Format

Send to

Choose Destination
Plant J. 2011 Sep;67(6):1067-80. doi: 10.1111/j.1365-313X.2011.04658.x. Epub 2011 Jul 6.

The RCC1 family protein RUG3 is required for splicing of nad2 and complex I biogenesis in mitochondria of Arabidopsis thaliana.

Author information

1
Australian Research Council Centre of Excellence in Plant Energy Biology, M316, University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Australia. kristina.kuehn@ibmp-cnrs.unistra.fr

Abstract

We have identified a mitochondrial protein (RUG3) that is required for accumulation of mitochondrial respiratory chain complex I. RUG3 is related to human REGULATOR OF CHROMOSOME CONDENSATION 1 (RCC1) and Arabidopsis UV-B RESISTANCE 8 (UVR8). Although the family of RCC1-like proteins in Arabidopsis has over 20 members, UVR8 is the sole plant representative of this family to have been functionally characterized. Mitochondria from Arabidopsis plants lacking a functional RUG3 gene showed greatly reduced complex I abundance and activity. In contrast, accumulation of complexes III, IV and V of the oxidative phosphorylation system and the capacity for succinate-dependent respiration were unaffected. A comprehensive study of processes contributing to complex I biogenesis in rug3 mutants revealed that RUG3 is required for efficient splicing of the nad2 mRNA, which encodes a complex I subunit. A comparison of the formation of complex I assembly intermediates between rug3 and wild type mitochondria indicated that NAD2 enters the assembly pathway at an early stage. Remarkably, rug3 mutants displayed increased capacities for import of nucleus-encoded mitochondrial proteins into the organelle and showed moderately increased mitochondrial transcript levels. This observation is consistent with global transcript changes indicating enhanced mitochondrial biogenesis in the rug3 mutant in response to the complex I defect.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center