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bioRxiv · 10.1101/2020.01.02.893073

Endomembrane Cation Chloride Cotransporters (CCC1s) modulate endo- and exocytosis

Wege, S.·McKay, D. W.·Qu, Y.·McFarlane, H. E.·Situmorang, A.·Gilliham, M.
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Abstract

Plant cells maintain a low luminal pH in the Trans-Golgi-Network/Early Endosome (TGN/EE), the organelle in which the secretory and endocytic pathways intersect. Impaired TGN/EE pH regulation translates into severe plant growth defects. The identity of the proton pump and proton/ion antiporters that regulate TGN/EE pH have been determined, but an essential component required to complete the TGN/EE membrane transport circuit remains unidentified - a pathway for cation and anion efflux. Here, we have used complementation, genetically encoded fluorescent sensors, and pharmacological treatments to demonstrate that the TGN/EE localised Arabidopsis Cation Chloride Cotransporter (CCC1) is this missing component necessary for regulating TGN/EE pH and function. Loss of CCC1 function leads to alterations in TGN/EE-mediated processes including endo- and exocytosis, and trafficking to the vacuole, and response to abiotic stress, consistent with the multitude of phenotypes observed in ccc1 knockout plants. This discovery places CCC1 as a central component of plant cellular function.

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Wege, S., McKay, D. W., Qu, Y., McFarlane, H. E., Situmorang, A., Gilliham, M.. 2020-01-02. Endomembrane Cation Chloride Cotransporters (CCC1s) modulate endo- and exocytosis. https://doi.org/10.1101/2020.01.02.893073

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