In-cell NMR in S. cerevisiae is a novel way of looking at disordered proteins in a crowded cellular environment. The methodology has been developed here, which could be broadly applicable to other protein systems. In an example, the non-specific interactions of the FG Nup construct, FSFG-K, with the cytoplasm is similar to previously found bacterial interactions using NMR relaxation techniques. This work was recently published in Biophysical Journal.
Torque due to crosslinkers can promote or oppose antiparallel alignment of the MTs, because the magnitude and direction of the torque depends on MT length and the crossing angle. By using the Langevin equations for translational and rotational motion of filaments we can derive a system of integro-differential equations for the length and angle between microtubule bundles.
Betterton group 2018
Members of the Biophysics group went to the mountains for hiking and the group research retreat.
Bipolar mitotic spindles form from a monopolar initial condition in a fundamental construction problem. Microtubules, motors, and cross-linkers are important for bipolarity, but the mechanisms necessary and sufficient for spindle assembly remain unknown. We developed a physical model that exhibits de novo bipolar spindle formation that agrees quantitatively with our experiments in fission yeast, thereby establishing a minimal system with which to interrogate collective self-assembly. This work was published in Science Advances.
In many biological systems, such as proteins in the nuclear pore complex, proteins in cells, and membrane proteins and lipids in the presence of lipid domains, particles diffuse in a crowded environment. Crowding can cause a particle's diffusion to be anomalous, leading to a mean squared displacement that is not linear in time. We studied a model of the dynamics of tracer particles which can bind to soft obstacles, and contrasted sticky (no bound motion) and slippery (motion while bound) obstacles.