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Guenole, A.

Publications and source records attributed to Guenole, A..

2 recordsLinked to original sources

Super-resolved live-cell imaging using Random Illumination Microscopy

Super-resolution fluorescence microscopy has been instrumental to progress in biology. Yet, the photo-induced toxicity, the loss of resolution into scattering samples or the complexity of the experimental setups curtail its general use for functional cell imaging. Here, we describe a new technology for tissue imaging reaching a 114nm/8Hz resolution at 30 {micro}m depth. Random Illumination Microscopy (RIM) consists in shining the sample with uncontrolled speckles and extracting a high-fidelity super-resolved image from the variance of the data using a reconstruction scheme accounting for the spatial correlation of the illuminations. Super-resolution unaffected by optical aberrations, undetectable phototoxicity, fast image acquisition rate and ease of use, altogether, make RIM ideally suited for functional live cell imaging in situ. RIM ability to image molecular and cellular processes in three dimensions and at high resolution is demonstrated in a wide range of biological situations such as the motion of Myosin II minifilaments in Drosophila.

bioengineering

RNF219 regulates CCR4-NOT function in mRNA translation and deadenylation

Post-transcriptional regulatory mechanisms play a role in many biological contexts through the control of mRNA degradation, translation and localization. Here, we show that the uncharacterized RING finger protein RNF219 co-purifies and strongly associates with the CCR4-NOT complex, the major mRNA deadenylase in eukaryotes, that mediates translational repression in a deadenylase activity-dependent and -independent manner. Strikingly, although RNF219, inhibits the deadenylase activity of CCR4-NOT, it enhances its capacity to repress translation of a targeted mRNA, an effect of RNF219 that requires its interaction with CCR4-NOT. We propose that RNF219 is an interacting partner of the CCR4-NOT complex that switches the translational repressive activity of CCR4-NOT from a deadenylation-dependent to a deadenylation-independent mechanism.

molecular biology