Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/10095
Title: Serine carboxypeptidases of Triatoma brasiliensis (Hemiptera, Reduviidae): Sequence characterization, expression pattern and activity localization
Authors: Waniek, Peter J
Araújo, Catarina A. C
Momoli, Marisa M
Azambuja, Patricia
Jansen, Ana Maria
Genta, Fernando A
Affilliation: Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia de Tripanossomatídeos. Rio de Janeiro, RJ, Brasil
FFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Bioquímica e Fisiologia de Insetos. Rio de Janeiro, RJ, Brasil.
Abstract: Using specific oligonucleotides, 50- and 30-RACE and sequencing, two cDNAs encoding serine carboxypeptidases (tbscp-1 and tbscp-2) from the midgut of the blood sucking heteropteran Triatoma brasiliensis were identified. Both cDNAs with an open reading frame of 1389 bp, encode serine carboxypeptidase precursors of 463 amino acid residues, which possess a signal peptide cleavage site after Ala19. Analysis of tbscp-1 and tbscp-2 genomic DNA showed an absence of introns in both sequences and the presence of a further intron-free SCP encoding gene (tbscp-2b). By reverse transcription polymerase chain reaction (RT-PCR), tbscp-1 and tbscp-2 transcript abundance was found similarly in fifth instar nymphs at different days after feeding (daf), high in the posterior midgut (small intestine), lower in the anterior midgut (stomach) and fat body and almost undetectable in the salivary glands. In the anterior, middle and posterior regions of the small intestine at 5 daf the transcript abundance of both genes was almost identical. Also in adult female and male insects at 5 daf both genes showed the strongest signal in the posterior midgut. Molecular modeling suggested that TBSCP-1 has carboxypeptidase D activity; activities against Hippuryl-Phenylalanine and Hippuryl-Arginine were also located at the posterior midgut, both were induced after blood feeding. Treatment of the posterior midgut extracts with the serine protease inhibitor PMSF strongly reduced carboxypeptidase activity. These findings suggest that triatomines might use serine carboxypeptidases, which are usually found in lysosomes, as digestive enzymes in the posterior midgut lumen, from which TBSCP-1 and TBSCP-2 are possible candidates to fulfill this function.
Keywords: Triatoma brasiliensis
Digestive enzymes
Serine carboxypeptidase
RT-PCR
Hematophagy
Keywords in spanish: Triatoma
keywords: Triatoma
Issue Date: 2014
Publisher: Elsevier
Citation: WANIEK, Peter J et al. Serine carboxypeptidases of Triatoma brasiliensis (Hemiptera, Reduviidae): Sequence characterization, expression pattern and activity localization. Journal of Insect Physiology. n.63, p.9-20, 2014.
DOI: 10.1016/j.jinsphys.2014.02.003
ISSN: 0022-1910
Copyright: restricted access
Appears in Collections:IOC - Artigos de Periódicos

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