Mitochondrial uncouplers inhibit clathrin-mediated endocytosis largely through cytoplasmic acidification

Nat Commun. 2016 Jun 8;7:11710. doi: 10.1038/ncomms11710.

Abstract

ATP production requires the establishment of an electrochemical proton gradient across the inner mitochondrial membrane. Mitochondrial uncouplers dissipate this proton gradient and disrupt numerous cellular processes, including vesicular trafficking, mainly through energy depletion. Here we show that Endosidin9 (ES9), a novel mitochondrial uncoupler, is a potent inhibitor of clathrin-mediated endocytosis (CME) in different systems and that ES9 induces inhibition of CME not because of its effect on cellular ATP, but rather due to its protonophore activity that leads to cytoplasm acidification. We show that the known tyrosine kinase inhibitor tyrphostinA23, which is routinely used to block CME, displays similar properties, thus questioning its use as a specific inhibitor of cargo recognition by the AP-2 adaptor complex via tyrosine motif-based endocytosis signals. Furthermore, we show that cytoplasm acidification dramatically affects the dynamics and recruitment of clathrin and associated adaptors, and leads to reduction of phosphatidylinositol 4,5-biphosphate from the plasma membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acids / metabolism*
  • Adenosine Triphosphate / deficiency
  • Adenosine Triphosphate / metabolism
  • Arabidopsis / drug effects
  • Arabidopsis / metabolism
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Clathrin / metabolism*
  • Endocytosis / drug effects*
  • Energy Metabolism / drug effects
  • HeLa Cells
  • Humans
  • Mitochondria / drug effects
  • Mitochondria / metabolism*
  • Organelles / drug effects
  • Organelles / metabolism
  • Protein Transport / drug effects
  • Quinolones / chemistry
  • Quinolones / pharmacology
  • Uncoupling Agents / pharmacology*

Substances

  • Acids
  • Clathrin
  • Quinolones
  • Uncoupling Agents
  • Adenosine Triphosphate