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Ribeye protein is intrinsically dynamic but is stabilized in the context of the ribbon synapse
Author(s) -
Chen Zongwei,
Chou ShihWei,
McDermott Brian M.
Publication year - 2018
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jp271215
Subject(s) - ribbon synapse , hair cell , fluorescence recovery after photobleaching , context (archaeology) , ribbon , lateral line , biophysics , mcherry , zebrafish , photobleaching , microbiology and biotechnology , biology , inner ear , green fluorescent protein , synaptic vesicle , vesicle , chemistry , anatomy , fluorescence , materials science , biochemistry , membrane , optics , paleontology , gene , composite material , physics
Key points The synaptic ribbon is an organelle that coordinates rapid and sustained vesicle release to enable hearing and balance. Ribeye a and b proteins are major constituents of the synaptic ribbon in hair cells. In this study, we use optically clear transgenic zebrafish to examine the potential dynamics of ribeye proteins in vivo . We demonstrate that ribeye proteins are inherently dynamic but are stabilized at the ribbons of hair cells in the ear and the lateral line system.Abstract Ribeye protein is a major constituent of the synaptic ribbon, an organelle that coordinates rapid and sustained vesicle release to enable hearing and balance. The ribbon is considered to be a stable structure. However, under certain physiological conditions such as acoustic overexposure that results in temporary noise‐induced hearing loss or perturbations of ion channels, ribbons may change shape or vanish altogether, suggesting greater plasticity than previously appreciated. The dynamic properties of ribeye proteins are unknown. Here we use transgenesis and imaging to explore the behaviours of ribeye proteins within the ribbon and also their intrinsic properties outside the context of the ribbon synapse in a control cell type, the skin cell. By fluorescence recovery after photobleaching (FRAP) on transgenic zebrafish larvae, we test whether ribeye proteins are dynamic in vivo in real time. In the skin, a cell type devoid of synaptic contacts, Ribeye a‐mCherry exchanges with ribbon‐like structures on a time scale of minutes ( t 1/2 = 3.2 min). In contrast, Ribeye a of the ear and lateral line and Ribeye b of the lateral line each exchange at ribbons of hair cells an order of magnitude slower ( t 1/2 of 125.6 min, 107.0 min and 95.3 min, respectively) than Ribeye a of the skin. These basal exchange rates suggest that long‐term ribbon presence may require ribeye renewal. Our studies demonstrate that ribeye proteins are inherently dynamic but are stabilized at the ribbons of sensory cells in vivo .