Richter 2019 Life Sci Alliance
|Richter U, Ng KY, Suomi F, Marttinen P, Turunen T, Jackson C, Suomalainen A, Vihinen H, Jokitalo E, Nyman TA, Isokallio MA, Stewart JB, Mancini C, Brusco A, Seneca S, Lombès A, Taylor RW, Battersby BJ (2019) Mitochondrial stress response triggered by defects in protein synthesis quality control. Life Sci Alliance 2:e201800219.|
Richter U, Ng KY, Suomi F, Marttinen P, Turunen T, Jackson C, Suomalainen Anu, Vihinen H, Jokitalo E, Nyman TA, Isokallio MA, Stewart JB, Mancini C, Brusco A, Seneca S, Lombes A, Taylor RW, Battersby BJ (2019) Life Sci Alliance
Abstract: Mitochondria have a compartmentalized gene expression system dedicated to the synthesis of membrane proteins essential for oxidative phosphorylation. Responsive quality control mechanisms are needed to ensure that aberrant protein synthesis does not disrupt mitochondrial function. Pathogenic mutations that impede the function of the mitochondrial matrix quality control protease complex composed of AFG3L2 and paraplegin cause a multifaceted clinical syndrome. At the cell and molecular level, defects to this quality control complex are defined by impairment to mitochondrial form and function. Here, we establish the etiology of these phenotypes. We show how disruptions to the quality control of mitochondrial protein synthesis trigger a sequential stress response characterized first by OMA1 activation followed by loss of mitochondrial ribosomes and by remodelling of mitochondrial inner membrane ultrastructure. Inhibiting mitochondrial protein synthesis with chloramphenicol completely blocks this stress response. Together, our data establish a mechanism linking major cell biological phenotypes of AFG3L2 pathogenesis and show how modulation of mitochondrial protein synthesis can exert a beneficial effect on organelle homeostasis.
© 2019 Richter et al.
Labels: MiParea: Respiration, mt-Biogenesis;mt-density, mtDNA;mt-genetics, Genetic knockout;overexpression
Organism: Human Tissue;cell: Fibroblast Preparation: Permeabilized cells
Coupling state: OXPHOS, ET Pathway: N, CIV, NS HRR: Oxygraph-2k