Oliver Beckstein

Abstract Endosome maturation requires lumen acidification. Is progressive lumen acidification sensed by cytosolic-side molecules driving maturation? We show here that proton efflux through the endosomal Na⁺/H⁺ Exchanger (NHE6) activates the late endosome master regulator Rab7. Importantly, NHE6 is mutated in the childhood neurologic disorder Christianson Syndrome. We demonstrate that NHE6 interacts with the Rab7 GTPase-activating protein (GAP) TBC1D5 in a complex with Rab7 on the late endosome.

Abstract Molecular Dynamics (MD) simulations are a versatile tool to investigate the interactions of proteins within their environments, in particular of membrane proteins with the surrounding lipids. However, quantitative analysis of lipid-protein binding kinetics has remained challenging due to considerable noise and low frequency of long binding events, even in hundreds of microseconds of simulation data.