Metalloprotease OMA1 Fine-tunes Mitochondrial Bioenergetic Function and Respiratory Supercomplex Stability

• Published in: Scientific reports 2015-09, Vol.5 (1), p.13989-13989, Article 13989
• Main Authors: Bohovych, Iryna, Fernandez, Mario R., Rahn, Jennifer J., Stackley, Krista D., Bestman, Jennifer E., Anandhan, Annadurai, Franco, Rodrigo, Claypool, Steven M., Lewis, Robert E., Chan, Sherine S. L., Khalimonchuk, Oleh
• Format: Article
• Language: English
• Subjects: 631/45/468; 631/80/304; Animals; Apoptosis; Bioenergetics; Cell Line; Embryo fibroblasts; Embryo, Nonmammalian - drug effects; Embryo, Nonmammalian - metabolism; Embryos; Energy Metabolism; Homeostasis; Humanities and Social Sciences; Larva - metabolism; Mammalian cells; Metalloproteases - chemistry; Metalloproteases - genetics; Metalloproteases - metabolism; Metalloproteinase; Mice; Mitochondria; Mitochondria - metabolism; Mitochondrial Proteins - chemistry; Mitochondrial Proteins - genetics; Mitochondrial Proteins - metabolism; Morpholinos - pharmacology; multidisciplinary; Phenotype; Physiology; Protein Stability; Quality control; Respiration; Respiratory function; RNA Interference; RNA, Small Interfering - metabolism; Saccharomyces cerevisiae - chemistry; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Science; Yeasts; Zebrafish - growth & development; Zebrafish - metabolism; Zebrafish Proteins - chemistry; Zebrafish Proteins - genetics; Zebrafish Proteins - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep13989

Mitochondria are involved in key cellular functions including energy production, metabolic homeostasis and apoptosis. Normal mitochondrial function is preserved by several interrelated mechanisms. One mechanism – intramitochondrial quality control (IMQC) – is represented by conserved proteases distributed across mitochondrial compartments. Many aspects and physiological roles of IMQC components remain unclear. Here, we show that the IMQC protease Oma1 is required for the stability of the respiratory supercomplexes and thus balanced and tunable bioenergetic function. Loss of Oma1 activity leads to a specific destabilization of respiratory supercomplexes and consequently to unbalanced respiration and progressive respiratory decline in yeast. Similarly, experiments in cultured Oma1-deficient mouse embryonic fibroblasts link together impeded supercomplex stability and inability to maintain proper respiration under conditions that require maximal bioenergetic output. Finally, transient knockdown of OMA1 in zebrafish leads to impeded bioenergetics and morphological defects of the heart and eyes. Together, our biochemical and genetic studies in yeast, zebrafish and mammalian cells identify a novel and conserved physiological role for Oma1 protease in fine-tuning of respiratory function. We suggest that this unexpected physiological role is important for cellular bioenergetic plasticity and may contribute to Oma1-associated disease phenotypes in humans.