Publicação
The role of endoplasmic reticulum-mitochondria contact sites and mitochondrial phospholipid composition in Saccharomyces cerevisiae acetic acid-induced apoptosis
| Resumo: | Endoplasmic reticulum-mitochondria contact sites (ERM-CS), found from yeast to mammals, are interface structures where membranes of the two organelles are maintained in close proximity by tethering protein complexes. These structures play a prominent role in the communication between the two organelles, including the transport of molecules and transmission of regulatory signals, and have been implicated in apoptotic signaling, though the exact mechanism is still unclear. In the present work we questioned if perturbation of ERM-CS could have a role in Saccharomyces cerevisiae acetic acidinduced apoptosis. We also aimed to assess if perturbation of mitochondrial phospholipid content resulting from deficiency in ERM-CS components or in proteins involved in phospholipid synthesis or transport could influence acetic acid-induced apoptosis. Cell viability assays and assessment of cytochrome c (cyt c) release carried in S. cerevisiae and in mutants affected in the above mentioned processes show that all the mutant strains, except those involved in cardiolipin biosynthesis and remodeling, display a delay in apoptotic cell death in response to acetic acid treatment related with an hindrance of cyt c release. Analysis of the phospholipid composition of mitochondria isolated from the strains under study, grown in glucose or in a less repressive carbon source, and treated or not with acetic acid, show different profiles between carbon sources and the different strains, and also after treatment with acetic acid. Knowing the important role of the ERMES complex in the mitochondrial metabolism, and to uncover if this complex could be involved in Bax mediated cell death, we transformed mutant strains deficient in each protein of this complex with Bax. Assessment of cell death induced by expression of Bax, suggested that there is no alteration in any of the transformed strains in comparison with the BY4741 phenotype, with the exception of one mutant, which showed a slight decrease in cell survival. However, further analysis is necessary to confirm these results. |
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| Autores principais: | Afonso, Catarina Barbeiro |
| Assunto: | Ciências Naturais::Ciências Biológicas |
| Ano: | 2016 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Endoplasmic reticulum-mitochondria contact sites (ERM-CS), found from yeast to mammals, are interface structures where membranes of the two organelles are maintained in close proximity by tethering protein complexes. These structures play a prominent role in the communication between the two organelles, including the transport of molecules and transmission of regulatory signals, and have been implicated in apoptotic signaling, though the exact mechanism is still unclear. In the present work we questioned if perturbation of ERM-CS could have a role in Saccharomyces cerevisiae acetic acidinduced apoptosis. We also aimed to assess if perturbation of mitochondrial phospholipid content resulting from deficiency in ERM-CS components or in proteins involved in phospholipid synthesis or transport could influence acetic acid-induced apoptosis. Cell viability assays and assessment of cytochrome c (cyt c) release carried in S. cerevisiae and in mutants affected in the above mentioned processes show that all the mutant strains, except those involved in cardiolipin biosynthesis and remodeling, display a delay in apoptotic cell death in response to acetic acid treatment related with an hindrance of cyt c release. Analysis of the phospholipid composition of mitochondria isolated from the strains under study, grown in glucose or in a less repressive carbon source, and treated or not with acetic acid, show different profiles between carbon sources and the different strains, and also after treatment with acetic acid. Knowing the important role of the ERMES complex in the mitochondrial metabolism, and to uncover if this complex could be involved in Bax mediated cell death, we transformed mutant strains deficient in each protein of this complex with Bax. Assessment of cell death induced by expression of Bax, suggested that there is no alteration in any of the transformed strains in comparison with the BY4741 phenotype, with the exception of one mutant, which showed a slight decrease in cell survival. However, further analysis is necessary to confirm these results. |
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