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An insight into the sialome of Simulium guianense (DIPTERA:SIMulIIDAE), the main vector of River Blindness Disease in Brazil.

Chagas AC, Calvo E, Pimenta PF, Ribeiro JM - BMC Genomics (2011)

Bottom Line: Insect-specific families were also found.About 63.4% of all secreted products revealed protein families found only in Simulium.Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway, National Institutes of Health, Rockville, Maryland 20892-8132, USA.

ABSTRACT

Background: Little is known about the composition and function of the saliva in black flies such as Simulium guianense, the main vector of river blindness disease in Brazil. The complex salivary potion of hematophagous arthropods counteracts their host's hemostasis, inflammation, and immunity.

Results: Transcriptome analysis revealed ubiquitous salivary protein families--such as the Antigen-5, Yellow, Kunitz domain, and serine proteases--in the S. guianense sialotranscriptome. Insect-specific families were also found. About 63.4% of all secreted products revealed protein families found only in Simulium. Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors. This study revealed a relative increase of transcripts of the SVEP protein family when compared with Simulium vittatum and S. nigrimanum sialotranscriptomes. We were able to extract coding sequences from 164 proteins associated with blood and sugar feeding, the majority of which were confirmed by proteome analysis.

Conclusions: Our results contribute to understanding the role of Simulium saliva in transmission of Onchocerca volvulus and evolution of salivary proteins in black flies. It also consists of a platform for mining novel anti-hemostatic compounds, vaccine candidates against filariasis, and immuno-epidemiologic markers of vector exposure.

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Phylogram of two Antigen-5 proteins derived from Simulium guianense sialotranscriptome with their best matches from the non-redundant protein database from the National Center for Biotechnology Information. The S. guianense proteins (Sg-457 and Sg-453) are indicates by a square, Simulium vittatum proteins by a triangle, and S. nigrimanum proteins by a circle. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 10% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor-joining algorithm. For other details, see Figure 3.
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Figure 6: Phylogram of two Antigen-5 proteins derived from Simulium guianense sialotranscriptome with their best matches from the non-redundant protein database from the National Center for Biotechnology Information. The S. guianense proteins (Sg-457 and Sg-453) are indicates by a square, Simulium vittatum proteins by a triangle, and S. nigrimanum proteins by a circle. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 10% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor-joining algorithm. For other details, see Figure 3.

Mentions: "This ubiquitous family belongs to the wider CAP superfamily [103]. Most members have no known function, but a few have been related to pathogen defenses in plants, as toxins in snake and lizard venoms [104,105], as a platelet aggregation inhibitor in a tabanid fly [106], and as a possible inhibitor of the classical pathway of complement activation in the stable fly [107,108]." Members of this family are found in all nematoceram sialotranscriptomes [67]. The annotated An. gambiae proteome reveals 21 proteins for this family, 2 of which are expressed in the SGs [64]. Similarly, the Ae. aegypti and C. quinquefasciatus proteome have over 30 members of the family, of which at least 2 are expressed in their SGs [25,68]. The S. guianense sialotranscriptome reveals two clusters coding for CAP family members. The phylogram resulting of the alignment of the two S. guianense proteins with their 25 best blastp matches from the NR protein database (excluding drosophilid proteins) reveals one clade of bloodsucking Nematocera with relatively strong bootstrap support (70%), and strong bootstrap support for the sub-clades containing each of the four families. Interestingly, all members of this clade (marked as "Salivary" in Figure 6) were found in sialotrancriptomes, suggesting a common salivary ancestor for this particular CAP-coding gene within Nematocera. The S. guianense protein Sg-453 is outside this clade and may represent an additional Simulium gene member of the CAP family that has been recruited for a salivary function. Thirty tryptic peptides deducted by MS/MS had matches for an Antigen-5 protein (Sg-457) within fraction 24, located just above the 28-kDa marked, near the predicted 30-kDa mature mol wt of this protein (Figure 2 and Table 4).


An insight into the sialome of Simulium guianense (DIPTERA:SIMulIIDAE), the main vector of River Blindness Disease in Brazil.

Chagas AC, Calvo E, Pimenta PF, Ribeiro JM - BMC Genomics (2011)

Phylogram of two Antigen-5 proteins derived from Simulium guianense sialotranscriptome with their best matches from the non-redundant protein database from the National Center for Biotechnology Information. The S. guianense proteins (Sg-457 and Sg-453) are indicates by a square, Simulium vittatum proteins by a triangle, and S. nigrimanum proteins by a circle. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 10% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor-joining algorithm. For other details, see Figure 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3285218&req=5

Figure 6: Phylogram of two Antigen-5 proteins derived from Simulium guianense sialotranscriptome with their best matches from the non-redundant protein database from the National Center for Biotechnology Information. The S. guianense proteins (Sg-457 and Sg-453) are indicates by a square, Simulium vittatum proteins by a triangle, and S. nigrimanum proteins by a circle. The numbers on the tree bifurcations indicate the percentage bootstrap support above 75%. The bar at the bottom represents 10% amino acid substitution. Protein sequences were aligned by the Clustal program, and the dendogram was made with the Mega package after 10 000 bootstraps with the neighbor-joining algorithm. For other details, see Figure 3.
Mentions: "This ubiquitous family belongs to the wider CAP superfamily [103]. Most members have no known function, but a few have been related to pathogen defenses in plants, as toxins in snake and lizard venoms [104,105], as a platelet aggregation inhibitor in a tabanid fly [106], and as a possible inhibitor of the classical pathway of complement activation in the stable fly [107,108]." Members of this family are found in all nematoceram sialotranscriptomes [67]. The annotated An. gambiae proteome reveals 21 proteins for this family, 2 of which are expressed in the SGs [64]. Similarly, the Ae. aegypti and C. quinquefasciatus proteome have over 30 members of the family, of which at least 2 are expressed in their SGs [25,68]. The S. guianense sialotranscriptome reveals two clusters coding for CAP family members. The phylogram resulting of the alignment of the two S. guianense proteins with their 25 best blastp matches from the NR protein database (excluding drosophilid proteins) reveals one clade of bloodsucking Nematocera with relatively strong bootstrap support (70%), and strong bootstrap support for the sub-clades containing each of the four families. Interestingly, all members of this clade (marked as "Salivary" in Figure 6) were found in sialotrancriptomes, suggesting a common salivary ancestor for this particular CAP-coding gene within Nematocera. The S. guianense protein Sg-453 is outside this clade and may represent an additional Simulium gene member of the CAP family that has been recruited for a salivary function. Thirty tryptic peptides deducted by MS/MS had matches for an Antigen-5 protein (Sg-457) within fraction 24, located just above the 28-kDa marked, near the predicted 30-kDa mature mol wt of this protein (Figure 2 and Table 4).

Bottom Line: Insect-specific families were also found.About 63.4% of all secreted products revealed protein families found only in Simulium.Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, 12735 Twinbrook Parkway, National Institutes of Health, Rockville, Maryland 20892-8132, USA.

ABSTRACT

Background: Little is known about the composition and function of the saliva in black flies such as Simulium guianense, the main vector of river blindness disease in Brazil. The complex salivary potion of hematophagous arthropods counteracts their host's hemostasis, inflammation, and immunity.

Results: Transcriptome analysis revealed ubiquitous salivary protein families--such as the Antigen-5, Yellow, Kunitz domain, and serine proteases--in the S. guianense sialotranscriptome. Insect-specific families were also found. About 63.4% of all secreted products revealed protein families found only in Simulium. Additionally, we found a novel peptide similar to kunitoxin with a structure distantly related to serine protease inhibitors. This study revealed a relative increase of transcripts of the SVEP protein family when compared with Simulium vittatum and S. nigrimanum sialotranscriptomes. We were able to extract coding sequences from 164 proteins associated with blood and sugar feeding, the majority of which were confirmed by proteome analysis.

Conclusions: Our results contribute to understanding the role of Simulium saliva in transmission of Onchocerca volvulus and evolution of salivary proteins in black flies. It also consists of a platform for mining novel anti-hemostatic compounds, vaccine candidates against filariasis, and immuno-epidemiologic markers of vector exposure.

Show MeSH
Related in: MedlinePlus