The Rice Dynamin-Related Protein OsDRP1E Negatively Regulates Programmed Cell Death by Controlling the Release of Cytochrome c from Mitochondria

PLoS Pathog. 2017 Jan 12;13(1):e1006157. doi: 10.1371/journal.ppat.1006157. eCollection 2017 Jan.

Abstract

Programmed cell death (PCD) mediated by mitochondrial processes has emerged as an important mechanism for plant development and responses to abiotic and biotic stresses. However, the role of translocation of cytochrome c from the mitochondria to the cytosol during PCD remains unclear. Here, we demonstrate that the rice dynamin-related protein 1E (OsDRP1E) negatively regulates PCD by controlling mitochondrial structure and cytochrome c release. We used a map-based cloning strategy to isolate OsDRP1E from the lesion mimic mutant dj-lm and confirmed that the E409V mutation in OsDRP1E causes spontaneous cell death in rice. Pathogen inoculation showed that dj-lm significantly enhances resistance to fungal and bacterial pathogens. Functional analysis of the E409V mutation showed that the mutant protein impairs OsDRP1E self-association and formation of a higher-order complex; this in turn reduces the GTPase activity of OsDRP1E. Furthermore, confocal microscopy showed that the E409V mutation impairs localization of OsDRP1E to the mitochondria. The E409V mutation significantly affects the morphogenesis of cristae in mitochondria and causes the abnormal release of cytochrome c from mitochondria into cytoplasm. Taken together, our results demonstrate that the mitochondria-localized protein OsDRP1E functions as a negative regulator of cytochrome c release and PCD in plants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis*
  • Chromosome Mapping
  • Cytochromes c / genetics
  • Cytochromes c / metabolism*
  • Cytoplasm / metabolism
  • Cytosol / metabolism
  • Dynamins / genetics
  • Dynamins / metabolism*
  • Gene Expression
  • Genes, Reporter
  • Mitochondria / enzymology
  • Mitochondria / ultrastructure
  • Mutation
  • Oryza / genetics
  • Oryza / physiology*
  • Oryza / ultrastructure
  • Phenotype
  • Phylogeny
  • Plant Leaves / genetics
  • Plant Leaves / physiology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Recombinant Fusion Proteins
  • Two-Hybrid System Techniques

Substances

  • Plant Proteins
  • Recombinant Fusion Proteins
  • Cytochromes c
  • Dynamins

Grants and funding

This work was funded by a grant from the National Natural Science Foundation of China to BD (31371928). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.