Your browser doesn't support javascript.
Role of a Stem-Loop Structure in Helicobacter pylori cagA Transcript Stability.
Infect Immun ; 87(2)2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30510104
Helicobacter pylori CagA is a secreted effector protein that contributes to gastric carcinogenesis. Previous studies showed that there is variation among H. pylori strains in the steady-state levels of CagA and that a strain-specific motif downstream of the cagA transcriptional start site (the +59 motif) is associated with both high levels of CagA and premalignant gastric histology. The cagA 5' untranslated region contains a predicted stem-loop-forming structure adjacent to the +59 motif. In the current study, we investigated the effect of the +59 motif and the adjacent stem-loop on cagA transcript levels and cagA mRNA stability. Using site-directed mutagenesis, we found that mutations predicted to disrupt the stem-loop structure resulted in decreased steady-state levels of both the cagA transcript and the CagA protein. Additionally, these mutations resulted in a decreased cagA mRNA half-life. Mutagenesis of the +59 motif without altering the stem-loop structure resulted in reduced steady-state cagA transcript and CagA protein levels but did not affect cagA transcript stability. cagA transcript stability was not affected by increased sodium chloride concentrations, an environmental factor known to augment cagA transcript levels and CagA protein levels. These results indicate that both a predicted stem-loop structure and a strain-specific +59 motif in the cagA 5' untranslated region influence the levels of cagA expression.





Texto completo: Disponível Coleções: Bases de dados internacionais Base de dados: MEDLINE Assunto principal: Proteínas de Bactérias / DNA Bacteriano / RNA Mensageiro / Helicobacter pylori / Infecções por Helicobacter / Estabilidade de RNA / Antígenos de Bactérias Aspecto clínico: Predição / Prognóstico Limite: Humanos Idioma: Inglês Ano de publicação: 2019 Tipo de documento: Artigo País de afiliação: Estados Unidos