Metabolism
- EglN2 associates with the NRF1‐PGC1α complex and controls mitochondrial function in breast cancer
- Jing Zhang1,†,
- Chengyang Wang2,†,
- Xi Chen3,
- Mamoru Takada1,
- Cheng Fan1,
- Xingnan Zheng1,
- Haitao Wen1,4,
- Yong Liu1,
- Chenguang Wang5,
- Richard G Pestell6,
- Katherine M Aird7,
- William G Kaelin Jr8,9,
- Xiaole Shirley Liu10 and
- Qing Zhang*,1,11
- 1Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- 2Department of Bioinformatics, School of Life Science and Technology, Tongji University, Shanghai, China
- 3Department of Molecular and Cellular Biology, The Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, USA
- 4Department of Surgery, University of North Carolina, Chapel Hill, NC, USA
- 5Program of Radiation Protection and Drug Discovery, Institute of Radiation Medicine, Chinese Academy of Medical Sciences, Peking Union Medical College, Tianjin, China
- 6Department of Cancer Biology and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
- 7Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA, USA
- 8Department of Medical Oncology, Dana‐Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
- 9Howard Hughes Medical Institute, Chevy Chase, MD, USA
- 10Department of Biostatistics and Computational Biology, Dana‐Farber Cancer Institute and Harvard School of Public Health, Boston, MA, USA
- 11Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, USA
- ↵*Corresponding author. Tel: +1 919 843 7887; E‐mail: qing_zhang{at}med.unc.edu
↵† These authors contributed equally to this work
While prolyl hydroxylase EglN2/PHD1 is well known for its role in oxygen‐dependent degradation of HIF1α, this work reports a HIF1‐independent role for EglN2 in regulating mitochondrial function via the formation of a transcription regulatory complex with PGC1α and NRF1.
Synopsis
While prolyl hydroxylase EglN2/PHD1 is well known for its role in oxygen‐dependent degradation of HIF1α, this work reports a HIF1‐independent role for EglN2 in regulating mitochondrial function via the formation of a transcription regulatory complex with PGC1α and NRF1.
EglN2/PHD1 regulates mitochondrial function in ERα‐positive breast cancer under normoxia and hypoxia.
The effect of EglN2 on mitochondrial function is HIF1/2α independent.
EglN2 is an NRF1 binding partner that promotes transcription activation.
EglN2 forms an activator complex with PGC1α and NRF1 on chromatin and promotes FDXR transcription.
FDXR regulates mitochondrial function and contributes to breast tumorigenesis in vitro and in vivo.
The EMBO Journal (2015) 34: 2953–2970
- Received March 3, 2015.
- Revision received September 4, 2015.
- Accepted September 11, 2015.
- © 2015 The Authors
- Phospholipid methylation controls Atg32‐mediated mitophagy and Atg8 recycling
- Kaori Sakakibara1,
- Akinori Eiyama1,†,
- Sho W Suzuki1,2,†,
- Machiko Sakoh‐Nakatogawa2,†,
- Nobuaki Okumura3,†,
- Motohiro Tani4,†,
- Ayako Hashimoto1,
- Sachiyo Nagumo1,
- Noriko Kondo‐Okamoto1,
- Chika Kondo‐Kakuta2,
- Eri Asai2,
- Hiromi Kirisako2,
- Hitoshi Nakatogawa2,
- Osamu Kuge4,
- Toshifumi Takao3,
- Yoshinori Ohsumi2 and
- Koji Okamoto*,1
- 1Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
- 2Frontier Research Center, Tokyo Institute of Technology, Kanagawa, Japan
- 3Institute for Protein Research, Osaka University, Osaka, Japan
- 4Department of Chemistry, Kyushu University, Fukuoka, Japan
- ↵*Corresponding author. Tel: +81 6 6879 7970; E‐mail: kokamoto{at}fbs.osaka-u.ac.jp
↵† These authors contributed equally to this work
The phosphatidylethanolamine (PE) methyltransferase Cho2 is repressed in yeast under non‐fermentable conditions, causing a decrease in the glutathione (GSH) levels and subsequent induction of the mitophagy protein Atg32.
Synopsis
The phosphatidylethanolamine (PE) methyltransferase Cho2 is repressed in yeast under non‐fermentable conditions, causing a decrease in the glutathione (GSH) levels and subsequent induction of the mitophagy protein Atg32.
Loss of phospholipid methyltransferase Opi3 delays Cho2 repression.
Prolonged Cho2 expression causes accumulation of its product phosphatidylmonomethylethanolamine (PMME) and increases the GSH levels, leading to suppression of Atg32 induction and disruption of mitophagy.
Atg8, known to be PE‐linked during autophagosome formation, is aberrantly conjugated to PMME in opi3‐null cells.
Atg8–PMME cannot be efficiently delipidated by the cysteine protease Atg4, thereby attenuating Atg8 recycling and thus mitophagy.
The EMBO Journal (2015) 34: 2703–2719
- Received March 3, 2015.
- Revision received September 3, 2015.
- Accepted September 4, 2015.
- © 2015 The Authors
- Acetyl‐ed question in mitochondrial biology?
Lysine acetylation on numerous mitochondrial proteins, targeted by the sirtuin deacylase SIRT3, has been proposed to play a major role in regulating diverse mitochondrial functions, particularly in the liver. A new study by Weinert, Choudhary, and colleagues, in this issue of The EMBO Journal, finds that the absolute levels of hepatic mitochondrial protein acetylation in wild‐type mice are extremely low and may be insufficient to exert regulatory effects.
See also: BT Weinert et al (November 2015)
New findings of very low acetylation stoichiometry on hepatic mitochondrial proteins question the widespread regulatory significance of SIRT3 deacylase‐targeted lysine acetylation in liver mitochondria.
- © 2015 The Authors
- Analysis of acetylation stoichiometry suggests that SIRT3 repairs nonenzymatic acetylation lesions
- Brian T Weinert*,1,
- Tarek Moustafa2,
- Vytautas Iesmantavicius1,
- Rudolf Zechner3 and
- Chunaram Choudhary*,1
- 1The NNF Center for Protein Research, Faculty of Health Sciences University of Copenhagen, Copenhagen, Denmark
- 2Division of Gastroenterology and Hepatology, Medical University Graz, Graz, Austria
- 3Institute of Molecular Biosciences, University of Graz, Graz, Austria
- ↵*
Corresponding author. Tel: +45 40607184; E‐mail: briantate.weinert{at}cpr.ku.dk
Corresponding author. Tel: +45 35325020; E‐mail: chuna.choudhary{at}cpr.ku.dk
Proteomics analyses show that mitochondrial lysine acetylation occurs as a low‐level non‐enzymatic protein lesion, and SIRT3 deacetylase functions as a protein repair factor removing acetylation lesions.
Synopsis
Proteomics analyses show that mitochondrial lysine acetylation occurs as a low‐level non‐enzymatic protein lesion, and SIRT3 deacetylase functions as a protein repair factor removing acetylation lesions.
Most protein lysine acetylation occurs at a very low stoichiometry.
SIRT3 suppresses acetylation at targeted sites, maintaining low stoichiometry acetylation.
SIRT3‐targeted sites are more sensitive to non‐enzymatic acetylation.
SIRT3‐targeted sites are mostly unaffected by dietary manipulations in wild‐type mice.
The EMBO Journal (2015) 34: 2620–2632
- Received February 12, 2015.
- Revision received August 14, 2015.
- Accepted August 20, 2015.
- © 2015 The Authors. Published under the terms of the CC BY NC ND 4.0 license
This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs 4.0 License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.
- Suppression of miR‐199a maturation by HuR is crucial for hypoxia‐induced glycolytic switch in hepatocellular carcinoma
- Ling‐Fei Zhang1,2,
- Jia‐Tao Lou3,
- Ming‐Hua Lu1,2,
- Chunfang Gao4,
- Shuang Zhao1,2,
- Biao Li5,
- Sheng Liang6,
- Yong Li7,
- Dangsheng Li8 and
- Mo‐Fang Liu*,1,2
- 1Center for RNA Research, State Key Laboratory of Molecular Biology‐University of Chinese Academy of Sciences, Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences, Shanghai, China
- 2Shanghai Key Laboratory of Molecular Andrology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- 3Department of Laboratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
- 4Department of Laboratory Medicine, Eastern Hepatobiliary Surgical Hospital, Second Military Medical University, Shanghai, China
- 5Department of Nuclear Medicine and Micro PET Center, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- 6Department of Nuclear Medicine, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- 7Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
- 8Shanghai Information Center for Life Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
- ↵*Corresponding author. Tel: +86 21 54921146; Fax: +86 21 54921011; E‐mail: mfliu{at}sibcb.ac.cn
Hypoxia drives RNA‐binding protein HuR to block the processing of miR‐199a, thus relieving inhibition of key glycolytic genes Hk2 and Pkm2 and contributing to deregulated glucose metabolism in hepatocellular carcinoma cells.
Synopsis
Hypoxia drives RNA‐binding protein HuR to block the processing of miR‐199a, thus relieving inhibition of key glycolytic genes Hk2 and Pkm2 and contributing to deregulated glucose metabolism in hepatocellular carcinoma cells.
During hypoxia in hepatocellular carcinoma (HCC) cells, RNA‐binding protein HuR binds the primary miR‐199a transcript and represses the formation of mature miRNA.
miR‐199a suppresses Hk2 and Pkm2 in hypoxic HCC cells at both transcriptional and posttranscriptional levels.
The miR‐199a:Hk2/Pkm2 axis is functionally important for regulating glucose metabolism and tumorigenesis.
Systemic delivery of cholesterol‐modified agomiR‐199a effectively inhibits glucose uptake and attenuates tumor growth in HCC tumor‐bearing mice.
The EMBO Journal (2015) 34: 2671–2685
- Received April 15, 2015.
- Revision received August 11, 2015.
- Accepted August 20, 2015.
- © 2015 The Authors
- Lipid droplets and their component triglycerides and steryl esters regulate autophagosome biogenesis
- Tomer Shpilka1,
- Evelyn Welter1,
- Noam Borovsky1,
- Nira Amar1,
- Muriel Mari2,
- Fulvio Reggiori2 and
- Zvulun Elazar*,1
- 1Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel
- 2Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands
- ↵*Corresponding author. Tel: +972 8 9343682; Fax: +972 8 9344112; E‐mail: zvulun.elazar{at}weizmann.ac.il
Under nitrogen starvation, lipid droplet (LD) biogenesis and mobilization enzymes regulate autophagy; the process requires ER‐LD contact site proteins.
Synopsis
Under nitrogen starvation, lipid droplet (LD) biogenesis and mobilization enzymes regulate autophagy; the process requires ER‐LD contact site proteins.
LD biogenesis is pivotal for autophagy under nitrogen starvation in yeast.
Both triacylglycerol and steryl esters are essential for autophagy.
Mobilization of LDs exerted by lipase Ayr1, lipase/hydrolase Ldh1 and hydrolase Yeh1 is important for efficient autophagy.
The ER‐LD contact‐site proteins Ice2 and Ldb16 regulate autophagy.
The EMBO Journal (2015) 34: 2117–2131
- Received October 14, 2014.
- Revision received June 8, 2015.
- Accepted June 9, 2015.
- © 2015 The Authors
- Autophagosomes and lipid droplets: no longer just chewing the fat
- Vojo Deretic (vderetic{at}salud.unm.edu)1
Autophagosomes are organelles capable of sequestering and degrading diverse cytoplasmic cargo for nutritional and quality control purposes. Targeted are also lipid droplets (LDs), the cytoplasmic stores of neutral lipids. In this issue of The EMBO Journal, Shpilka et al (2015) show that the relationship between LDs and autophagosomes is far more intricate and that LDs regulate autophagosome biogenesis.
See also: T Shpilka et al (August 2015)
Recent studies highlight the emerging complex relationship between lipid droplet biology and autophagy.
- © 2015 The Author
- ER–endosome contact sites: molecular compositions and functions
- 1Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- 2Department of Molecular Cell Biology, Institute for Cancer Research Oslo University Hospital, Oslo, Norway
- 3Centre of Molecular Inflammation Research, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- ↵*Corresponding author. Tel: +47 22781818; Fax +47 22781845; E‐mail: stenmark{at}ulrik.uio.no
Membrane contact sites, defined as sites of close apposition between two membranes, are crucial for the direct exchange of information between distinct endomembrane compartments. This review highlights the diverse functions of ER‐endosome contact sites.
The EMBO Journal (2015) 34: 1848–1858
- Received March 10, 2015.
- Revision received March 30, 2015.
- Accepted March 31, 2015.
- © 2015 The Authors
- Reciprocal regulation of amino acid import and epigenetic state through Lat1 and EZH2
- Stephen G Dann*,1,
- Michael Ryskin2,
- Anthony M Barsotti2,
- Jonathon Golas2,
- Celine Shi2,
- Miriam Miranda2,
- Christine Hosselet2,
- Luanna Lemon2,
- Judy Lucas2,
- Maha Karnoub3,
- Fang Wang2,
- Jeremy S Myers2,
- Scott J Garza1,
- Maximillian T Follettie2,
- Kenneth G Geles2,
- Anke Klippel3,
- Robert A Rollins2 and
- Valeria R Fantin1
- 1Pfizer Oncology Research Unit, San Diego, CA, USA
- 2Pfizer Oncology Research Unit, Pearl River, NY, USA
- 3Celgene, Summit, NJ, USA
- ↵*Corresponding author. Tel: +1 845 602 2370; Fax: +1 845 602 5557; E‐mail: stephen.dann{at}pfizer.com
The amino acid transporter Lat1 increases cellular S‐adenosylmethionine concentrations and thereby EZH2 activity, and this dictates the differentiation state of cancer cells and tumour growth.
Synopsis
A metabolic–epigenetic feedback loop between the methionine transporter Lat1 and the histone methyltransferase EZH2 dictates differentiation state in a malignant context.
Cells sorted for high CD98/Lat1 expression contain elevated methionine cycle metabolites and more active EZH2 and are more aggressive in lung cancer models.
Amino acid restriction, methionine dropout, or Lat1 shRNA impairs EZH2 activity due to reduction in cellular S‐adenosylmethionine.
Lat1 and EZH2 expressions correlate with a less‐differentiated state as illustrated by spheroid models of cancer cell differentiation, retinoic acid‐mediated transcription, and immunohistochemical analysis of human lung cancer.
EZH2 activity and PRC2 activity derepress Lat1 expression through direct promoter binding and subsequent transcriptional repression of RXRα.
The EMBO Journal (2015) 34: 1773–1785
- Received February 7, 2014.
- Revision received April 10, 2015.
- Accepted April 14, 2015.
- © 2015 The Authors
- A NAD‐dependent glutamate dehydrogenase coordinates metabolism with cell division in Caulobacter crescentus
- François Beaufay1,
- Jérôme Coppine1,
- Aurélie Mayard1,
- Géraldine Laloux2,
- Xavier De Bolle1 and
- Régis Hallez*,1
- 1Bacterial Cell Cycle & Development (BCcD), URBM, University of Namur, Namur, Belgium
- 2de Duve Institute, Université catholique de Louvain, Brussels, Belgium
- ↵*Corresponding author. Tel: +32 81 724 244; E‐mail: regis.hallez{at}unamur.be
GdhZ and KidO are complementary negative regulators of FtsZ that connect metabolic conditions to cell division in Caulobacter crescentus. GdhZ is an inhibitor of FtsZ polymerization while KidO prevents FtsZ filament bundling in response to nutrient availability.
Synopsis
GdhZ and KidO are metabolic regulators of cell division in Caulobacter crescentus. Once bound to their substrates, both proteins synergistically stimulate cytokinesis by triggering Z‐ring disassembly by two complementary mechanisms in late predivisional cells (G2).
Caulobacter crescentus modulates cell division according to its metabolic activity.
Catalytically active GdhZ stimulates GTPase activity of FtsZ.
KidO bound to NADH inhibits lateral interactions between FtsZ protofilaments.
KidO and GdhZ cooperate to disassemble the Z‐ring.
The EMBO Journal (2015) 34: 1786–1800
- Received December 5, 2014.
- Revision received April 14, 2015.
- Accepted April 21, 2015.
- © 2015 The Authors
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