Dephosphorylation by calcineurin regulates translocation of Drp1 to mitochondria

Proc Natl Acad Sci U S A. 2008 Oct 14;105(41):15803-8. doi: 10.1073/pnas.0808249105. Epub 2008 Oct 6.

Abstract

Changes in mitochondrial morphology that occur during cell cycle, differentiation, and death are tightly regulated by the balance between fusion and fission processes. Excessive fragmentation can be caused by inhibition of the fusion machinery and is a common consequence of dysfunction of the organelle. Here, we show a role for calcineurin-dependent translocation of the profission dynamin related protein 1 (Drp1) to mitochondria in dysfunction-induced fragmentation. When mitochondrial depolarization is associated with sustained cytosolic Ca(2+) rise, it activates the cytosolic phosphatase calcineurin that normally interacts with Drp1. Calcineurin-dependent dephosphorylation of Drp1, and in particular of its conserved serine 637, regulates its translocation to mitochondria as substantiated by site directed mutagenesis. Thus, fragmentation of depolarized mitochondria depends on a loop involving sustained Ca(2+) rise, activation of calcineurin, and dephosphorylation of Drp1 and its translocation to the organelle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcineurin / metabolism*
  • Calcineurin / physiology
  • Calcium
  • Dynamins
  • GTP Phosphohydrolases / metabolism*
  • HeLa Cells
  • Humans
  • Membrane Potential, Mitochondrial
  • Microtubule-Associated Proteins / metabolism*
  • Mitochondria / metabolism*
  • Mitochondrial Proteins / metabolism*
  • Mutagenesis, Site-Directed
  • Phosphorylation
  • Protein Transport*
  • Serine

Substances

  • Microtubule-Associated Proteins
  • Mitochondrial Proteins
  • Serine
  • Calcineurin
  • GTP Phosphohydrolases
  • DNM1L protein, human
  • Dynamins
  • Calcium