Browsing by Issue Date, starting with "2001-11"
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- Microtubule cytoskeleton perturbation induced by taxol and colchicine affects chaperonin containing TCP-1 (CCT) subunit gene expression in Tetrahymena cellsPublication . Casalou, Cristina; Cyrne, Luísa; Rosa, Mónica Roxo; Soares, HelenaWe report the existence of a CCTϵ subunit gene that encodes subunit ϵ of the chaperonin CCT (chaperonin containing TCP-1) in Tetrahymena pyriformis. This work focuses on the study of the effects of the microtubule polymerizing agent taxol and the depolymerizing agent colchicine on microtubule dynamics and their role in the regulation of tubulin and CCT subunit genes. Under taxol treatment some TpCCT and tubulin genes are distinctly expressed until 30 min of treatment. Cytoplasmic TpCCT mRNA levels slightly decrease while tubulin transcripts are increasing. In colchicine treated cells TpCCT and tubulin transcripts decrease in the initial 30 min of treatment and then start to increase. However, both antimitotic agents induce TpCCT and tubulin gene transcription. This induction does not correlate with increased steady-state levels of TpCCT proteins and seems to be necessary to replete cytoplasmic TpCCT mRNAs. Moreover, we found that TpCCTϵ and TpCCTα but not TpCCTη are present in the insoluble fraction after a postmitochondrial fractionation that contains components of the ciliate cortex structure, basal bodies and cilia. This suggests that some TpCCT subunits may be associated with these structures. The association of TpCCTϵ subunit is stimulated either by taxol or colchicine treatment. These observations support the idea that CCT subunits could have additional roles in vivo.
- Saturação publicitáriaPublication . Verissimo, JorgeÉ logo pela manhã que a publicidade entra nas nossas vidas. Ainda em casa recebemo-la pela rádio, ou pela TV. Em direcção do emprego continua presente ainda na rádio, ou estática ao longo das filas de trânsito. Já no escritório, ou no café surge triunfante na revista que, entretanto, folheamos. Até no email. Ao almoço toda a cidade está decorada pelo mobiliário urbano. À noite, novamente em casa, basta premir o botão da TV para que um homem, quadro dinâmico, herói ambicioso, ou uma mulher, eternamente jovem, bela e saudável, cujas encenações sugerem um conto de fadas, nos seduzam.