The ability of cells to respond to physical forces is central to development and physiology, but until now it has been difficult to directly measure forces across proteins in vivo. Here, however, a calibrated biosensor is described that can measure forces with high sensitivity across specific proteins in cells. This is applied to the vinculin protein, and a regulatory mechanism is revealed in which the force applied to vinculin determines whether focal adhesions assemble or disassemble.

K+ channels can convert between conductive and non-conductive forms through mechanisms that range from flicker transitions (which occur in microseconds) to C-type inactivation (which occurs on millisecond to second timescales). Here, the mechanisms are revealed through which movements of the inner gate of the K+ channel KcsA trigger conformational changes at the selectivity filter, leading to the non-conductive C-type inactivated state.

Heidi Newberg, a physicist and astronomer at Rensselaer Polytechnic Institute in Troy, New York, has won a National Science Foundation grant to create the first partnership between a US team and a Chinese-led astronomy project.