Relevance of dopamine signals anchoring dynamin-2 to the plasma membrane during Na+,K+-ATPase endocytosis

J Biol Chem. 2002 Nov 15;277(46):44108-14. doi: 10.1074/jbc.M205173200. Epub 2002 Aug 29.

Abstract

Clathrin-dependent endocytosis of Na(+),K(+)-ATPase in response to dopamine regulates its catalytic activity in intact cells. Because fission of clathrin-coated pits requires dynamin, we examined the mechanisms by which dopamine receptor signals promote dynamin-2 recruitment and assembly at the site of Na(+),K(+)-ATPase endocytosis. Western blotting revealed that dopamine increased the association of dynamin-2 with the plasma membrane and with phosphatidylinositol 3-kinase. Dopamine inhibited Na(+),K(+)-ATPase activity in OK cells and in those overexpressing wild type dynamin-2 but not in cells expressing a dominant-negative mutant. Dephosphorylation of dynamin is important for its assembly. Dopamine increased protein phosphatase 2A activity and dephosphorylated dynamin-2. In cells expressing a dominant-negative mutant of protein phosphatase 2A, dopamine failed to dephosphorylate dynamin-2 and to reduce Na(+),K(+)-ATPase activity. Dynamin-2 is phosphorylated at Ser(848), and expression of the S848A mutant significantly blocked the inhibitory effect of dopamine. These results demonstrate a distinct signaling network originating from the dopamine receptor that regulates the state of dynamin-2 phosphorylation and that promotes its location (by interaction with phosphatidylinositol 3-kinase) at the site of Na(+),K(+)-ATPase endocytosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Line
  • Cell Membrane / metabolism*
  • Cells, Cultured
  • Clathrin / metabolism
  • Dopamine / metabolism*
  • Dynamin II / metabolism*
  • Dynamins / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Endocytosis
  • Green Fluorescent Proteins
  • Kinetics
  • Luminescent Proteins / metabolism
  • Microscopy, Confocal
  • Models, Biological
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation
  • Plasmids / metabolism
  • Precipitin Tests
  • Protein Binding
  • Rats
  • Sodium-Potassium-Exchanging ATPase / metabolism*
  • Time Factors
  • Transfection

Substances

  • Clathrin
  • Luminescent Proteins
  • Green Fluorescent Proteins
  • Dynamin II
  • Dynamins
  • Sodium-Potassium-Exchanging ATPase
  • Dopamine