AFM/TIRF force clamp measurements of neurosecretory vesicle tethers reveal characteristic unfolding steps.

ABSTRACT: Although several proteins have been implicated in secretory vesicle tethering, the identity and mechanical properties of the components forming the physical vesicle-plasma membrane link remain unknown. Here we present the first experimental measurements of nanomechanical properties of secretory vesicle-plasma membrane tethers using combined AFM force clamp and TIRF microscopy on membrane sheets from PC12 cells expressing the vesicle marker ANF-eGFP. Application of pulling forces generated tether extensions composed of multiple steps with variable length. The frequency of short (<10 nm) tether extension events was markedly higher when a fluorescent vesicle was present at the cantilever tip and increased in the presence of GTPγS, indicating that these events reflect specifically the properti

SUBMITTER: Harris MC 

PROVIDER: S-EPMC5360256 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature