LETM proteins play a role in the accumulation of mitochondrially encoded proteins in Arabidopsis thaliana and AtLETM2 displays parent of origin effects

Research output: Contribution to journalArticle

Abstract

The Arabidopsis thaliana genome contains two genes with homology to the mitochondrial protein LETM1 (leucine zipper-EF-hand-containing transmembrane protein). Inactivation of both genes, Atletm1 and Atletm2, together is lethal. Plants that are hemizygous for AtLETM2 and homozygous for Atletm1 (letm1(-/-) LETM2(+/-)) displayed a mild retarded growth phenotype during early seedling growth. It was shown that accumulation of mitochondrial proteins was reduced in hemizygous (letm1(-/-) LETM2(+/-)) plants. Examination of respiratory chain proteins by Western blotting, blue native PAGE, and enzymatic activity assays revealed that the steady state level of ATP synthase was reduced in abundance, whereas the steady state levels of other respiratory chain proteins remained unchanged. The absence of a functional maternal AtLETM2 allele in an Atletm1 mutant background resulted in early seed abortion. Reciprocal crosses revealed that maternally, but not paternally, derived AtLETM2 was absolutely required for seed development. This requirement for a functional maternal allele of AtLETM2 was confirmed using direct sequencing of reciprocal crosses of Col-0 and Ler accessions. Furthermore, AtLETM2 promoter β-glucuronidase constructs displayed exclusive maternal expression patterns.

Details

Authors
  • Botao Zhang
  • Chris Carrie
  • Aneta Ivanova
  • Reena Narsai
  • Monika W Murcha
  • Owen Duncan
  • Yan Wang
  • Simon R Law
  • Verónica Albrecht
  • Barry James Pogson
  • Estelle Giraud
  • Olivier Van Aken
  • James Whelan
External organisations
  • Australian Research Council Centre of Excellence in Plant Energy Biology
  • Australian National University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Botany
  • Biochemistry and Molecular Biology

Keywords

  • Arabidopsis, Arabidopsis Proteins, Electron Transport, Gene Expression Regulation, Plant, Mitochondria, Mitochondrial Proteins
Original languageEnglish
Pages (from-to)41757-73
Number of pages17
JournalJournal of Biological Chemistry
Volume287
Issue number50
Publication statusPublished - 2012 Dec 7
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes