Metabolism and trafficking of RNA within the plant cell

Group leader : Laurence MARECHAL-DROUARD

Research area

Defined as the powerhouse of the cell, the mitochondrion is also involved in many other vital biological processes. All these processes require an important communication between the mitochondrion and the other cellular compartments. Furthermore, the biogenesis of this organelle is complex and implies the coordinated expression of the nuclear and mitochondrial genomes as the latter one only codes for a limited set of genes.

In this context, studies concerning the metabolism of RNAs and the trafficking of RNAs between mitochondria and the other cellular compartments represent a rapidly growing and still very widely underestimated domain. Presently our main objectives are to deepen our knowledge by answering the following biological questions:

  • What are the ways of tRNA cleavage in the plant cell and which are the roles played by the small non coding RNAs generated by these cleavages?
  • What is the importance of the mRNA targeting process at the surface of mitochondria and how is the translation of mRNAs associated with organelles organized and regulated within the plant cell?
  • What are the cis and trans elements implicated in mitochondrial translation?

This work is done under the framework of the Laboratory of Excellence (LabEx) MitoCross.

Projects

  • Small non coding RNAS deriving from tRNAs (Laurence MARÉCHAL-DROUARD)
  • Targeting of mRNAs at the surface of mitochondria (Anne-Marie DUCHÊNE)
  • Mitochondrial translation in the green alga Chlamydomonas reinhardtii (Laurence MARÉCHAL-DROUARD)

Projects

Small non coding RNAS deriving from tRNAs

Project manager: Laurence MARÉCHAL-DROUARD

Beyond their key role in translation, tRNAs play other important functions. Among them, small non-coding RNAs deriving from tRNA cleavage called tRFs (for tRNA Fragments) play major roles in various biological processes such as inhibition of translation, RNA degradation or regulation of gene expression via the silencing pathway. In the laboratory, our work aims to decipher the biogenesis and the function of plant tRFs.

Targeting of mRNAs at the surface of mitochondria

Project manager: Anne-Marie DUCHÊNE

Intracellular targeting of mRNAs and localized protein synthesis are fundamental mechanisms to control protein localization. Indeed, perturbations of mRNA targeting and localized translation have dramatic consequences in the cells. In this context our present objective is to characterize the translation platform associated with plant mitochondria and to explore the functions and regulations of mRNA targeting and translation on mitochondria.

Mitochondrial translation in the green alga Chlamydomonas reinhardtii

Project manager: Laurence MARÉCHAL-DROUARD

The mitochondrial translation process is still largely unknown in higher plants or in mammals. The main reason for this is the impossibility to transform the mitochondrial genomes of these organisms. In contrast, mitochondrial transformation is possible in Chlamydomonas reinhardtii. Thus, we choose this photosynthetic organism to elucidate the molecular mechanisms involved in the protein synthesis of the mitochondrial mRNAs.

Members

Selected Publications

  • COGNAT V., MORELLE G, MEGEL C, LALANDE S., MOLINIER J., VINCENT T., SMALL I, DUCHÊNE A. and MARÉCHAL-DROUARD L.

    The nuclear and organellar tRNA-derived RNA fragment population in Arabidopsis thaliana is hygly dynamic

    Nucleic Acids Research, 45:3460-3472, 2016. | PMI27899576 :

  • MICHAUD M., UBRIG E., FILLEUR S., ERHARDT M., EPHRITIKHINE G., MARÉCHAL-DROUARD L. and DUCHÊNE A.

    Differential targeting of VDAC3 mRNA isoforms influences mitochondria morphology

    Proceedings of the National Academy of Sciences U S A, 111(24):8991-8996, 2014. | PMI24889622 :

  • SALINAS-GIEGÉ T., EL FAROUK-AMEQRANE S., UBRIG E., SAUTER C., DUCHÊNE A. and MARÉCHAL-DROUARD L.

    Molecular basis for the differential interaction of plant mitochondrial VDAC proteins with tRNAs

    Nucleic Acids Research, 42(15):9937-48, 2014. | PMI25114051 :

  • COGNAT V., PAWLAK G., DUCHÊNE A., DAUJAT M., GIGANT A., SALINAS-GIEGÉ T., MICHAUD M., GUTMANN B., GIEGÉ P., GOBERT A. and MARÉCHAL-DROUARD L.

    PlantRNA, a database for tRNAs of photosynthetic eukaryotes.

    Nucleic Acids Research, 41:273-279, 2013. | PMI23066098 :

  • SALINAS-GIEGÉ T., DUBY F., LAROSA V., COOSEMANS N., BONNEFOY N., MOTTE P., MARÉCHAL-DROUARD L. and REMACLE C.

    Co-evolution of mitochondrial tRNA import and codon usage determines translational efficiency in the green alga chlamydomonas

    PLoS Genetics, 8(9):e1002946, 2012. | PMI23028354 :

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