Lipid signalling drives proteolytic rewiring of mitochondria by YME1L

• DOI: 10.1038/s41586-019-1738-6
• Publication Date: 2019-11-06T19:03:42Z
• Authors: Thomas MacVicar; Yohsuke Ohba; Hendrik Nolte; Fiona Carola Mayer; Takashi Tatsuta; Hans-Georg Sprenger; Barbara Lindner; Yue Zhao; Jiahui Li; Christiane Bruns; Marcus Krüger; Markus Habich; Jan Riemer; Robin Schwarzer; Manolis Pasparakis; Sinika Henschke; Jens C. Brüning; Nicola Zamboni; Thomas Langer
• Keywords: 0301 basic medicine; Metalloendopeptidases; Mechanistic Target of Rapamycin Complex 1; Lipid Metabolism; Lipids; Cell Hypoxia; Cell Line; Mitochondria; Mitochondrial Proteins; 03 medical and health sciences; Proteolysis; ATPases Associated with Diverse Cellular Activities; Humans; Cell Proliferation

Reprogramming of mitochondria provides cells with the metabolic flexibility required to adapt to various developmental transitions such as stem cell activation or immune cell reprogramming, and to respond to environmental challenges such as those encountered under hypoxic conditions or during tumorigenesis1-3. Here we show that the i-AAA protease YME1L rewires the proteome of pre-existing mitochondria in response to hypoxia or nutrient starvation. Inhibition of mTORC1 induces a lipid signalling cascade via the phosphatidic acid phosphatase LIPIN1, which decreases phosphatidylethanolamine levels in mitochondrial membranes and promotes proteolysis. YME1L degrades mitochondrial protein translocases, lipid transfer proteins and metabolic enzymes to acutely limit mitochondrial biogenesis and support cell growth. YME1L-mediated mitochondrial reshaping supports the growth of pancreatic ductal adenocarcinoma (PDAC) cells as spheroids or xenografts. Similar changes to the mitochondrial proteome occur in the tumour tissues of patients with PDAC, suggesting that YME1L is relevant to the pathophysiology of these tumours. Our results identify the mTORC1-LIPIN1-YME1L axis as a post-translational regulator of mitochondrial proteostasis at the interface between metabolism and mitochondrial dynamics.