Mitochondrial volume fraction controls translation of nuclear-encoded mitochondrial proteins

https://www.biorxiv.org/content/biorxiv/early/2019/01/25/529289.full.pdf

Tatsuhisa Tsuboi, Matheus P. Viana, Fan Xu, Jingwen Yu, Raghav Chanchani, Ximena G. Arceo, Evelina Tutucci, Joonhyuk Choi, Yang S. Chen, Robert H. Singer, Susanne M. Rafelski, Brian M. Zid

• The authors investigate the physiological impact of nuclear-encoded mitochondrial mRNA localization to mitochondria in yeast
• They observe that as yeast switches to oxidative metabolism, the cytoplasmic density of mitochondria increases (i.e. the ratio of mitochondrial volume to cytoplamic volume)
• Increases in mitochondrial density drives the localisation of nuclear-encoded mitochondrial mRNAs to the mitochondrial surface, increasing mitochondrial protein production
• Sequestering mRNAs away from the mitochondrial surface is sufficient to reduce mitochondrial protein production
• This suggests that mitochondrial density is a physiologically important parameter, which is sensed to regulate mitochondrial gene expression via mRNA localisation.