title: Quantitative super-resolution imaging of Bruchpilot distinguishes active zone states.
abstract: The precise molecular architecture of synaptic active zones (AZs) gives rise to different structural and functional AZ states that fundamentally shape chemical neurotransmission. However, elucidating the nanoscopic protein arrangement at AZs is impeded by the diffraction-limited resolution of conventional light microscopy. Here we introduce new approaches to quantify endogenous protein organization at single-molecule resolution in situ with super-resolution imaging by direct stochastic optical reconstruction microscopy (dSTORM). Focusing on the Drosophila neuromuscular junction (NMJ), we find that the AZ cytomatrix (CAZ) is composed of units containing ~137 Bruchpilot (Brp) proteins, three quarters of which are organized into about 15 heptameric clusters. We test for a quantitative relationship between CAZ ultrastructure and neurotransmitter release properties by engaging Drosophila mutants and electrophysiology. Our results indicate that the precise nanoscopic organization of Brp distinguishes different physiological AZ states and link functional diversification to a heretofore unrecognized neuronal gradient of the CAZ ultrastructure.
authors.affiliation: 1] Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany [2].
authors.forename: Nadine
authors.initials: N
authors.lastname: Ehmann
authors.affiliation: 1] Department of Biotechnology and Biophysics, University of Würzburg, 97074 Würzburg, Germany [2].
authors.forename: Sebastian
authors.initials: S
authors.lastname: van de Linde
authors.affiliation: Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Alon
authors.affiliation: Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany.
authors.forename: Dmitrij
authors.initials: D
authors.lastname: Ljaschenko
authors.affiliation: Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany.
authors.forename: Xi Zhen
authors.initials: XZ
authors.lastname: Keung
authors.affiliation: Department of Biotechnology and Biophysics, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Thorge
authors.initials: T
authors.lastname: Holm
authors.affiliation: 1] European Neuroscience Institute, University Medical Center Göttingen, 37077 Göttingen, Germany [2] Carl-Ludwig-Institute of Physiology, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Rings
authors.affiliation: Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: DiAntonio
authors.affiliation: 1] European Neuroscience Institute, University Medical Center Göttingen, 37077 Göttingen, Germany [2] Carl-Ludwig-Institute of Physiology, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hallermann
authors.affiliation: 1] Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel [2] Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Uri
authors.initials: U
authors.lastname: Ashery
authors.affiliation: Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Heckmann
authors.affiliation: Department of Biotechnology and Biophysics, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Sauer
authors.affiliation: Department of Neurophysiology, Institute of Physiology, University of Würzburg, 97070 Würzburg, Germany.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Kittel
mesh_terms: D000818:Animals; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D055724:Electrophysiological Phenomena / Q000502:physiology; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D009469:Neuromuscular Junction / Q000737:chemistry / Q000648:ultrastructure; D013329:Structure-Activity Relationship; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: C510146:BRP protein, Drosophila; D029721:Drosophila Proteins