Calcium diffusion and mechanosensing
The first part of my project aims at collecting as much as possible (AKA "all") the current knowledge of the mechanosensing mechanism, or WHY and HOW the super-relaxed myosin heads decide to rise up and start the actomyosin cycle to produce force. Here, I report a striking result from Brunello and Fusi, at King's College of London, published in PNAS in march 2020. The applied the X-ray diffraction technique to study the thick filament structure in cardiac muscle. Small angle XRay diffraction is one of the most used techniques to dynamically analyze the state of the thick filament, thanks to the different spacing that the myosin motors have in each state. The interpretation of the data is made through mathematical models of predicted X-ray diffractions from different populations. Despite it is necessarily based on some assumptions, its interpretation can be considered well established in the literature. I do not report here the beautiful pictures reported in the paper b