Frataxin Is Localized to Both the Chloroplast and Mitochondrion and Is Involved in Chloroplast Fe-S Protein Function in Arabidopsis

PLoS One. 2015 Oct 30;10(10):e0141443. doi: 10.1371/journal.pone.0141443. eCollection 2015.

Abstract

Frataxin plays a key role in eukaryotic cellular iron metabolism, particularly in mitochondrial heme and iron-sulfur (Fe-S) cluster biosynthesis. However, its precise role has yet to be elucidated. In this work, we studied the subcellular localization of Arabidopsis frataxin, AtFH, using confocal microscopy, and found a novel dual localization for this protein. We demonstrate that plant frataxin is targeted to both the mitochondria and the chloroplast, where it may play a role in Fe-S cluster metabolism as suggested by functional studies on nitrite reductase (NIR) and ferredoxin (Fd), two Fe-S containing chloroplast proteins, in AtFH deficient plants. Our results indicate that frataxin deficiency alters the normal functioning of chloroplasts by affecting the levels of Fe, chlorophyll, and the photosynthetic electron transport chain in this organelle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis / ultrastructure
  • Arabidopsis Proteins / analysis
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Arabidopsis Proteins / physiology*
  • Chlorophyll / analysis
  • Chloroplasts / chemistry
  • Chloroplasts / metabolism*
  • Ferredoxins / genetics
  • Ferredoxins / metabolism
  • Gene Deletion
  • Iron-Binding Proteins / analysis
  • Iron-Binding Proteins / genetics
  • Iron-Binding Proteins / physiology*
  • Iron-Sulfur Proteins / metabolism*
  • Microscopy, Confocal
  • Mitochondria / chemistry
  • Mitochondria / metabolism*
  • Mitochondrial Proteins / physiology
  • Nitrite Reductases / genetics
  • Nitrite Reductases / metabolism
  • Plants, Genetically Modified
  • Protoplasts / metabolism
  • Protoplasts / ultrastructure
  • RNA, Messenger / genetics
  • RNA, Plant / genetics
  • Real-Time Polymerase Chain Reaction

Substances

  • Arabidopsis Proteins
  • Ferredoxins
  • Iron-Binding Proteins
  • Iron-Sulfur Proteins
  • Mitochondrial Proteins
  • RNA, Messenger
  • RNA, Plant
  • frataxin protein, Arabidopsis
  • Chlorophyll
  • NIR1 protein, Arabidopsis
  • Nitrite Reductases

Grants and funding

This work was supported by grants from ANPCyT (PICT 0512, 2188 and 2184), the PICS-CNRS Program 3641 and the Institut National de Recherche Agronomique (INRA, France). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.