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Bravo-Sagua 2019 MiPschool Coimbra
Has abstract [[Image:MITOEAGLE-logo.jpg|left|100px|link
[[Image:MITOEAGLE-logo.jpg|left|100px|link=http://www.mitoeagle.org/index.php/MitoEAGLE|COST Action MitoEAGLE]] Contact points between the endoplasmic reticulum (ER) and mitochondria enable Ca<sup>2+</sup> transfer between both organelles, which is a key mechanism in the modulation of mitochondrial metabolism. During early ER stress, this communication increases as an adaptive mechanism [1]. The signalling pathways controlling this response, however, are yet to be fully characterized. As candidates, we hypothesised that Caveolin-1 (CAV1) may be implicated, as it is enriched at ER–mitochondria contact sites [2]. PKA was also a candidate, as its activity has been shown to regulate organelle dynamics [3]. We used wild type HeLa cells for overexpressing CAV1. Early ER stress was induced with tunicamycin 0,5 µg/mL for 4 h. We measured ER–mitochondria contacts via electron microscopy and confocal microscopy. For Ca<sup>2+</sup> transfer, we used the fluorescent probe Rhod-FF. To evaluate mitochondrial respiration, we measured a Clark’s electrode. DRP1 phosphorylation was analysed through western blot. Cell viability was determined though annexin V staining using flow cytometry. Early ER stress augmented ER–mitochondria contacts, which was prevented by CAV1 overexpression. This rendered ER-to-mitochondria Ca<sup>2+</sup> transfer and mitochondrial bioenergetics unresponsive to ER stress. PKA inhibition with H89 or siRNA also impaired the increase in organelle contacts, Ca<sup>2+</sup> transfer and mitochondrial respiration. CAV1 overexpression reduced PKA-mediated DRP1 phosphorylation, thereby enhancing ER stress-induced cell death. Increasing ER-mitochondria contacts with a synthetic linker restored cell survival. Thus, PKA promotes the increase of ER–mitochondria contacts that occurs during ER stress. CAV1, in turn, prevents PKA-mediated phosphorylation, also impairing said remodelling. Increasing ER–mitochondria contacts is necessary for the increase in mitochondrial bioenergetics and cell adaptation to ER stress [4].
tics and cell adaptation to ER stress [4].  +
Has editor [[Plangger M]]  +
Has title [[Image:BravoSaguaR.jpg|left|90px|Roberto Bravo-Sagua]] Caveolin-1 antagonizes PKA in the remodelling of metabolism modulated by ER–mitochondria communication during early ER stress.  +
Mammal and model Human  +
MiP area Respiration  + , Genetic knockout;overexpression  +
Respiration and regulation Calcium  +
Tissue and cell HeLa  +
Was submitted in year 2019  +
Was submitted to event MiPschool Coimbra 2019 +
Was written by Bravo-Sagua R + , Parra V + , Quest AFG + , Lavandero S +
Categories Abstracts
Modification date
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12:12:34, 18 June 2019  +
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