Institut de Biologie StructuraleGrenoble / France


Malene Jensen, laureate of the first Impulscience® Program of the Bettencourt Schueller Fondation

Malene Jensen, CNRS research director in the “Protein Dynamics and Flexibility” group at the IBS, is one of the 7 researchers in Life Science distinguished by the first Impulscience grant program of the Bettencourt Schueller Fondation. The Foundation is committed to financially support each of these researchers for a period of 5 years and with 2.3 million euros, a sum that covers the research program, a personal bonus for the researcher and the management costs.
The work of Malene will allow to observe more closely the capacity of cells to respond continuously to internal and external signals, thanks to so-called scaffold proteins. Malene will use nuclear magnetic resonance spectroscopy to study intrinsically disordered scaffold proteins in the MAPK cell signalling pathways and she will visualise their assembly with kinases and GTPases. The work will reveal how scaffold proteins contribute to enzymatic activity and signalling specificity. The study of the specific mechanisms of cell signalling is particularly relevant because deregulation of many signalling pathways is associated with diseases, such as metabolic disorders and cancer. The work will therefore open new avenues for drug discovery by targeting the recruitment of enzymes to scaffold proteins.

New issue for the IBS Newsletter

Find the June 2022 issue (in french only).

Fluorescent proteins don’t like sunburns !

Super resolution microscopy continues to reveal new insights into biology at the nanoscale. Quantitative measurements using super resolution microscopy, however, remain limited due to the highly complex photophysical behavior of the used fluorescent labels. In the case of green-to-red photoconvertible fluorescent proteins (PCFPs), their limited green-to-red conversion efficiency lowers the achievable spatial resolution and causes undercounting errors in quantitative experiments. Researchers of the PIXEL team have shown that the photoconversion efficiency of several popular PCFPs, including mEos4b, Dendra2 and pcStar, strongly depends on the applied illumination conditions. In particular, they revealed that the photoconversion efficiency depends in a non-linear manner on the used 405-nm light intensity, due to a non-linear photobleaching mechanism. Their findings contribute to our understanding of FP photophysics and inform the design of optimized illumination schemes for photoactivated localization microscopy.

mEos4b Photoconversion Efficiency Depends on Laser Illumination Conditions Used in PALM. Wulffele J, Thédié D, Glushonkov O, Bourgeois D. J. Phys. Chem. Lett. 13:5075–5080.

Contact : Dominique Bourgeois (IBS/Integrated Imaging of Stress Response Group)