The Na+/K+-ATPase and the amyloid-beta peptide aβ1-40 control the cellular distribution, abundance and activity of TRPC6 channels.
The Na(+)/K(+)-ATPase interacts with the non-selective cation channels TRPC6 but the functional consequences of this association are unknown. Experiments performed with HEK cells over-expressing TRPC6 channels showed that inhibiting the activity of the Na(+)/K(+)-ATPase with ouabain reduced the amount of TRPC6 proteins and depressed Ca(2+) entry through TRPC6. This effect, not mimicked by membrane depolarization with KCl, was abolished by sucrose and bafilomycin-A, and was partially sensitive to the intracellular Ca(2+) chelator BAPTA/AM. Biotinylation and subcellular fractionation experiments showed that ouabain caused a multifaceted redistribution of TRPC6 to the plasma membrane and to an endo/lysosomal compartment where they were degraded. The amyloid beta peptide Aβ(1-40), another inhibitor of the Na(+)/K(+)-ATPase, but not the shorter peptide Aβ1-16, reduced TRPC6 protein levels and depressed TRPC6-mediated responses. In cortical neurons from embryonic mice, ouabain, veratridine (an opener of voltage-gated Na(+) channel), and Aβ(1-40) reduced TRPC6-mediated Ca(2+) responses whereas Aβ(1-16) was ineffective. Furthermore, when Aβ(1-40) was co-added together with zinc acetate it could no longer control TRPC6 activity. Altogether, this work shows the existence of a functional coupling between the Na(+)/K(+)-ATPase and TRPC6. It also suggests that the abundance, distribution and activity of TRPC6 can be regulated by cardiotonic steroids like ouabain and the naturally occurring peptide Aβ(1-40) which underlines the pathophysiological significance of these processes.
Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France.
Sylvain
S
Chauvet
URPhyM-Laboratoire de Chimie Physiologique, University of Namur, Belgium.
Marielle
M
Boonen
Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France.
Mireille
M
Chevallet
Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France.
Louis
L
Jarvis
Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France.
Addis
A
Abebe
Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France.
Mohamed
M
Benharouga
CNRS, Laboratoire de Chimie de Coordination, Toulouse, France.
Peter
P
Faller
URPhyM-Laboratoire de Chimie Physiologique, University of Namur, Belgium.
Michel
M
Jadot
Université Grenoble Alpes, F-38000 Grenoble, France; CNRS, F-38000 Grenoble, France; CEA, iRTSV-LCBM, F-38000 Grenoble, France. Electronic address: alexandre.bouron@cea.fr.
Alexandre
A
Bouron
D016229:Amyloid beta-Peptides / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D020013:Calcium Signaling; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D010446:Peptide Fragments / Q000378:metabolism* / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects / Q000235:genetics; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism*; D050052:TRPC Cation Channels / Q000235:genetics / Q000378:metabolism*; D000074287:TRPC6 Cation Channel
D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D050052:TRPC Cation Channels; D000074287:TRPC6 Cation Channel; C117032:TRPC6 protein, human; C078592:amyloid beta-protein (1-40); D000254:Sodium-Potassium-Exchanging ATPase
Aβ peptides; Lysosomes; Na/K pump; Neurons; TRPC6; Trafficking