In a study led by the team of Anne-Marie Duchêne at IBMP, in collaboration with several partners, a key mechanism coordinating protein synthesis and mitochondrial function in plants has been uncovered. Published in PNAS, this work addresses a fundamental question in cell biology: how cells ensure the efficient production and targeting of proteins required for mitochondrial activity. Although mitochondria play a central role in cellular energy metabolism, most of their proteins are encoded in the nucleus, requiring tight coordination between gene expression, translation and protein import.
The researchers demonstrate that the protein FMT (FRIENDLY) plays a central role in this coordination by organizing the localization of mRNAs encoding mitochondrial proteins in close proximity to mitochondria. This spatial arrangement enables localized translation, thereby optimizing the efficiency of protein synthesis and delivery. The study further shows that FMT interacts with components of the translation machinery, including ribosomes, and contributes to the formation of specialized translation sites within the cell. In the absence of FMT, this spatial organization is disrupted, leading to mislocalization of mRNAs and impaired mitochondrial function. These findings highlight a fundamental principle of cell organization: protein synthesis is not uniformly distributed throughout the cytoplasm but is spatially regulated. Such compartmentalization allows cells to rapidly adjust protein production to metabolic demands and ensures efficient mitochondrial activity. By revealing this central role of FMT, this work led by the team of Anne-Marie Duchêne provides new insights into post-transcriptional regulation and the spatial organization of cellular processes in plants.
These results open new perspectives for understanding how plants adapt their metabolism to environmental conditions, particularly under stress, where mitochondrial function plays a crucial role.
