The Atypical Rho GTPases Miro-1 and Miro-2 Have Essential Roles in Mitochondrial Trafficking

Biochem Biophys Res Commun. 2006 Jun 2;344(2):500-10. doi: 10.1016/j.bbrc.2006.03.163. Epub 2006 Apr 3.

Abstract

We recently described the atypical Rho GTPases Miro-1 and Miro-2. These proteins have tandem GTP-binding domains separated by a linker region with putative calcium-binding motives. In addition, the Miro GTPases have a C-terminal transmembrane domain, which confers targeting to the mitochondria. It was reported previously that a constitutively active mutant of Miro-1 induced a clustering of the mitochondria. This response can be separated into two distinct phenotypes: a formation of aggregated mitochondria and the appearance of thread-like mitochondria probably caused by defects in mitochondrial trafficking. The first GTPase domain is required for the clustering of the mitochondria, but the effect is not dependent on the EF-hands. Miro-2 only induces aggregation and not the formation of thread-like mitochondria. Moreover, we show that Miro interacts with the Kinesin-binding proteins, GRIF-1 and OIP106, suggesting that the Miro GTPases form a link between the mitochondria and the trafficking apparatus of the microtubules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • COS Cells
  • Cell Line
  • Chlorocebus aethiops
  • Humans
  • Kidney / metabolism*
  • Mitochondria / metabolism*
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / metabolism*
  • Protein Transport / physiology
  • Structure-Activity Relationship
  • rho GTP-Binding Proteins / genetics
  • rho GTP-Binding Proteins / metabolism*

Substances

  • Mitochondrial Proteins
  • RHOT1 protein, human
  • RHOT2 protein, human
  • rho GTP-Binding Proteins