Mitochondrial stress response triggered by defects in protein synthesis quality control

Uwe Richter, Kah Ying Ng, Fumi Suomi, Paula Marttinen, Taina Turunen, Christopher Jackson, Anu Suomalainen, Helena Vihinen, Eija Jokitalo, Tuula A. Nyman, Marita A. Isokallio, James B. Stewart, Cecilia Mancini, Alfredo Brusco, Sara Seneca, Anne Lombes, Robert W. Taylor, Brendan J. Battersby

Research output: Other contribution

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.

Original languageEnglish
Typee-pub
Media of outputText
Number of pages17
Edition1
Volume2
Publication statusPublished - Feb 2019

Publication series

NameLife science alliance
ISSN (Print)2575-1077

Bibliographical note

© 2019 Richter et al.

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