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bioRxiv · 10.1101/545368

Metabolic Energy Sensing by Mammalian CLC Anion/Proton Exchangers

Grieschat, M.·Langschwager, K.·Guzman, R. E.·Fahlke, C.·Alekov, A. K.
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Abstract

Mammalian CLC anion/proton exchangers control the pH and [Cl-] of the endolysosomal system, one of the major cellular nutrient uptake pathways. We explored the regulation of the vesicular transporters ClC-3, ClC-4, and ClC-5 by the adenylic system components ATP, ADP, and AMP. Using heterologous expression and whole-cell electrophysiology, we demonstrated that cytosolic ATP and ADP but not AMP and Mg2+-free ADP enhance CLC ion transport via binding to the protein C-terminal CBS domains. Biophysical investigations revealed that the effects depend on the delivery of intracellular protons into the CLC transport machinery and result from modified voltage-dependence and altered probability that CLC proteins undergo silent non-transporting cycles. Our findings demonstrate that the CLC CBS domains are able to serve as energy sensors by detecting changes in the cytosolic ATP/ADP/AMP equilibrium. The adenine nucleotide regulation of vesicular Cl-/H+ exchange creates a link between the activity of the endolysosomal system and the cellular metabolic state.

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Grieschat, M., Langschwager, K., Guzman, R. E., Fahlke, C., Alekov, A. K.. 2019-02-08. Metabolic Energy Sensing by Mammalian CLC Anion/Proton Exchangers. https://doi.org/10.1101/545368

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