle blue, Walker A motif, green,ABC signature and purple, Walker B motif. The putative localisation of the sixα-helices is underlined; B: secondary structure of TcABCG1predicted with the SOSUI system (harrier.nagahama-i-bio.ac.jp/sosui/). Thelocalisation of nucleotide binding domain (NBD), membrane (M) and transmembranedomain (TMD) is indicated. Within the NBD, Walker A motif, ABC signature andWalker B motif are indicated as above. In the TMD, the six α-helices are shownin grey. Red circles denote the amino acid residues that differ between TcIstrains and NEsmo (Table II).
Mentions: The identified ABC transporter gene (1,998 bp) is a single copy gene located onchromosome 37 of CL Brener (Weatherly et al.2009). The sequence of the transporter protein (665 residues), encoded by theNEsmo haplotype (XP_818614), and the secondary structure, predicted with the SOSUIsystem (harrier.nagahama-i-bio.ac.jp/sosui/), are shown in Fig. 1. According to this scheme (Fig. 1B), the NBD would be comprised between residues 1-~400. TheATP-binding site, spanning from residues 74-296, contains the Walker A, ABC signatureand Walker B motifs. The six presumed TMD α-helices are indicated in the Fig. 1. Based on these features, we concluded that thetransporter belongs to the half-size ABCG family (NBD-TMD structure arrangement). Beingthe first ABCG transporter to be characterised in T. cruzi it was namedTcABCG1.

Bottom Line: CL Brener transfected with TcI transporter genes showed 40-47% increased resistance to BZ, whereas no statistical significant increment in drug resistance was observed when CL Brener was transfected with the homologous gene.The analysis in wild type strains also suggests that the level of TcABCG1 transporter is related to BZ natural resistance.The characteristics of untranslated regions of TcABCG1 genes of BZ-susceptible and resistant strains were investigated by computational tools.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brasil.

ABSTRACT
Benznidazole (BZ) is one of the two drugs used for Chagas disease treatment. Nevertheless therapeutic failures of BZ have been reported, which were mostly attributed to variable drug susceptibility among Trypanosoma cruzi strains. ATP-binding cassette (ABC) transporters are involved in a variety of translocation processes and some members have been implicated in drug resistance. Here we report the characterisation of the first T. cruzi ABCG transporter gene, named TcABCG1, which is over-expressed in parasite strains naturally resistant to BZ. Comparison of TcABCG1 gene sequence of two TcI BZ-resistant strains with CL Brener BZ-susceptible strain showed several single nucleotide polymorphisms, which determined 11 amino acid changes. CL Brener transfected with TcI transporter genes showed 40-47% increased resistance to BZ, whereas no statistical significant increment in drug resistance was observed when CL Brener was transfected with the homologous gene. Only in the parasites transfected with TcI genes there was 2-2.6-fold increased abundance of TcABCG1 transporter protein. The analysis in wild type strains also suggests that the level of TcABCG1 transporter is related to BZ natural resistance. The characteristics of untranslated regions of TcABCG1 genes of BZ-susceptible and resistant strains were investigated by computational tools.

No MeSH data available.


Related in: MedlinePlus