Single Molecule Approach for Cell Biology

Abstract

Tools capable of imaging and perturbing mechanical signaling pathways with fine spatiotemporal resolution have been elusive despite their importance in diverse cellular processes. The challenge in developing a mechanogenetic (i.e. genetically encoded mechanical perturbations) toolkit stems from the fact that many mechanically-activated processes are localized in space and time, yet additionally require quantitative mechanical loading to become activated. To address this unmet need, we synthesized magnetoplasmonic nanoparticles that can image, localize, and mechanically load targeted proteins with high spatiotemporal resolution. We demonstrate their utility as a quantitative perturbation system by investigating the cell surface activation of Notch and E-cadherin receptors. By measuring cellular responses to various spatial, chemical, temporal, and mechanical inputs at the single molecule and single cell level, we reveal how spatial segregation and mechanical force cooperate to direct receptor activation dynamics. This generalizable technique can be used to control and understand diverse mechanosensitive processes in cell signalling.