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Joensuu M, Padmanabhan P, Durisic N, Bademosi ATD, Cooper-Williams E, Morrow IC, Harper CB, Jung W, Parton RG, Goodhill GJ, Papadopulos A, Meunier FA. Subdiffractional tracking of internalized molecules reveals heterogeneous motion states of synaptic vesicles. J Cell Biol 2016; 215:277-292. [PMID: 27810917 PMCID: PMC5080683 DOI: 10.1083/jcb.201604001] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 09/30/2016] [Indexed: 11/23/2022] Open
Abstract
Joensuu et al. describe a tool for subdiffractional tracking of internalized molecules. They reveal that synaptic vesicles exhibit stochastic switching between heterogeneous diffusive and transport states in live hippocampal nerve terminals. Our understanding of endocytic pathway dynamics is severely restricted by the diffraction limit of light microscopy. To address this, we implemented a novel technique based on the subdiffractional tracking of internalized molecules (sdTIM). This allowed us to image anti–green fluorescent protein Atto647N-tagged nanobodies trapped in synaptic vesicles (SVs) from live hippocampal nerve terminals expressing vesicle-associated membrane protein 2 (VAMP2)–pHluorin with 36-nm localization precision. Our results showed that, once internalized, VAMP2–pHluorin/Atto647N–tagged nanobodies exhibited a markedly lower mobility than on the plasma membrane, an effect that was reversed upon restimulation in presynapses but not in neighboring axons. Using Bayesian model selection applied to hidden Markov modeling, we found that SVs oscillated between diffusive states or a combination of diffusive and transport states with opposite directionality. Importantly, SVs exhibiting diffusive motion were relatively less likely to switch to the transport motion. These results highlight the potential of the sdTIM technique to provide new insights into the dynamics of endocytic pathways in a wide variety of cellular settings.
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Affiliation(s)
- Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Pranesh Padmanabhan
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Nela Durisic
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Adekunle T D Bademosi
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | | | - Isabel C Morrow
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Callista B Harper
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - WooRam Jung
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.,Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.,Centre for Microscopy and Microanalysis, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Geoffrey J Goodhill
- Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia.,School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andreas Papadopulos
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia .,Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland 4072, Australia .,Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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