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1.
Braz. j. biol ; 83: e243910, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1278525

RESUMO

Abstract Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.


Resumo O reparo por excisão de nucleotídeos (NER) atua reparando danos no DNA, como lesões causadas por cisplatina. A proteína Xeroderma Pigmentosum complementation group C (XPC) está envolvida no reconhecimento de danos pela via de reparação global do genoma pelo NER (GG-NER) e tem sido estudada em diferentes organismos devido à sua importância em outros processos celulares. Neste trabalho, estudamos proteínas do NER em Trypanosoma cruzi e Trypanosoma evansi, parasitos de humanos e animais, respectivamente. Modelos tridimensionais das proteínas XPC de T. cruzi e T. evansi foram feitos e observou-se poucas diferenças estruturais entre estas proteínas. Durante testes, a inserção do gene XPC de T. evansi (TevXPC) em T. cruzi resultou em crescimento celular mais lento em condições normais. Após o tratamento com cisplatina, T. cruzi superexpressando seu próprio gene XPC (TcXPC) foi capaz de recuperar as taxas de divisão celular mais rapidamente do que T. cruzi expressando o gene TevXPC. Com base nesses testes, sugere-se que TevXPC (sendo uma proteína exógena em T. cruzi) interfere negativamente nos processos celulares em que TcXPC (a proteína endógena) está envolvida. Isso provavelmente ocorreu pois TevXPC é capaz de interagir com algumas moléculas ou proteínas endógenas de T.cruzi, mas é incapaz de interagir com outras. Isso reforça a importância do correto funcionamento de XPC dentro da célula.

2.
Braz J Biol ; 83: e243910, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34190757

RESUMO

Nucleotide excision repair (NER) acts repairing damages in DNA, such as lesions caused by cisplatin. Xeroderma Pigmentosum complementation group C (XPC) protein is involved in recognition of global genome DNA damages during NER (GG-NER) and it has been studied in different organisms due to its importance in other cellular processes. In this work, we studied NER proteins in Trypanosoma cruzi and Trypanosoma evansi, parasites of humans and animals respectively. We performed three-dimensional models of XPC proteins from T. cruzi and T. evansi and observed few structural differences between these proteins. In our tests, insertion of XPC gene from T. evansi (TevXPC) in T. cruzi resulted in slower cell growth under normal conditions. After cisplatin treatment, T. cruzi overexpressing its own XPC gene (TcXPC) was able to recover cell division rates faster than T. cruzi expressing TevXPC gene. Based on these tests, it is suggested that TevXPC (being an exogenous protein in T. cruzi) interferes negatively in cellular processes where TcXPC (the endogenous protein) is involved. This probably occurred due interaction of TevXPC with some endogenous molecules or proteins from T.cruzi but incapacity of interaction with others. This reinforces the importance of correctly XPC functioning within the cell.


Assuntos
Trypanosoma cruzi , Xeroderma Pigmentoso , Animais , Biologia Computacional , Dano ao DNA/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Trypanosoma cruzi/genética
3.
Gene ; 482(1-2): 1-7, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21497183

RESUMO

Corynebacterium spp. are a group of Gram-positive bacteria that includes plant and animal pathogens, nonpathogenic soil bacteria, and saprophytic species. Our understanding of these organisms is still poor compared with that of other bacterial organisms, but new insights offered by genome sequence data and the elucidation of gene content has provided clues about the nature, genome stability, pathogenicity and virulence of these organisms. We compared 15 Corynebacterium genomes, from pathogenic and nonpathogenic species, focusing on DNA repair genes. DNA repair is a mechanism of great importance in the maintenance of the genomic stability of any organism; inefficiency of this system can promote genomic instability and lead to death. This vulnerability makes it an interesting target in the study of means to control infectious organisms. We found that nucleotide excision repair (NER) was the only pathway whose involved genes were found in all species, suggesting that DNA integrity can be primarily maintained by NER. Recombination repair (RR) is also a well conserved pathway and most RR genes exist commonly in Corynebacterium spp. Absence of recCD genes was also shared by all species, contributing to prevent genome inversions and favoring genomic stability. Mismatch repair (MMR) appeared to be missing, although some genes in this pathway, such mutT, mutY and mutL, are present. Base excision repair (BER) and direct repair pathways are not conserved pathways, since the genes are not shared by all members; however, the existence of some seems to be enough to ensure pathway activity. An interesting fact is the persistence/acquisition of some repair genes in some species, suggesting an important role in DNA maintenance and evolution. These genes can be important targets in the investigation of the role of DNA repair in the pathogenicity of Corynebacterium species and be used as targets in therapeutic intervention. Phylogenetic analysis of uvrABC NER genes showed a pattern of clusters, in which most groups remained fixed. In general, the presence or inexistence of repair genes was shared by all the species we analyzed, and the loss or acquisition of certain DNA repair genes seems to have been an ancestral event.


Assuntos
Corynebacterium/genética , Reparo do DNA/genética , Modelos Genéticos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Dano ao DNA/genética , Reparo de Erro de Pareamento de DNA/genética , Genes Bacterianos/genética , Filogenia , Recombinação Genética
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