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Genomic analyses, gene expression and antigenic profile of the trans-sialidase superfamily of Trypanosoma cruzi reveal an undetected level of complexity.

Freitas LM, dos Santos SL, Rodrigues-Luiz GF, Mendes TA, Rodrigues TS, Gazzinelli RT, Teixeira SM, Fujiwara RT, Bartholomeu DC - PLoS ONE (2011)

Bottom Line: We demonstrated that all seven groups represented in the array are antigenic.A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection.Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

ABSTRACT
The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a highly debilitating human pathology that affects millions of people in the Americas. The sequencing of this parasite's genome reveals that trans-sialidase/trans-sialidase-like (TcS), a polymorphic protein family known to be involved in several aspects of T. cruzi biology, is the largest T. cruzi gene family, encoding more than 1,400 genes. Despite the fact that four TcS groups are well characterized and only one of the groups contains active trans-sialidases, all members of the family are annotated in the T. cruzi genome database as trans-sialidase. After performing sequence clustering analysis with all TcS complete genes, we identified four additional groups, demonstrating that the TcS family is even more heterogeneous than previously thought. Interestingly, members of distinct TcS groups show distinctive patterns of chromosome localization. Members of the TcSgroupII, which harbor proteins involved in host cell attachment/invasion, are preferentially located in subtelomeric regions, whereas members of the largest and new TcSgroupV have internal chromosomal locations. Real-time RT-PCR confirms the expression of genes derived from new groups and shows that the pattern of expression is not similar within and between groups. We also performed B-cell epitope prediction on the family and constructed a TcS specific peptide array, which was screened with sera from T. cruzi-infected mice. We demonstrated that all seven groups represented in the array are antigenic. A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection. Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

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Related in: MedlinePlus

Multidimensional scaling (MDS) plot of the TcS protein sequences.The pairwise alignments of the 508 TcS complete members were performed and the distance matrix was used to generate a multidimensional scaling (MDS) plot. K-means method was used to define the clusters or groups. (A) Pattern of dispersion of all 508 TcS protein sequences resulting in 10 TcS groups. (B) Pattern of dispersion of 505 TcS protein sequences in eight TcS groups. Previously characterized TcS sequences were mapped on the MDS. TcSgroupI - blue; TcSgroupII - dark green; TcSgroupIII - light blue; TcSgroupIV - magenta; TcSgroupV - red; TcSgroupIV - gray; TcSgroupVII - orange and TcSgroupVIII - purple.
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pone-0025914-g001: Multidimensional scaling (MDS) plot of the TcS protein sequences.The pairwise alignments of the 508 TcS complete members were performed and the distance matrix was used to generate a multidimensional scaling (MDS) plot. K-means method was used to define the clusters or groups. (A) Pattern of dispersion of all 508 TcS protein sequences resulting in 10 TcS groups. (B) Pattern of dispersion of 505 TcS protein sequences in eight TcS groups. Previously characterized TcS sequences were mapped on the MDS. TcSgroupI - blue; TcSgroupII - dark green; TcSgroupIII - light blue; TcSgroupIV - magenta; TcSgroupV - red; TcSgroupIV - gray; TcSgroupVII - orange and TcSgroupVIII - purple.

Mentions: Despite the fact that four TcS groups were previously described [8], [13], [27], and only one group corresponds to the active trans-sialidase proteins, a much larger number of members of this gene family was annotated in public databases as trans-sialidases. To sort out which members correspond to the previously defined groups and to eventually identify new groups, we performed cluster analysis on all predicted TcS proteins identified in the CL Brener genome, excluding those annotated as partial and/or pseudogenes. A total of 508 TcS members were used to perform pairwise alignments resulting in a distance matrix that was used to generate a multidimensional scaling (MDS) plot (Figure 1). K-means method was then used to define ten clusters or groups (Figure 1A). Clustering with larger numbers of groups resulted in the fragmentation of previous clusters, without shuffling the members among them, indicating the robustness of the clustering of the family in ten groups (data not shown). Three members were located far from the others in the spatial distribution and therefore are the most divergent members of the family. One of them, Tc00.1047053505699.10, is the only representative of the group shown in black, and the Tc00.1047053509265.120 and Tc00.1047053507699.230 formed the brown group. Manual inspection of these three proteins revealed that their N-terminal regions are longer or shorter compared to the other TcS sequences: Tc00.1047053505699.10 contains an extra 260 amino acids at its N-terminal, whereas Tc00.1047053509265.120 and Tc00.1047053507699.230 have a deletion of approximately 160 and 450 amino acids, respectively, in their N-terminal region. The truncated sequences of these two proteins were due to the location of these genes in contig ends. Because gene prediction regarding the initial start codon could not be corrected for these three anomalous sequences, both black and brown groups were excluded from further analysis. The list of proteins belonging to each group is available in the supporting material (Table S3).


Genomic analyses, gene expression and antigenic profile of the trans-sialidase superfamily of Trypanosoma cruzi reveal an undetected level of complexity.

Freitas LM, dos Santos SL, Rodrigues-Luiz GF, Mendes TA, Rodrigues TS, Gazzinelli RT, Teixeira SM, Fujiwara RT, Bartholomeu DC - PLoS ONE (2011)

Multidimensional scaling (MDS) plot of the TcS protein sequences.The pairwise alignments of the 508 TcS complete members were performed and the distance matrix was used to generate a multidimensional scaling (MDS) plot. K-means method was used to define the clusters or groups. (A) Pattern of dispersion of all 508 TcS protein sequences resulting in 10 TcS groups. (B) Pattern of dispersion of 505 TcS protein sequences in eight TcS groups. Previously characterized TcS sequences were mapped on the MDS. TcSgroupI - blue; TcSgroupII - dark green; TcSgroupIII - light blue; TcSgroupIV - magenta; TcSgroupV - red; TcSgroupIV - gray; TcSgroupVII - orange and TcSgroupVIII - purple.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3198458&req=5

pone-0025914-g001: Multidimensional scaling (MDS) plot of the TcS protein sequences.The pairwise alignments of the 508 TcS complete members were performed and the distance matrix was used to generate a multidimensional scaling (MDS) plot. K-means method was used to define the clusters or groups. (A) Pattern of dispersion of all 508 TcS protein sequences resulting in 10 TcS groups. (B) Pattern of dispersion of 505 TcS protein sequences in eight TcS groups. Previously characterized TcS sequences were mapped on the MDS. TcSgroupI - blue; TcSgroupII - dark green; TcSgroupIII - light blue; TcSgroupIV - magenta; TcSgroupV - red; TcSgroupIV - gray; TcSgroupVII - orange and TcSgroupVIII - purple.
Mentions: Despite the fact that four TcS groups were previously described [8], [13], [27], and only one group corresponds to the active trans-sialidase proteins, a much larger number of members of this gene family was annotated in public databases as trans-sialidases. To sort out which members correspond to the previously defined groups and to eventually identify new groups, we performed cluster analysis on all predicted TcS proteins identified in the CL Brener genome, excluding those annotated as partial and/or pseudogenes. A total of 508 TcS members were used to perform pairwise alignments resulting in a distance matrix that was used to generate a multidimensional scaling (MDS) plot (Figure 1). K-means method was then used to define ten clusters or groups (Figure 1A). Clustering with larger numbers of groups resulted in the fragmentation of previous clusters, without shuffling the members among them, indicating the robustness of the clustering of the family in ten groups (data not shown). Three members were located far from the others in the spatial distribution and therefore are the most divergent members of the family. One of them, Tc00.1047053505699.10, is the only representative of the group shown in black, and the Tc00.1047053509265.120 and Tc00.1047053507699.230 formed the brown group. Manual inspection of these three proteins revealed that their N-terminal regions are longer or shorter compared to the other TcS sequences: Tc00.1047053505699.10 contains an extra 260 amino acids at its N-terminal, whereas Tc00.1047053509265.120 and Tc00.1047053507699.230 have a deletion of approximately 160 and 450 amino acids, respectively, in their N-terminal region. The truncated sequences of these two proteins were due to the location of these genes in contig ends. Because gene prediction regarding the initial start codon could not be corrected for these three anomalous sequences, both black and brown groups were excluded from further analysis. The list of proteins belonging to each group is available in the supporting material (Table S3).

Bottom Line: We demonstrated that all seven groups represented in the array are antigenic.A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection.Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

ABSTRACT
The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a highly debilitating human pathology that affects millions of people in the Americas. The sequencing of this parasite's genome reveals that trans-sialidase/trans-sialidase-like (TcS), a polymorphic protein family known to be involved in several aspects of T. cruzi biology, is the largest T. cruzi gene family, encoding more than 1,400 genes. Despite the fact that four TcS groups are well characterized and only one of the groups contains active trans-sialidases, all members of the family are annotated in the T. cruzi genome database as trans-sialidase. After performing sequence clustering analysis with all TcS complete genes, we identified four additional groups, demonstrating that the TcS family is even more heterogeneous than previously thought. Interestingly, members of distinct TcS groups show distinctive patterns of chromosome localization. Members of the TcSgroupII, which harbor proteins involved in host cell attachment/invasion, are preferentially located in subtelomeric regions, whereas members of the largest and new TcSgroupV have internal chromosomal locations. Real-time RT-PCR confirms the expression of genes derived from new groups and shows that the pattern of expression is not similar within and between groups. We also performed B-cell epitope prediction on the family and constructed a TcS specific peptide array, which was screened with sera from T. cruzi-infected mice. We demonstrated that all seven groups represented in the array are antigenic. A highly reactive peptide occurs in sixty TcS proteins including members of two new groups and may contribute to the known cross-reactivity of T. cruzi epitopes during infection. Taken together, our results contribute to a better understanding of the real complexity of the TcS family and open new avenues for investigating novel roles of this family during T. cruzi infection.

Show MeSH
Related in: MedlinePlus