Limits...
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.

Show MeSH

Related in: MedlinePlus

Prototype of each TcS group.The motifs are shown only when they occur in the majority of the proteins within the group. The Asp-box and VTVxNVxLYNR logos are shown above each motif. The numbers within parentheses indicate the number of occurrences of a given motif. The length of the proteins within the groups may vary. Graphical representations are not to scale.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3198458&req=5

pone-0025914-g002: Prototype of each TcS group.The motifs are shown only when they occur in the majority of the proteins within the group. The Asp-box and VTVxNVxLYNR logos are shown above each motif. The numbers within parentheses indicate the number of occurrences of a given motif. The length of the proteins within the groups may vary. Graphical representations are not to scale.

Mentions: To characterize each of the eight groups, we initially searched for all the key signature motifs as they are described in the literature [8], [13] and mapped them into the MDS plot (Figure S2). The canonical VTVxNVxLYNR motif was found in only 328 of 508 TcS sequences used in this study. This result prompted us to investigate whether the other proteins annotated as TcS have a degenerate form of this motif or do not have this motif at all. To this end, we performed ClustalW alignment of all 508 TcS proteins and retrieved the alignment block containing this motif. Visual inspection of this region reveals that 159 sequences have a degenerate version of this motif. Hence, 487 (96%) of the TcS sequences have the canonical or degenerate forms of the VTVxNVxLYNR motif. The remaining sequences do not contain this motif because they have a truncated C-terminal region resulting from premature stop codons and/or frameshifts. Therefore, as previously described, this motif is a signature of the TcS family that is found in all its members. As shown in Figure 2, although variations on the VTVxNVxLYNR motif are observed, the motif is highly conserved within each cluster.


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)

Prototype of each TcS group.The motifs are shown only when they occur in the majority of the proteins within the group. The Asp-box and VTVxNVxLYNR logos are shown above each motif. The numbers within parentheses indicate the number of occurrences of a given motif. The length of the proteins within the groups may vary. Graphical representations are not to scale.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198458&req=5

pone-0025914-g002: Prototype of each TcS group.The motifs are shown only when they occur in the majority of the proteins within the group. The Asp-box and VTVxNVxLYNR logos are shown above each motif. The numbers within parentheses indicate the number of occurrences of a given motif. The length of the proteins within the groups may vary. Graphical representations are not to scale.
Mentions: To characterize each of the eight groups, we initially searched for all the key signature motifs as they are described in the literature [8], [13] and mapped them into the MDS plot (Figure S2). The canonical VTVxNVxLYNR motif was found in only 328 of 508 TcS sequences used in this study. This result prompted us to investigate whether the other proteins annotated as TcS have a degenerate form of this motif or do not have this motif at all. To this end, we performed ClustalW alignment of all 508 TcS proteins and retrieved the alignment block containing this motif. Visual inspection of this region reveals that 159 sequences have a degenerate version of this motif. Hence, 487 (96%) of the TcS sequences have the canonical or degenerate forms of the VTVxNVxLYNR motif. The remaining sequences do not contain this motif because they have a truncated C-terminal region resulting from premature stop codons and/or frameshifts. Therefore, as previously described, this motif is a signature of the TcS family that is found in all its members. As shown in Figure 2, although variations on the VTVxNVxLYNR motif are observed, the motif is highly conserved within each cluster.

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