Intracellular pressure controls the propagation of tension in crumpled cell membranes.

Propagation of membrane tension mediates mechanical signal transduction along surfaces of live cells and sets the time scale of mechanical equilibration of cell membranes. Recent studies in several cell types and under different conditions revealed a strikingly wide variation range of the tension propagation speeds including extremely low ones. The latter suggests a possibility of long-living inhomogeneities of membrane tension crucially affecting mechano-sensitive membrane processes.

Frontiers in Multiscale Modeling of Photoreceptor Proteins.

This perspective article highlights the challenges in the theoretical description of photoreceptor proteins using multiscale modeling, as discussed at the CECAM workshop in Tel Aviv, Israel. The participants have identified grand challenges and discussed the development of new tools to address them. Recent progress in understanding representative proteins such as green fluorescent protein, photoactive yellow protein, phytochrome, and rhodopsin is presented, along with methodological developments.

The interplay between chromophore and protein determines the extended excited state dynamics in a single-domain phytochrome.

Phytochromes are a diverse family of bilin-binding photoreceptors that regulate a wide range of physiological processes. Their photochemical properties make them attractive for applications in optogenetics and superresolution microscopy. Phytochromes undergo reversible photoconversion triggered by the ⇄ photoisomerization about the double bond in the bilin chromophore.

TMAO mediates effective attraction between lipid membranes by partitioning unevenly between bulk and lipid domains.

Under environmental duress, many organisms accumulate large amounts of osmolytes - molecularly small organic solutes. Osmolytes are known to counteract stress, driving proteins to their compact native states by their exclusion from protein surfaces. In contrast, the effect of osmolytes on lipid membranes is poorly understood and widely debated.