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The mitochondrial Ras-related GTPase Miro: views from inside and outside the metazoan kingdom

Shohei Yamaoka1, Ikuko Hara-Nishimura2

  • 1Graduate School of Biostudies, Kyoto University Kyoto, Japan.

Frontiers in Plant Science
|August 1, 2014
PubMed

Insights

Miro GTPase is vital for mitochondrial transport in animals but maintains mitochondrial shape in other eukaryotes. Its transport role likely evolved in animals after diverging from other life forms.

Area of Science:

  • Mitochondrial biology
  • Cellular transport mechanisms
  • Evolutionary biology

Background:

  • Miro GTPase, a Ras superfamily member, anchors to the mitochondrial outer membrane.
  • Miro possesses GTPase domains, EF hand motifs, and a transmembrane domain.
  • Previous studies highlight Miro's role in calcium-dependent mitochondrial transport in metazoans.

Purpose of the Study:

  • To investigate the conserved and divergent functions of Miro GTPase across eukaryotic lineages.
  • To explore the evolutionary origins of Miro's role in mitochondrial transport.

Main Methods:

  • Comparative analysis of Miro GTPase structure and function across diverse eukaryotes (metazoans, yeasts, plants).
  • Review of existing literature on Miro's involvement in mitochondrial morphology, homeostasis, and transport.

Main Results:

  • In non-metazoans (yeasts, plants), Miro primarily maintains mitochondrial morphology and homeostasis.
  • In metazoans (mammals, fruit flies), Miro regulates calcium-dependent mitochondrial transport along microtubules.
  • Miro GTPase is highly conserved across eukaryotes, suggesting a common ancestral mitochondrial function.

Conclusions:

  • Miro GTPase likely possesses a conserved ancestral function in mitochondria.
  • The regulation of mitochondrial transport by Miro appears to be a metazoan-specific innovation.
  • Evolutionary divergence led to specialized roles for Miro in different eukaryotic lineages.
Keywords:
Arabidopsis thalianaDictyostelium discoideumMiroRas GTPaseSaccharomyces cerevisiaemetazoanmitochondria

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