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Yu Z, Chen J, Takagi E, Wang F, Saha B, Liu X, Joubert LM, Gleason CE, Jin M, Li C, Nowotny C, Agard D, Cheng Y, Pearce D. Interactions between mTORC2 core subunits Rictor and mSin1 dictate selective and context-dependent phosphorylation of substrate kinases SGK1 and Akt. J Biol Chem 2022; 298:102288. [PMID: 35926713 PMCID: PMC9440446 DOI: 10.1016/j.jbc.2022.102288] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 12/02/2022] Open
Abstract
Mechanistic target of rapamycin complex 2 (mTORC2) is a multi-subunit kinase complex, central to multiple essential signaling pathways. Two core subunits, Rictor and mSin1, distinguish it from the related mTORC1 and support context-dependent phosphorylation of its substrates. mTORC2 structures have been determined previously; however, important questions remain, particularly regarding the structural determinants mediating substrate specificity and context-dependent activity. Here, we used cryo-EM to obtain high-resolution structures of the human mTORC2 apo-complex in the presence of substrates Akt and SGK1. Using functional assays, we then tested predictions suggested by substrate-induced structural changes in mTORC2. For the first time, we visualized in the apo-state the side chain interactions between Rictor and mTOR that sterically occlude recruitment of mTORC1 substrates and confer resistance to the mTORC1 inhibitor rapamycin. Also in the apo-state, we observed that mSin1 formed extensive contacts with Rictor via a pair of short α-helices nestled between two Rictor helical repeat clusters, as well as by an extended strand that makes multiple weak contacts with Rictor helical cluster 1. In co-complex structures, we found that SGK1, but not Akt, markedly altered the conformation of the mSin1 N-terminal extended strand, disrupting multiple weak interactions while inducing a large rotation of mSin1 residue Arg-83, which then interacts with a patch of negatively charged residues within Rictor. Finally, we demonstrate mutation of Arg-83 to Ala selectively disrupts mTORC2-dependent phosphorylation of SGK1, but not of Akt, supporting context-dependent substrate selection. These findings provide new structural and functional insights into mTORC2 specificity and context-dependent activity.
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Affiliation(s)
- Zanlin Yu
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Junliang Chen
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Enzo Takagi
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Bidisha Saha
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Xi Liu
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, USA
| | - Lydia-Marie Joubert
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California, USA
| | - Catherine E Gleason
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA
| | - Mingliang Jin
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Chengmin Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Carlos Nowotny
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - David Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California, San Francisco, California, USA; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California, USA
| | - David Pearce
- Department of Medicine, Division of Nephrology, and Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, California, USA.
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Yang AJT, Mohammad A, Tsiani E, Necakov A, MacPherson REK. Chronic AMPK Activation Reduces the Expression and Alters Distribution of Synaptic Proteins in Neuronal SH-SY5Y Cells. Cells 2022; 11:cells11152354. [PMID: 35954198 PMCID: PMC9367429 DOI: 10.3390/cells11152354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
Neuronal growth and synaptic function are dependent on precise protein production and turnover at the synapse. AMPK-activated protein kinase (AMPK) represents a metabolic node involved in energy sensing and in regulating synaptic protein homeostasis. However, there is ambiguity surrounding the role of AMPK in regulating neuronal growth and health. This study examined the effect of chronic AMPK activation on markers of synaptic function and growth. Retinoic-acid-differentiated SH-SY5Y human neuroblastoma cells were treated with A-769662 (100 nM) or Compound C (30 nM) for 1, 3, or 5 days before AMPK, mTORC1, and markers for synapse function were examined. Cell morphology, neuronal marker content, and location were quantified after 5 days of treatment. AMPK phosphorylation was maintained throughout all 5 days of treatment with A-769662 and resulted in chronic mTORC1 inhibition. Lower total, soma, and neuritic neuronal marker contents were observed following 5 d of AMPK activation. Neurite protein abundance and distribution was lower following 5 days of A-769662 treatment. Our data suggest that chronic AMPK activation impacts synaptic protein content and reduces neurite protein abundance and distribution. These results highlight a distinct role that metabolism plays on markers of synapse health and function.
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Affiliation(s)
- Alex J. T. Yang
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
| | - Ahmad Mohammad
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
| | - Evangelia Tsiani
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
| | - Aleksandar Necakov
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada;
- Centre for Neuroscience, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Rebecca E. K. MacPherson
- Department of Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; (A.J.T.Y.); (A.M.); (E.T.)
- Centre for Neuroscience, Brock University, St. Catharines, ON L2S 3A1, Canada
- Correspondence:
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103
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Shams R, Ito Y, Miyatake H. Development of an RHEB-Targeting Peptide To Inhibit mTORC1 Kinase Activity. ACS OMEGA 2022; 7:23479-23486. [PMID: 35847293 PMCID: PMC9280966 DOI: 10.1021/acsomega.2c01865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In cancer, the mechanistic/mammalian target of rapamycin complex-1 (mTORC1) is hyperactivated to promote survival under adverse conditions. The kinase activity of mTORC1 is activated by small-GTPase RHEB-GTP. Therefore, a new modality to inhibit mTORC1 activity has emerged, through intercepting RHEB. However, due to the relatively large contact area involved in the interaction between RHEB and mTORC1, facilitating this inhibition through small molecules has been challenging. Here, we report the development of a peptide that can inhibit the RHEB-mTORC1 interaction. The peptide, P1_WT, was designed based on the α-helix (aa 101-115) of the N-heat domain of mTOR to interact with switch II of RHEB. P1_WT bound to RHEB (K D = 0.14 μM) and inhibited RHEB-mTORN-heat interaction (IC50 = 0.33 μM) in vitro. Consequently, P1_WT inhibited mTORC1 activity at a sub-micromolar level (IC50 ∼ 0.3 μM). P1_WT was predicted to be cell-permeable due to the rich content of arginine (23%), enhancing the intracellular translocation. These results show that P1_WT is a potential compound to further develop inhibitors for mTORC1 by intercepting RHEB from mTORC1.
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Affiliation(s)
- Raef Shams
- Emergent
Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
- Department
of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Saitama 338-8570, Japan
| | - Yoshihiro Ito
- Emergent
Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan
- Nano
Medical Engineering Laboratory, RIKEN Cluster
for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Hideyuki Miyatake
- Department
of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Saitama 338-8570, Japan
- Nano
Medical Engineering Laboratory, RIKEN Cluster
for Pioneering Research, Wako, Saitama 351-0198, Japan
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104
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Tang X, Zhang Y, Wang G, Zhang C, Wang F, Shi J, Zhang T, Ding J. Molecular mechanism of S-adenosylmethionine sensing by SAMTOR in mTORC1 signaling. SCIENCE ADVANCES 2022; 8:eabn3868. [PMID: 35776786 PMCID: PMC10883374 DOI: 10.1126/sciadv.abn3868] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The mechanistic target of rapamycin-mLST8-raptor complex (mTORC1) functions as a central regulator of cell growth and metabolism in response to changes in nutrient signals such as amino acids. SAMTOR is an S-adenosylmethionine (SAM) sensor, which regulates the mTORC1 activity through its interaction with the GTPase-activating protein activity toward Rags-1 (GATOR1)-KPTN, ITFG2, C12orf66 and SZT2-containing regulator (KICSTOR) complex. In this work, we report the crystal structures of Drosophila melanogaster SAMTOR in apo form and in complex with SAM. SAMTOR comprises an N-terminal helical domain and a C-terminal SAM-dependent methyltransferase (MTase) domain. The MTase domain contains the SAM-binding site and the potential GATOR1-KICSTOR-binding site. The helical domain functions as a molecular switch, which undergoes conformational change upon SAM binding and thereby modulates the interaction of SAMTOR with GATOR1-KICSTOR. The functional roles of the key residues and the helical domain are validated by functional assays. Our structural and functional data together reveal the molecular mechanism of the SAM sensing of SAMTOR and its functional role in mTORC1 signaling.
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Affiliation(s)
- Xin Tang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
| | - Yifan Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Guanchao Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Chunxiao Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Fang Wang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jiawen Shi
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University, Sixth People's Hospital of Nantong, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Nantong 226011, China
| | - Tianlong Zhang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
- Institute of Geriatrics, Affiliated Nantong Hospital of Shanghai University, Sixth People's Hospital of Nantong, Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Nantong 226011, China
| | - Jianping Ding
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
- School of Life Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Shanghai 201210, China
- School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Xiangshan Road, Hangzhou 310024, China
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105
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Liu X, Wang X, Chai B, Wu Z, Gu Z, Zou H, Zhang H, Li Y, Sun Q, Fang W, Ma Z. miR-199a-3p/5p regulate tumorgenesis via targeting Rheb in non-small cell lung cancer. Int J Biol Sci 2022; 18:4187-4202. [PMID: 35844793 PMCID: PMC9274486 DOI: 10.7150/ijbs.70312] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 06/05/2022] [Indexed: 12/12/2022] Open
Abstract
Lung cancer is one of the deadliest cancers, in which non-small cell lung cancer (NSCLC) accounting for 85% and has a low survival rate of 5 years. Dysregulation of microRNAs (miRNAs) can participate in tumor regulation and many major diseases. In this study, we found that miR-199a-3p/5p were down-expressed in NSCLC tissue samples, cell lines, and the patient sample database. MiR-199a-3p/5p overexpression could significantly suppress cell proliferation, migration ability and promote apoptosis. Through software prediction, ras homolog enriched in brain (Rheb) was identified as a common target of miR-199a-3p and miR-199a-5p, which participated in regulating mTOR signaling pathway. The same effect of inhibiting NSCLC appeared after down-regulating the expression of Rheb. Furthermore, our findings revealed that miR-199a can significantly inhibit tumor growth and metastasis in vivo, which fully demonstrates that miR-199a plays a tumor suppressive role in NSCLC. In addition, miR-199a-3p/5p has been shown to enhance the sensitivity of gefitinib to EGFR-T790M in NSCLC. Collectively, these results prove that miR-199a-3p/5p can act as cancer suppressor genes to inhibit the mTOR signaling pathway by targeting Rheb, which in turn inhibits the regulatory process of NSCLC. Thus, to investigate the anti-cancer effect of pre-miR-199a/Rheb/mTOR axis in NSCLC, miR-199a-3p and miR-199a-5p have the potential to become an early diagnostic marker or therapeutic target for NSCLC.
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Affiliation(s)
- Xiaomin Liu
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Xianyi Wang
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Binshu Chai
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Zong Wu
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Zhitao Gu
- Department of Thoracic Surgery, Thoracic Cancer Institute, Shanghai Chest Hospital, Jiaotong University Medical School,Shanghai 200030, China
| | - Heng Zou
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Hui Zhang
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Yanli Li
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Qiangling Sun
- Department of Thoracic Surgery, Thoracic Cancer Institute, Shanghai Chest Hospital, Jiaotong University Medical School,Shanghai 200030, China
| | - Wentao Fang
- Department of Thoracic Surgery, Thoracic Cancer Institute, Shanghai Chest Hospital, Jiaotong University Medical School,Shanghai 200030, China
| | - Zhongliang Ma
- Lab for Noncoding RNA & Cancer, School of Life Sciences, Shanghai University, Shanghai 200444, China
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106
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Yue S, Li G, He S, Li T. The central role of mTORC1 in amino acid sensing. Cancer Res 2022; 82:2964-2974. [PMID: 35749594 DOI: 10.1158/0008-5472.can-21-4403] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/28/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
The mechanistic target of rapamycin (mTOR) is a master regulator of cell growth that controls cell homeostasis in response to nutrients, growth factors, and other environmental cues. Recent studies have emphasized the importance of lysosomes as a hub for nutrient sensing, especially amino acid sensing by mTORC1. This review highlights recent advances in understanding the amino acid-mTORC1 signaling axis and the role of mTORC1 in cancer.
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107
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Wang J, Eming SA, Ding X. Role of mTOR Signaling Cascade in Epidermal Morphogenesis and Skin Barrier Formation. BIOLOGY 2022; 11:biology11060931. [PMID: 35741452 PMCID: PMC9220260 DOI: 10.3390/biology11060931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/13/2022] [Accepted: 06/17/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary The skin epidermis is a stratified multilayered epithelium that provides a life-sustaining protective and defensive barrier for our body. The barrier machinery is established and maintained through a tightly regulated keratinocyte differentiation program. Under normal conditions, the basal layer keratinocytes undergo active proliferation and migration upward, differentiating into the suprabasal layer cells. Perturbation of the epidermal differentiation program often results in skin barrier defects and inflammatory skin disorders. The protein kinase mechanistic target of rapamycin (mTOR) is the central hub of cell growth, metabolism and nutrient signaling. Over the past several years, we and others using transgenic mouse models have unraveled that mTOR signaling is critical for epidermal differentiation and barrier formation. On the other hand, there is increasing evidence that disturbed activation of mTOR signaling is significantly implicated in the development of various skin diseases. In this review, we focus on the formation of skin barrier and discuss the current understanding on how mTOR signaling networks, including upstream inputs, kinases and downstream effectors, regulate epidermal differentiation and skin barrier formation. We hope this review will help us better understand the metabolic signaling in the epidermis, which may open new vistas for epidermal barrier defect-associated disease therapy. Abstract The skin epidermis, with its capacity for lifelong self-renewal and rapid repairing response upon injury, must maintain an active status in metabolism. Mechanistic target of rapamycin (mTOR) signaling is a central controller of cellular growth and metabolism that coordinates diverse physiological and pathological processes in a variety of tissues and organs. Recent evidence with genetic mouse models highlights an essential role of the mTOR signaling network in epidermal morphogenesis and barrier formation. In this review, we focus on the recent advances in understanding how mTOR signaling networks, including upstream inputs, kinases and downstream effectors, regulate epidermal morphogenesis and skin barrier formation. Understanding the details of the metabolic signaling will be critical for the development of novel pharmacological approaches to promote skin barrier regeneration and to treat epidermal barrier defect-associated diseases.
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Affiliation(s)
- Juan Wang
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People’s Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China;
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China
| | - Sabine A. Eming
- Department of Dermatology, University of Cologne, 50937 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
- Institute of Zoology, Developmental Biology Unit, University of Cologne, 50674 Cologne, Germany
- Correspondence: (S.A.E.); (X.D.); Tel.: +86-137-6457-1130 (X.D.)
| | - Xiaolei Ding
- Institute of Geriatrics (Shanghai University), Affiliated Nantong Hospital of Shanghai University (The Sixth People’s Hospital of Nantong), School of Medicine, Shanghai University, Nantong 226011, China;
- Shanghai Engineering Research Center of Organ Repair, School of Medicine, Shanghai University, Shanghai 200444, China
- Department of Dermatology, University of Cologne, 50937 Cologne, Germany
- Correspondence: (S.A.E.); (X.D.); Tel.: +86-137-6457-1130 (X.D.)
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108
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Stress- and metabolic responses of Candida albicans require Tor1 kinase N-terminal HEAT repeats. PLoS Pathog 2022; 18:e1010089. [PMID: 35687592 PMCID: PMC9223334 DOI: 10.1371/journal.ppat.1010089] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 06/23/2022] [Accepted: 05/12/2022] [Indexed: 11/19/2022] Open
Abstract
Whether to commit limited cellular resources toward growth and proliferation, or toward survival and stress responses, is an essential determination made by Target of Rapamycin Complex 1 (TORC1) for a eukaryotic cell in response to favorable or adverse conditions. Loss of TORC1 function is lethal. The TORC1 inhibitor rapamycin that targets the highly conserved Tor kinase domain kills fungal pathogens like Candida albicans, but is also severely toxic to human cells. The least conserved region of fungal and human Tor kinases are the N-terminal HEAT domains. We examined the role of the 8 most N-terminal HEAT repeats of C. albicans Tor1. We compared nutritional- and stress responses of cells that express a message for N-terminally truncated Tor1 from repressible tetO, with cells expressing wild type TOR1 from tetO or from the native promoter. Some but not all stress responses were significantly impaired by loss of Tor1 N-terminal HEAT repeats, including those to oxidative-, cell wall-, and heat stress; in contrast, plasma membrane stress and antifungal agents that disrupt plasma membrane function were tolerated by cells lacking this Tor1 region. Translation was inappropriately upregulated during oxidative stress in cells lacking N-terminal Tor1 HEAT repeats despite simultaneously elevated Gcn2 activity, while activation of the oxidative stress response MAP kinase Hog1 was weak. Conversely, these cells were unable to take advantage of favorable nutritional conditions by accelerating their growth. Consuming oxygen more slowly than cells containing wild type TOR1 alleles during growth in glucose, cells lacking N-terminal Tor1 HEAT repeats additionally were incapable of utilizing non-fermentable carbon sources. They were also hypersensitive to inhibitors of specific complexes within the respiratory electron transport chain, suggesting that inefficient ATP generation and a resulting dearth of nucleotide sugar building blocks for cell wall polysaccharides causes cell wall integrity defects in these mutants. Genome-wide expression analysis of cells lacking N-terminal HEAT repeats showed dysregulation of carbon metabolism, cell wall biosynthetic enzymes, translational machinery biosynthesis, oxidative stress responses, and hyphal- as well as white-opaque cell type-associated genes. Targeting fungal-specific Tor1 N-terminal HEAT repeats with small molecules might selectively abrogate fungal viability, especially when during infection multiple stresses are imposed by the host immune system. Whether growing harmlessly on our mucous membranes in competition with bacterial multitudes, or invading our tissues and bloodstream, the fungus Candida albicans must be capable of rapid growth when it finds abundant nutrients and favorable conditions. It must also be able to switch to stress- and survival mode when encountering host immune cells and when starving for nutrients. Tor1 kinase is the central regulator at the heart of these cellular decisions. As an essential protein, it is an attractive drug target. But the Tor1 kinase domain is very similar to its human counterpart, rendering its inhibitors like rapamycin toxic for humans. We identified a region of helical protein-protein interaction domains, the N-terminal HEAT repeats, as the least conserved part of C. albicans Tor1. Using genetic- and genome-wide expression analysis, we found that 8 N-terminal HEAT repeats are required for growth acceleration in nutrient-rich environments and for decreased translation in starvation- and stress conditions. This Tor1 region contributes to oxidative-, cell wall- and heat stress reponses, to hyphal growth and to respiration, but apparently not to plasma membrane stress endurance or fermentation. Small molecules that disrupt the protein-protein interactions mediated by this region could become fungal-selective inhibitors of Tor kinase.
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109
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Trautman ME, Richardson NE, Lamming DW. Protein restriction and branched-chain amino acid restriction promote geroprotective shifts in metabolism. Aging Cell 2022; 21:e13626. [PMID: 35526271 PMCID: PMC9197406 DOI: 10.1111/acel.13626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 04/13/2022] [Accepted: 04/21/2022] [Indexed: 01/20/2023] Open
Abstract
The proportion of humans suffering from age‐related diseases is increasing around the world, and creative solutions are needed to promote healthy longevity. Recent work has clearly shown that a calorie is not just a calorie—and that low protein diets are associated with reduced mortality in humans and promote metabolic health and extended lifespan in rodents. Many of the benefits of protein restriction on metabolism and aging are the result of decreased consumption of the three branched‐chain amino acids (BCAAs), leucine, isoleucine, and valine. Here, we discuss the emerging evidence that BCAAs are critical modulators of healthy metabolism and longevity in rodents and humans, as well as the physiological and molecular mechanisms that may drive the benefits of BCAA restriction. Our results illustrate that protein quality—the specific composition of dietary protein—may be a previously unappreciated driver of metabolic dysfunction and that reducing dietary BCAAs may be a promising new approach to delay and prevent diseases of aging.
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Affiliation(s)
- Michaela E. Trautman
- Department of Medicine University of Wisconsin‐Madison Madison Wisconsin USA
- William S. Middleton Memorial Veterans Hospital Madison Wisconsin USA
- Interdepartmental Graduate Program in Nutritional Sciences University of Wisconsin‐Madison Madison Wisconsin USA
| | - Nicole E. Richardson
- Department of Medicine University of Wisconsin‐Madison Madison Wisconsin USA
- William S. Middleton Memorial Veterans Hospital Madison Wisconsin USA
- Endocrinology and Reproductive Physiology Graduate Training Program University of Wisconsin‐Madison Madison Wisconsin USA
| | - Dudley W. Lamming
- Department of Medicine University of Wisconsin‐Madison Madison Wisconsin USA
- William S. Middleton Memorial Veterans Hospital Madison Wisconsin USA
- Endocrinology and Reproductive Physiology Graduate Training Program University of Wisconsin‐Madison Madison Wisconsin USA
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110
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mTOR substrate phosphorylation in growth control. Cell 2022; 185:1814-1836. [PMID: 35580586 DOI: 10.1016/j.cell.2022.04.013] [Citation(s) in RCA: 132] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 12/20/2022]
Abstract
The target of rapamycin (TOR), discovered 30 years ago, is a highly conserved serine/threonine protein kinase that plays a central role in regulating cell growth and metabolism. It is activated by nutrients, growth factors, and cellular energy. TOR forms two structurally and functionally distinct complexes, TORC1 and TORC2. TOR signaling activates cell growth, defined as an increase in biomass, by stimulating anabolic metabolism while inhibiting catabolic processes. With emphasis on mammalian TOR (mTOR), we comprehensively reviewed the literature and identified all reported direct substrates. In the context of recent structural information, we discuss how mTORC1 and mTORC2, despite having a common catalytic subunit, phosphorylate distinct substrates. We conclude that the two complexes recruit different substrates to phosphorylate a common, minimal motif.
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111
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Preparation of Novel Pyrazolo[4,3- e]tetrazolo[1,5- b][1,2,4]triazine Sulfonamides and Their Experimental and Computational Biological Studies. Int J Mol Sci 2022; 23:ijms23115892. [PMID: 35682571 PMCID: PMC9180621 DOI: 10.3390/ijms23115892] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/16/2022] [Accepted: 05/17/2022] [Indexed: 02/04/2023] Open
Abstract
Pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine sulfonamides constitute a novel class of heterocyclic compounds with broad biological activity, including anticancer properties. Investigated in this study, MM-compounds (MM134, MM136, MM137, and MM139) exhibited cytotoxic and proapoptotic activity against cancer cell lines (BxPC-3, PC-3, and HCT-116) in nanomolar concentrations without causing cytotoxicity in normal cells (L929 and WI38). In silico predictions indicate that tested compounds exhibit favorable pharmacokinetic profiles and may exert anticancer activity through the inhibition of BTK kinase, the AKT-mTOR pathway and PD1-PD-L1 interaction. Our findings point out that these sulfonamide derivatives may constitute a source of new anticancer drugs after optimization.
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112
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Ma S, Dong Z, Huang Y, Liu JY, Zhang JT. Translation initiation factor eIF3a regulates glucose metabolism and cell proliferation via promoting small GTPase Rheb synthesis and AMPK activation. J Biol Chem 2022; 298:102044. [PMID: 35595099 PMCID: PMC9207673 DOI: 10.1016/j.jbc.2022.102044] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 12/05/2022] Open
Abstract
Eukaryotic translation initiation factor 3 subunit A (eIF3a), the largest subunit of the eIF3 complex, has been shown to be overexpressed in malignant cancer cells, potentially making it a proto-oncogene. eIF3a overexpression can drive cancer cell proliferation but contributes to better prognosis. While its contribution to prognosis was previously shown to be due to its function in suppressing synthesis of DNA damage repair proteins, it remains unclear how eIF3a regulates cancer cell proliferation. In this study, we show using genetic approaches that eIF3a controls cell proliferation by regulating glucose metabolism via the phosphorylation and activation of AMP-activated protein kinase alpha (AMPKα) at Thr172 in its kinase activation loop. We demonstrate that eIF3a regulates AMPK activation mainly by controlling synthesis of the small GTPase Rheb, largely independent of the well-known AMPK upstream liver kinase B1 and Ca2+/calmodulin-dependent protein kinase kinase 2, and also independent of mammalian target of rapamycin signaling and glucose levels. Our findings suggest that glucose metabolism in and proliferation of cancer cells may be translationally regulated via a novel eIF3a–Rheb–AMPK signaling axis.
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Affiliation(s)
- Shijie Ma
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Zizheng Dong
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Yanfei Huang
- Department of Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Jing-Yuan Liu
- Department of Medicine, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA
| | - Jian-Ting Zhang
- Department of Cell and Cancer Biology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, USA.
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113
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Meng D, Yang Q, Jeong MH, Curukovic A, Tiwary S, Melick CH, Lama-Sherpa TD, Wang H, Huerta-Rosario M, Urquhart G, Zacharias LG, Lewis C, DeBerardinis RJ, Jewell JL. SNAT7 regulates mTORC1 via macropinocytosis. Proc Natl Acad Sci U S A 2022; 119:e2123261119. [PMID: 35561222 PMCID: PMC9171778 DOI: 10.1073/pnas.2123261119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/13/2022] [Indexed: 11/30/2022] Open
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) senses amino acids to control cell growth, metabolism, and autophagy. Some amino acids signal to mTORC1 through the Rag GTPase, whereas glutamine and asparagine activate mTORC1 through a Rag GTPase-independent pathway. Here, we show that the lysosomal glutamine and asparagine transporter SNAT7 activates mTORC1 after extracellular protein, such as albumin, is macropinocytosed. The N terminus of SNAT7 forms nutrient-sensitive interaction with mTORC1 and regulates mTORC1 activation independently of the Rag GTPases. Depletion of SNAT7 inhibits albumin-induced mTORC1 lysosomal localization and subsequent activation. Moreover, SNAT7 is essential to sustain KRAS-driven pancreatic cancer cell growth through mTORC1. Thus, SNAT7 links glutamine and asparagine signaling from extracellular protein to mTORC1 independently of the Rag GTPases and is required for macropinocytosis-mediated mTORC1 activation and pancreatic cancer cell growth.
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Affiliation(s)
- Delong Meng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Qianmei Yang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Mi-Hyeon Jeong
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Adna Curukovic
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Shweta Tiwary
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Chase H. Melick
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Tshering D. Lama-Sherpa
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Huanyu Wang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Mariela Huerta-Rosario
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Greg Urquhart
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Lauren G. Zacharias
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Cheryl Lewis
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Ralph J. DeBerardinis
- Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jenna L. Jewell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
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114
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Yue J, Aobulikasimu A, Sun W, Liu S, Xie W, Sun W. Targeted regulation of FoxO1 in chondrocytes prevents age-related osteoarthritis via autophagy mechanism. J Cell Mol Med 2022; 26:3075-3082. [PMID: 35560791 PMCID: PMC9170816 DOI: 10.1111/jcmm.17319] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/17/2022] [Accepted: 03/30/2022] [Indexed: 11/30/2022] Open
Abstract
Autophagy is designated as a biological recycling process to maintain cellular homeostasis by the sequestration of damaged proteins and organelles in plasma and cargo delivery to lysosomes for degradation and reclamation. This organelle recycling process promotes chondrocyte homeostasis and has been previously implicated in osteoarthritis (OA). Autophagy is widely involved in regulating chondrocyte degeneration markers such as MMPs, ADAMSTs and Col10 in chondrocytes. The critical autophagy‐related (ATG) proteins have now been considered the protective factor against late‐onset OA. The current research field proposes that the autophagic pathway is closely related to chondrocyte activity. However, the mechanism is complex yet needs precise elaboration. This review concluded that FoxO1, a forkhead O family protein, which is a decisive mediator of autophagy, facilitates the pathological process of osteoarthritis. Diverse mechanisms regulate the activity of FoxO1 and promote the initiation of autophagy, including the prominent AMPK and Sirt‐2 cellular pathways. FoxO1 transactive is regulated by phosphorylation and acetylation processes, which modulates the downstream ATGs expression. Furthermore, FoxO1 induces autophagy by directly interacting with ATGs proteins, which control the formation of autophagosomes and lysosomes fusion. This review will discuss cutting‐edge evidence that the FoxO–autophagy pathway plays an essential regulator in the pathogenesis of osteoarthritis.
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Affiliation(s)
- Jiaji Yue
- Department of Bone and Joint Surgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Aikebaier Aobulikasimu
- Department of Bone and Joint Surgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Weichao Sun
- Department of Bone and Joint Surgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Shuyu Liu
- Department of Bone and Joint Surgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Wei Xie
- Department of Bone and Joint Surgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Wei Sun
- Department of Bone and Joint Surgery, Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
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115
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APEX2-Mediated Proximity Labeling Resolves the DDIT4-Interacting Proteome. Int J Mol Sci 2022; 23:ijms23095189. [PMID: 35563580 PMCID: PMC9102673 DOI: 10.3390/ijms23095189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/03/2022] [Accepted: 05/04/2022] [Indexed: 11/17/2022] Open
Abstract
DNA damage-inducible transcript 4 (DDIT4) is a ubiquitous protein whose expression is transiently increased in response to various stressors. Chronic expression has been linked to various pathologies, including neurodegeneration, inflammation, and cancer. DDIT4 is best recognized for repressing mTORC1, an essential protein complex activated by nutrients and hormones. Accordingly, DDIT4 regulates metabolism, oxidative stress, hypoxic survival, and apoptosis. Despite these well-defined biological functions, little is known about its interacting partners and their unique molecular functions. Here, fusing an enhanced ascorbate peroxidase 2 (APEX2) biotin-labeling enzyme to DDIT4 combined with mass spectrometry, the proteins in the immediate vicinity of DDIT4 in either unstressed or acute stress conditions were identified in situ. The context-dependent interacting proteomes were quantitatively but not functionally distinct. DDIT4 had twice the number of interaction partners during acute stress compared to unstressed conditions, and while the two protein lists had minimal overlap in terms of identity, the proteins’ molecular function and classification were essentially identical. Moonlighting keratins and ribosomal proteins dominated the proteomes in both unstressed and stressed conditions, with many of their members having established non-canonical and indispensable roles during stress. Multiple keratins regulate mTORC1 signaling via the recruitment of 14-3-3 proteins, whereas ribosomal proteins control translation, cell cycle progression, DNA repair, and death by sequestering critical proteins. In summary, two potentially distinct mechanisms of DDIT4 molecular function have been identified, paving the way for additional research to confirm and consolidate these findings.
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116
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Wang T. Searching for the link between inflammaging and sarcopenia. Ageing Res Rev 2022; 77:101611. [PMID: 35307560 DOI: 10.1016/j.arr.2022.101611] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/14/2022] [Accepted: 03/15/2022] [Indexed: 12/17/2022]
Affiliation(s)
- Tiantian Wang
- Institute of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; Department of Rehabilitation Medicine, Key Laboratory of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China.
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117
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Oleksak P, Nepovimova E, Chrienova Z, Musilek K, Patocka J, Kuca K. Contemporary mTOR inhibitor scaffolds to diseases breakdown: A patent review (2015–2021). Eur J Med Chem 2022; 238:114498. [DOI: 10.1016/j.ejmech.2022.114498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/16/2022] [Accepted: 05/26/2022] [Indexed: 02/06/2023]
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118
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Gao H, Xian G, Zhong G, Huang B, Liang S, Zeng Q, Liu Y. Alleviation of doxorubicin-induced cardiomyocyte death through miR-147-y-mediated mitophagy. Biochem Biophys Res Commun 2022; 609:176-182. [PMID: 35452958 DOI: 10.1016/j.bbrc.2022.04.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/23/2022] [Accepted: 04/05/2022] [Indexed: 12/15/2022]
Abstract
Doxorubicin (DOX) is a commonly used antitumor drug. However, it may cause severe cardiotoxicity, apoptosis being a major change. A recent report indicates that miR-147 expression is decreased in the myocardium of a myocardial infarction model, suggesting a potential role of this miRNA in DOX-induced cardiomyocyte toxicity. In this study, freshly isolated neonatal pig cardiomyocytes were used; following transfection of a miR-147-y mimic, the cell death induced by DOX was alleviated, represented by augmented mitophagy [indicated by a decrease in P62, and increases in LC3, PINK1, parkin mRNA, LC3Ⅱ/Ⅰ, beclin-1, PINK1, and parkin including p-parkin (Ser65) protein expression], prohibited cell apoptosis as determined by TUNEL staining, and the suppression of caspase-3 transcription and cleaved caspase-3 translation. In cells transfected with an miR-147-y inhibitor, DOX-induced mitophagy was decreased, while apoptosis was increased. Additionally, RAPTOR gene silencing in cardiomyocytes exposed to DOX increased the rate of mitophagy and decreased that of apoptosis as compared with the treatment with DOX alone. Moreover, RAPTOR overexpression downregulated the rate of mitophagy and increased that of apoptosis in cells exposed to DOX. RAPTOR was confirmed as the target gene of miR-147-y based on the results of luciferase reporter gene assays and the opposite effects of the miR-147-y mimic and miR-147-y inhibitor on RAPTOR expression. In summary, our study suggests that miR-147-y mediates DOX-induced cardiomyocyte mitophagy while suppresses apoptosis by targeting RAPTOR, thus playing a protective role in DOX-induced cardiomyocyte damage.
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Affiliation(s)
- Hongbin Gao
- Department of Toxicology, School of Public Health (Guangdong Provincial Key Laboratory of Tropical Disease Research), Southern Medical University, Guangzhou, 510515, China; Guangdong Laboratory Animals Monitoring Institute (Guangdong Provincial Key Laboratory of Laboratory Animals), Guangzhou, 510663, China
| | - Gaopeng Xian
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, 510005, China; Department of Cardiology (Guangdong Provincial Key Laboratory of Shock and Microcirculation), Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Guoheng Zhong
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, 510005, China; Department of Cardiology (Guangdong Provincial Key Laboratory of Shock and Microcirculation), Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Bihong Huang
- Guangdong Laboratory Animals Monitoring Institute (Guangdong Provincial Key Laboratory of Laboratory Animals), Guangzhou, 510663, China
| | - Shi Liang
- Guangdong Laboratory Animals Monitoring Institute (Guangdong Provincial Key Laboratory of Laboratory Animals), Guangzhou, 510663, China
| | - Qingchun Zeng
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, 510005, China; Department of Cardiology (Guangdong Provincial Key Laboratory of Shock and Microcirculation), Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
| | - Yungang Liu
- Department of Toxicology, School of Public Health (Guangdong Provincial Key Laboratory of Tropical Disease Research), Southern Medical University, Guangzhou, 510515, China.
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119
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Gregorio JD, Petricca S, Iorio R, Toniato E, Flati V. MITOCHONDRIAL AND METABOLIC ALTERATIONS IN CANCER CELLS. Eur J Cell Biol 2022; 101:151225. [DOI: 10.1016/j.ejcb.2022.151225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 04/11/2022] [Accepted: 04/11/2022] [Indexed: 02/07/2023] Open
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120
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Melick CH, Lama-Sherpa TD, Curukovic A, Jewell JL. G-Protein Coupled Receptor Signaling and Mammalian Target of Rapamycin Complex 1 Regulation. Mol Pharmacol 2022; 101:181-190. [PMID: 34965982 PMCID: PMC9092479 DOI: 10.1124/molpharm.121.000302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 11/29/2021] [Indexed: 11/30/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) senses upstream stimuli to regulate numerous cellular functions such as metabolism, growth, and autophagy. Increased activation of mTOR complex 1 (mTORC1) is typically observed in human disease and continues to be an important therapeutic target. Understanding the upstream regulators of mTORC1 will provide a crucial link in targeting hyperactivated mTORC1 in human disease. In this mini-review, we will discuss the regulation of mTORC1 by upstream stimuli, with a specific focus on G-protein coupled receptor signaling to mTORC1. SIGNIFICANCE STATEMENT: mTORC1 is a master regulator of many cellular processes and is often hyperactivated in human disease. Therefore, understanding the molecular underpinnings of G-protein coupled receptor signaling to mTORC1 will undoubtedly be beneficial for human disease.
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Affiliation(s)
- Chase H Melick
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Tshering D Lama-Sherpa
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Adna Curukovic
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Jenna L Jewell
- Department of Molecular Biology, Harold C. Simmons Comprehensive Cancer, and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
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121
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Simcox J, Lamming DW. The central moTOR of metabolism. Dev Cell 2022; 57:691-706. [PMID: 35316619 PMCID: PMC9004513 DOI: 10.1016/j.devcel.2022.02.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/20/2022] [Accepted: 02/24/2022] [Indexed: 12/21/2022]
Abstract
The protein kinase mechanistic target of rapamycin (mTOR) functions as a central regulator of metabolism, integrating diverse nutritional and hormonal cues to control anabolic processes, organismal physiology, and even aging. This review discusses the current state of knowledge regarding the regulation of mTOR signaling and the metabolic regulation of the four macromolecular building blocks of the cell: carbohydrate, nucleic acid, lipid, and protein by mTOR. We review the role of mTOR in the control of organismal physiology and aging through its action in key tissues and discuss the potential for clinical translation of mTOR inhibition for the treatment and prevention of diseases of aging.
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Affiliation(s)
- Judith Simcox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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122
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Dal Cortivo G, Dell’Orco D. Calcium- and Integrin-Binding Protein 2 (CIB2) in Physiology and Disease: Bright and Dark Sides. Int J Mol Sci 2022; 23:ijms23073552. [PMID: 35408910 PMCID: PMC8999013 DOI: 10.3390/ijms23073552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/19/2022] [Accepted: 03/22/2022] [Indexed: 12/04/2022] Open
Abstract
Calcium- and integrin-binding protein 2 (CIB2) is a small EF-hand protein capable of binding Mg2+ and Ca2+ ions. While its biological function remains largely unclear, an increasing number of studies have shown that CIB2 is an essential component of the mechano-transduction machinery that operates in cochlear hair cells. Mutations in the gene encoding CIB2 have been associated with non-syndromic deafness. In addition to playing an important role in the physiology of hearing, CIB2 has been implicated in a multitude of very different processes, ranging from integrin signaling in platelets and skeletal muscle to autophagy, suggesting extensive functional plasticity. In this review, we summarize the current understanding of biochemical and biophysical properties of CIB2 and the biological roles that have been proposed for the protein in a variety of processes. We also highlight the many molecular aspects that remain unclarified and deserve further investigation.
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123
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Tsverov J, Yegorov K, Powers T. Identification of defined structural elements within TOR2 kinase required for TOR Complex 2 assembly and function in S. cerevisiae. Mol Biol Cell 2022; 33:ar44. [PMID: 35293776 PMCID: PMC9282017 DOI: 10.1091/mbc.e21-12-0611] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
mTOR is a large protein kinase that assembles into two multi-subunit protein complexes, mTORC1 and mTORC2, to regulate cell growth in eukaryotic cells. While significant progress has been made in our understanding of the composition and structure of these complexes, important questions remain regarding the role of specific sequences within mTOR important for complex formation and activity. To address these issues, we have used a molecular genetic approach to explore TOR Complex assembly in budding yeast, where two closely related TOR paralogs, TOR1 and TOR2, partition preferentially into TORC1 versus TORC2, respectively. We previously identified a ∼500 amino acid segment within the N-terminal half of each protein, termed the Major Assembly Specificity (MAS) Domain, which can govern specificity in formation of each complex. In this study, we have extended the use of chimeric TOR1-TOR2 genes as a "sensitized" genetic system to identify specific subdomains rendered essential for TORC2 function, using synthetic lethal interaction analyses. Our findings reveal important design principles underlying the dimeric assembly of TORC2, as well as identify specific segments within the MAS domain critical for TORC2 function, to a level approaching single amino acid resolution. Together these findings highlight the complex and cooperative nature of TOR Complex assembly and function.
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Affiliation(s)
- Jennifer Tsverov
- Department of Molecular and Cellular Biology, College of Biological Sciences, UC Davis
| | - Kristina Yegorov
- Department of Molecular and Cellular Biology, College of Biological Sciences, UC Davis
| | - Ted Powers
- Department of Molecular and Cellular Biology, College of Biological Sciences, UC Davis
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124
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Du C, Yang W, Yu Z, Yuan Q, Pang D, Tang P, Jiang W, Chen M, Xiao B. Rheb Promotes Triglyceride Secretion and Ameliorates Diet-Induced Steatosis in the Liver. Front Cell Dev Biol 2022; 10:808140. [PMID: 35372326 PMCID: PMC8965806 DOI: 10.3389/fcell.2022.808140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Hepatosteatosis, characterized by excessive accumulation of lipids in the liver, is a major health issue in modern society. Understanding how altered hepatic lipid metabolism/homeostasis causes hepatosteatosis helps to develop therapeutic interventions. Previous studies identify mitochondrial dysfunction as a contributor to hepatosteatosis. But, the molecular mechanisms of mitochondrial dysfunction leading to altered lipid metabolism remain incompletely understood. Our previous work shows that Rheb, a Ras-like small GTPase, not only activates mTORC1 but also promotes mitochondrial ATP production through pyruvate dehydrogenase (PDH). In this study, we further demonstrate that Rheb controls hepatic triglyceride secretion and reduces diet-induced lipid accumulation in a mouse liver. Genetic deletion of Rheb causes rapid and spontaneous steatosis in the liver, which is unexpected from the role of mTORC1 that enhances lipid synthesis, whereas Rheb transgene remarkably reduces diet-induced hepatosteatosis. Results suggest that the hepatosteatosis in Rheb KO is an outcome of impaired lipid secretion, which is linked to mitochondrial ATP production of hepatocytes. Our findings highlight an under-appreciated role of Rheb in the regulation of hepatic lipid secretion through mitochondrial energy production, with therapeutic implication.
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Affiliation(s)
- Chongyangzi Du
- Neuroscience and Metabolism Research, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Wanchun Yang
- Neuroscience and Metabolism Research, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, China
| | - Zongyan Yu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Biology, School of Life Sciences, Brain Research Center, Southern University of Science and Technology, Shenzhen, China
| | - Qiuyun Yuan
- Neuroscience and Metabolism Research, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Dejiang Pang
- Neuroscience and Metabolism Research, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Ping Tang
- Neuroscience and Metabolism Research, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Wanxiang Jiang
- Neuroscience and Metabolism Research, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Mina Chen
- Neuroscience and Metabolism Research, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
- Correspondence: Bo Xiao, ; Mina Chen, .
| | - Bo Xiao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
- Department of Biology, School of Life Sciences, Brain Research Center, Southern University of Science and Technology, Shenzhen, China
- Correspondence: Bo Xiao, ; Mina Chen, .
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125
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de Melo Madureira ÁN, de Oliveira JRS, de Menezes Lima VL. The Role of IL-6 Released During Exercise to Insulin Sensitivity and Muscle Hypertrophy. Mini Rev Med Chem 2022; 22:2419-2428. [PMID: 35264090 DOI: 10.2174/1389557522666220309161245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/25/2021] [Accepted: 01/27/2022] [Indexed: 11/22/2022]
Abstract
Interleukin-6 (IL-6) influences both inflammatory response and anti-inflammatory processes. This cytokine can be released by the exercising skeletal muscle, which characterizes it as a myokine. Unlike what is observed in inflammation, IL-6 produced by skeletal muscle is not preceded by the release of other pro-inflammatory cytokines, but is seems to be dependent on the lactate produced during exercise, thus causing different effects from those of seen in inflammatory state. After binding to its receptor, myokine IL-6 activates the PI3K-Akt pathway. One consequence of this upregulation is the potentiation of insulin signaling, which enhances insulin sensitivity. IL-6 increases GLUT-4 vesicle mobilization to muscle cell periphery, increasing the glucose transport into the cell, and also glycogen synthesis. Muscle glycogen provides energy for the ATP resynthesis, and regulates Ca2+ release by the sarcoplasmic reticulum, influencing muscle contraction, and, hence, muscle function by multiple pathways. Another implication for the upregulation of PI3K-Akt pathway is the activation of mTORC1, which regulates mRNA translational efficiency by regulating translation machinery, and translational capacity by inducing ribosomal biogenesis. Thus, IL-6 may contribute for skeletal muscle hypertrophy and function by increasing contractile protein synthesis.
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Affiliation(s)
- Álvaro Nóbrega de Melo Madureira
- Laboratory of Lipids and Application of Biomolecules to Prevalent and Neglected Diseases (LAB-DPN), Department of Biochemistry, Federal University of Pernambuco (UFPE)
| | - João Ricardhis Saturnino de Oliveira
- Laboratory of Lipids and Application of Biomolecules to Prevalent and Neglected Diseases (LAB-DPN), Department of Biochemistry, Federal University of Pernambuco (UFPE)
| | - Vera Lúcia de Menezes Lima
- Laboratory of Lipids and Application of Biomolecules to Prevalent and Neglected Diseases (LAB-DPN), Department of Biochemistry, Federal University of Pernambuco (UFPE)
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Zhong Y, Zhou X, Guan KL, Zhang J. Rheb regulates nuclear mTORC1 activity independent of farnesylation. Cell Chem Biol 2022; 29:1037-1045.e4. [PMID: 35294906 DOI: 10.1016/j.chembiol.2022.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 10/26/2021] [Accepted: 02/10/2022] [Indexed: 11/26/2022]
Abstract
The small GTPase Ras homolog enriched in brain (Rheb) plays a critical role in activating the mechanistic target of rapamycin complex 1 (mTORC1), a signaling hub that regulates various cellular functions. We recently observed nuclear mTORC1 activity, raising an intriguing question as to how Rheb, which is known to be farnesylated and localized to intracellular membranes, regulates nuclear mTORC1. In this study, we found that active Rheb is present in the nucleus and required for nuclear mTORC1 activity. We showed that inhibition of farnesyltransferase reduced cytosolic, but not nuclear, mTORC1 activity. Furthermore, a farnesylation-deficient Rheb mutant, with preferential nuclear localization and specific lysosome tethering, enables nuclear and cytosolic mTORC1 activities, respectively. These data suggest that non-farnesylated Rheb is capable of interacting with and activating mTORC1, providing mechanistic insights into the molecular functioning of Rheb as well as regulation of the recently observed, active pool of nuclear mTORC1.
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Affiliation(s)
- Yanghao Zhong
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA, USA
| | - Xin Zhou
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
| | - Kun-Liang Guan
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA; Moores Cancer Center, University of California, San Diego, La Jolla, CA, USA; Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA; Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA.
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127
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Kapur P, Gao M, Zhong H, Chintalapati S, Mitui M, Barnes S, Zhou Q, Miyata J, Carrillo D, Malladi V, Rakheja D, Pedrosa I, Xu L, Kinch L, Brugarolas J. Germline and sporadic mTOR pathway mutations in low-grade oncocytic tumor of the kidney. Mod Pathol 2022; 35:333-343. [PMID: 34538873 PMCID: PMC9817016 DOI: 10.1038/s41379-021-00896-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 08/03/2021] [Accepted: 08/04/2021] [Indexed: 01/11/2023]
Abstract
Low-grade oncocytic tumor (LOT) of the kidney is a recently described entity with poorly understood pathogenesis. Using next-generation sequencing (NGS) and complementary approaches, we provide insight into its biology. We describe 22 LOT corresponding to 7 patients presenting with a median age of 75 years (range 63-86 years) and male to female ratio 2:5. All 22 tumors demonstrated prototypical microscopic features. Tumors were well-circumscribed and solid. They were composed of sheets of tumor cells in compact nests. Tumor cells had eosinophilic cytoplasm, round to oval nuclei (without nuclear membrane irregularities), focal subtle perinuclear halos, and occasional binucleation. Sharply delineated edematous stromal islands were often observed. Tumor cells were positive for PAX8, negative for CD117, and exhibited diffuse and strong cytokeratin-7 expression. Six patients presented with pT1 tumors. At a median follow-up of 29 months, four patients were alive without recurrence (three patients had died from unrelated causes). All tumors were originally classified as chromophobe renal cell carcinoma, eosinophilic variant (chRCC-eo). While none of the patients presented with known syndromic features, one patient with multiple bilateral LOTs was subsequently found to have a likely pathogenic germline TSC1 mutation. Somatic, likely activating, mutations in MTOR and RHEB were identified in all other evaluable LOTs. As assessed by phospho-S6 and phospho-4E-BP1, mTOR complex 1 (mTORC1) was activated across all cases but to different extent. MTOR mutant LOT exhibited lower levels of mTORC1 activation, possibly related to mTORC1 dimerization and the preservation of a wild-type MTOR copy (retained chromosome 1). Supporting its distinction from related entities, gene expression analyses showed that LOT clustered separately from classic chRCC, chRCC-eo, and RO. In summary, converging mTORC1 pathway mutations, mTORC1 complex activation, and a distinctive gene expression signature along with characteristic phenotypic features support LOT designation as a distinct entity with both syndromic and non-syndromic cases associated with an indolent course.
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Affiliation(s)
- Payal Kapur
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Ming Gao
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390,Department of Hematology-Oncology Division of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Hua Zhong
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390,Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Suneetha Chintalapati
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Midori Mitui
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Spencer Barnes
- Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Qinbo Zhou
- Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Jeffrey Miyata
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390,Department of Hematology-Oncology Division of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Deyssy Carrillo
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390,Department of Hematology-Oncology Division of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Venkat Malladi
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390,Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Dinesh Rakheja
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390,Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Ivan Pedrosa
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Lin Xu
- Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - Lisa Kinch
- Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - James Brugarolas
- Kidney Cancer Program at Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA. .,Department of Hematology-Oncology Division of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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128
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Kim WD, Wilson-Smillie MLDM, Thanabalasingam A, Lefrancois S, Cotman SL, Huber RJ. Autophagy in the Neuronal Ceroid Lipofuscinoses (Batten Disease). Front Cell Dev Biol 2022; 10:812728. [PMID: 35252181 PMCID: PMC8888908 DOI: 10.3389/fcell.2022.812728] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
The neuronal ceroid lipofuscinoses (NCLs), also referred to as Batten disease, are a family of neurodegenerative diseases that affect all age groups and ethnicities around the globe. At least a dozen NCL subtypes have been identified that are each linked to a mutation in a distinct ceroid lipofuscinosis neuronal (CLN) gene. Mutations in CLN genes cause the accumulation of autofluorescent lipoprotein aggregates, called ceroid lipofuscin, in neurons and other cell types outside the central nervous system. The mechanisms regulating the accumulation of this material are not entirely known. The CLN genes encode cytosolic, lysosomal, and integral membrane proteins that are associated with a variety of cellular processes, and accumulated evidence suggests they participate in shared or convergent biological pathways. Research across a variety of non-mammalian and mammalian model systems clearly supports an effect of CLN gene mutations on autophagy, suggesting that autophagy plays an essential role in the development and progression of the NCLs. In this review, we summarize research linking the autophagy pathway to the NCLs to guide future work that further elucidates the contribution of altered autophagy to NCL pathology.
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Affiliation(s)
- William D. Kim
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | | | - Aruban Thanabalasingam
- Environmental and Life Sciences Graduate Program, Trent University, Peterborough, ON, Canada
| | - Stephane Lefrancois
- Centre Armand-Frappier Santé Biotechnologie, Institut National de La Recherche Scientifique, Laval, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
- Centre D'Excellence en Recherche sur Les Maladies Orphelines–Fondation Courtois (CERMO-FC), Université Du Québec à Montréal (UQAM), Montréal, QC, Canada
| | - Susan L. Cotman
- Department of Neurology, Center for Genomic Medicine, Massachusetts General Hospital Research Institute, Harvard Medical School, Boston, MA, United States
| | - Robert J. Huber
- Department of Biology, Trent University, Peterborough, ON, Canada
- *Correspondence: Robert J. Huber,
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129
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Liu S, Yang Q, Dong B, Qi C, Yang T, Li M, He S, Liu B, Wu J. Gypenosides Attenuate Pulmonary Fibrosis by Inhibiting the AKT/mTOR/c-Myc Pathway. Front Pharmacol 2022; 12:806312. [PMID: 35095515 PMCID: PMC8795913 DOI: 10.3389/fphar.2021.806312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/20/2021] [Indexed: 12/29/2022] Open
Abstract
Gypenosides (Gyps), the major active constituents isolated from Gynostemma pentaphyllum, possess anti-inflammatory and antioxidant activities. Previous studies have demonstrated that Gyps displayed potent ameliorative effects on liver fibrosis and renal fibrosis. In this study, we found that Gyps significantly reduced the mortality of bleomycin-induced pulmonary fibrosis mice (40% mortality rate of mice in the model group versus 0% in the treatment group). Masson staining showed that Gyps could reduce the content of collagen in the lung tissue of pulmonary fibrosis mice Masson staining and immunohistochemistry demonstrated that the expression of the collagen gene α-SMA and fibrosis gene Col1 markedly decreased after Gyps treatment. The active mitosis of fibroblasts is one of the key processes in the pathogenesis of fibrotic diseases. RNA-seq showed that Gyps significantly inhibited mitosis and induced the G2/M phase cell cycle arrest. The mTOR/c-Myc axis plays an important role in the pathological process of pulmonary fibrosis. RNA-seq also demonstrated that Gyps inhibited the mTOR and c-Myc signaling in pulmonary fibrosis mice, which was further validated by Western blot and immunohistochemistry. AKT functions as an upstream molecule that regulates mTOR. Our western blot data showed that Gyps could suppress the activation of AKT. In conclusion, Gyps exerted anti-pulmonary fibrosis activity by inhibiting the AKT/mTOR/c-Myc pathway.
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Affiliation(s)
- Suqing Liu
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Qingqing Yang
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China.,Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Binbin Dong
- Department of Pediatrics, Huashan Hospital North, Fudan University, Shanghai, China
| | - Chunhui Qi
- Department of Respiratory Medicine, Qingpu District Traditional Chinese Medicine Hospital, Institute of Integrative Medicine, Fudan University, Shanghai, China
| | - Tao Yang
- Department of Cardiovascular Disease, Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ming Li
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Shan He
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China
| | - Baojun Liu
- Department of Integrative Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jinfeng Wu
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai, China
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130
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Cui M, Jiang W, Sheng J, Wu J, Zhang X. Rap_GAP Domain of TSC2 Contributes to Tumor Suppression Through mTOR Signaling in Human Hepatocellular Carcinoma. DNA Cell Biol 2022; 41:215-224. [PMID: 35143341 DOI: 10.1089/dna.2021.0769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is an aggressive disease with a high degree of tumor heterogeneity. Genetic lesions of mTOR-related genes, including TSC2 and hyperactivation of mTOR signaling, are common in HCC. However, the association of genetic alterations with hepatocarcinogenesis remains unclear. In this study, continuous truncating mutations occurred within or upstream of the TSC2 Rap_GAP domain in clinical HCC samples. To elucidate whether hyperactivation of mTOR signaling in HCC is caused by TSC2 truncating mutations, HCC cell models carrying the TSC2 deletion (CRISPR/Cas9) or the TSC2 truncating mutation (mutagenesis) were established. Our findings showed that either TSC2 deletion or TSC2 mutant could lead to TSC2 loss-of-function and hyperactivation of mTOR signaling. Furthermore, hyperactivation of mTOR signaling was relieved by rapamycin. Immunohistochemistry of clinical samples confirmed frequent TSC2 loss in HCC. Thus, our study revealed that genetic alterations cause TSC2 loss of function and result in the hyperactivation of mTOR, and high frequency of TSC2 truncating mutations around RAP_GAP domain may be one of the reasons for the hyperactivation of mTOR in HCC patients.
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Affiliation(s)
- Mengying Cui
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Jilin University, Changchun, P.R. China
| | - Weibo Jiang
- Department of Orthopedic, The Second Hospital of Jilin University, Changchun, P.R. China
| | - Jiyao Sheng
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Jilin University, Changchun, P.R. China
| | - Jiacheng Wu
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Jilin University, Changchun, P.R. China
| | - Xuewen Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Hospital of Jilin University, Changchun, P.R. China
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131
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Warren C, Pavletich NP. Structure of the human ATM kinase and mechanism of Nbs1 binding. eLife 2022; 11:74218. [PMID: 35076389 PMCID: PMC8828054 DOI: 10.7554/elife.74218] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 01/24/2022] [Indexed: 11/27/2022] Open
Abstract
DNA double-strand breaks (DSBs) can lead to mutations, chromosomal rearrangements, genome instability, and cancer. Central to the sensing of DSBs is the ATM (Ataxia-telangiectasia mutated) kinase, which belongs to the phosphatidylinositol 3-kinase-related protein kinase (PIKK) family. In response to DSBs, ATM is activated by the MRN (Mre11-Rad50-Nbs1) protein complex through a poorly understood process that also requires double-stranded DNA. Previous studies indicate that the FxF/Y motif of Nbs1 directly binds to ATM, and is required to retain active ATM at sites of DNA damage. Here, we report the 2.5 Å resolution cryo-EM structures of human ATM and its complex with the Nbs1 FxF/Y motif. In keeping with previous structures of ATM and its yeast homolog Tel1, the dimeric human ATM kinase adopts a symmetric, butterfly-shaped structure. The conformation of the ATM kinase domain is most similar to the inactive states of other PIKKs, suggesting that activation may involve an analogous realigning of the N and C lobes along with relieving the blockage of the substrate-binding site. We also show that the Nbs1 FxF/Y motif binds to a conserved hydrophobic cleft within the Spiral domain of ATM, suggesting an allosteric mechanism of activation. We evaluate the importance of these structural findings with mutagenesis and biochemical assays.
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Affiliation(s)
- Christopher Warren
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Nikola P Pavletich
- Memorial Sloan Kettering Cancer Center, Howard Hughes Medical Institute, New York, United States
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132
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Poznyak AV, Sukhorukov VN, Zhuravlev A, Orekhov NA, Kalmykov V, Orekhov AN. Modulating mTOR Signaling as a Promising Therapeutic Strategy for Atherosclerosis. Int J Mol Sci 2022; 23:ijms23031153. [PMID: 35163076 PMCID: PMC8835022 DOI: 10.3390/ijms23031153] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 12/14/2022] Open
Abstract
For more than a decade, atherosclerosis has been one of the leading causes of death in developed countries. The issue of treatment and prevention of the disease is especially acute. Despite the huge amount of basic and clinical research, a significant number of gaps remain in our understanding of the pathogenesis of atherosclerosis, and only their closure will bring us closer to understanding the causes of the disease at the cellular and molecular levels and, accordingly, to the development of an effective treatment. One of the seemingly well-studied elements of atherogenesis is the mTOR signaling pathway. However, more and more new details are still being clarified. Therapeutic strategies associated with rapamycin have worked well in a number of different diseases, and there is every reason to believe that targeting components of the mTOR pathway may pay off in atherosclerosis as well.
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Affiliation(s)
- Anastasia V. Poznyak
- Skolkovo Innovative Center, Institute for Atherosclerosis Research, Osennyaya Street 4-1-207, 121609 Moscow, Russia;
- Correspondence: (A.V.P.); (A.N.O.)
| | - Vasily N. Sukhorukov
- AP Avtsyn Research Institute of Human Morphology, 3 Tsyurupa Street, 117418 Moscow, Russia; (V.N.S.); (A.Z.); (V.K.)
- National Medical Research Center of Cardiology, Institute of Experimental Cardiology, 15A 3-rd Cherepkovskaya Street, 121552 Moscow, Russia
| | - Alexander Zhuravlev
- AP Avtsyn Research Institute of Human Morphology, 3 Tsyurupa Street, 117418 Moscow, Russia; (V.N.S.); (A.Z.); (V.K.)
| | - Nikolay A. Orekhov
- Skolkovo Innovative Center, Institute for Atherosclerosis Research, Osennyaya Street 4-1-207, 121609 Moscow, Russia;
| | - Vladislav Kalmykov
- AP Avtsyn Research Institute of Human Morphology, 3 Tsyurupa Street, 117418 Moscow, Russia; (V.N.S.); (A.Z.); (V.K.)
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, 125315 Moscow, Russia
| | - Alexander N. Orekhov
- Skolkovo Innovative Center, Institute for Atherosclerosis Research, Osennyaya Street 4-1-207, 121609 Moscow, Russia;
- AP Avtsyn Research Institute of Human Morphology, 3 Tsyurupa Street, 117418 Moscow, Russia; (V.N.S.); (A.Z.); (V.K.)
- Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, Russian Academy of Medical Sciences, 125315 Moscow, Russia
- Correspondence: (A.V.P.); (A.N.O.)
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Defective Cystinosin, Aberrant Autophagy−Endolysosome Pathways, and Storage Disease: Towards Assembling the Puzzle. Cells 2022; 11:cells11030326. [PMID: 35159136 PMCID: PMC8834619 DOI: 10.3390/cells11030326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/03/2022] [Accepted: 01/11/2022] [Indexed: 02/05/2023] Open
Abstract
Epithelial cells that form the kidney proximal tubule (PT) rely on an intertwined ecosystem of vesicular membrane trafficking pathways to ensure the reabsorption of essential nutrients—a key requisite for homeostasis. The endolysosome stands at the crossroads of this sophisticated network, internalizing molecules through endocytosis, sorting receptors and nutrient transporters, maintaining cellular quality control via autophagy, and toggling the balance between PT differentiation and cell proliferation. Dysregulation of such endolysosome-guided trafficking pathways might thus lead to a generalized dysfunction of PT cells, often causing chronic kidney disease and life-threatening complications. In this review, we highlight the biological functions of endolysosome-residing proteins from the perspectives of understanding—and potentially reversing—the pathophysiology of rare inherited diseases affecting the kidney PT. Using cystinosis as a paradigm of endolysosome disease causing PT dysfunction, we discuss how the endolysosome governs the homeostasis of specialized epithelial cells. This review also provides a critical analysis of the molecular mechanisms through which defects in autophagy pathways can contribute to PT dysfunction, and proposes potential interventions for affected tissues. These insights might ultimately accelerate the discovery and development of new therapeutics, not only for cystinosis, but also for other currently intractable endolysosome-related diseases, eventually transforming our ability to regulate homeostasis and health.
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Sebestyén A, Dankó T, Sztankovics D, Moldvai D, Raffay R, Cervi C, Krencz I, Zsiros V, Jeney A, Petővári G. The role of metabolic ecosystem in cancer progression — metabolic plasticity and mTOR hyperactivity in tumor tissues. Cancer Metastasis Rev 2022; 40:989-1033. [PMID: 35029792 PMCID: PMC8825419 DOI: 10.1007/s10555-021-10006-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/26/2021] [Indexed: 12/14/2022]
Abstract
Despite advancements in cancer management, tumor relapse and metastasis are associated with poor outcomes in many cancers. Over the past decade, oncogene-driven carcinogenesis, dysregulated cellular signaling networks, dynamic changes in the tissue microenvironment, epithelial-mesenchymal transitions, protein expression within regulatory pathways, and their part in tumor progression are described in several studies. However, the complexity of metabolic enzyme expression is considerably under evaluated. Alterations in cellular metabolism determine the individual phenotype and behavior of cells, which is a well-recognized hallmark of cancer progression, especially in the adaptation mechanisms underlying therapy resistance. In metabolic symbiosis, cells compete, communicate, and even feed each other, supervised by tumor cells. Metabolic reprogramming forms a unique fingerprint for each tumor tissue, depending on the cellular content and genetic, epigenetic, and microenvironmental alterations of the developing cancer. Based on its sensing and effector functions, the mechanistic target of rapamycin (mTOR) kinase is considered the master regulator of metabolic adaptation. Moreover, mTOR kinase hyperactivity is associated with poor prognosis in various tumor types. In situ metabolic phenotyping in recent studies highlights the importance of metabolic plasticity, mTOR hyperactivity, and their role in tumor progression. In this review, we update recent developments in metabolic phenotyping of the cancer ecosystem, metabolic symbiosis, and plasticity which could provide new research directions in tumor biology. In addition, we suggest pathomorphological and analytical studies relating to metabolic alterations, mTOR activity, and their associations which are necessary to improve understanding of tumor heterogeneity and expand the therapeutic management of cancer.
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135
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Kliche J, Ivarsson Y. Orchestrating serine/threonine phosphorylation and elucidating downstream effects by short linear motifs. Biochem J 2022; 479:1-22. [PMID: 34989786 PMCID: PMC8786283 DOI: 10.1042/bcj20200714] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 12/13/2022]
Abstract
Cellular function is based on protein-protein interactions. A large proportion of these interactions involves the binding of short linear motifs (SLiMs) by folded globular domains. These interactions are regulated by post-translational modifications, such as phosphorylation, that create and break motif binding sites or tune the affinity of the interactions. In addition, motif-based interactions are involved in targeting serine/threonine kinases and phosphatases to their substrate and contribute to the specificity of the enzymatic actions regulating which sites are phosphorylated. Here, we review how SLiM-based interactions assist in determining the specificity of serine/threonine kinases and phosphatases, and how phosphorylation, in turn, affects motif-based interactions. We provide examples of SLiM-based interactions that are turned on/off, or are tuned by serine/threonine phosphorylation and exemplify how this affects SLiM-based protein complex formation.
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Affiliation(s)
- Johanna Kliche
- Department of Chemistry – BMC, Uppsala University, Husargatan 3, Box 576 751 23 Uppsala, Sweden
| | - Ylva Ivarsson
- Department of Chemistry – BMC, Uppsala University, Husargatan 3, Box 576 751 23 Uppsala, Sweden
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136
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Autophosphorylation transforms DNA-PK from protecting to processing DNA ends. Mol Cell 2022; 82:177-189.e4. [PMID: 34936881 PMCID: PMC8916119 DOI: 10.1016/j.molcel.2021.11.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/18/2021] [Accepted: 11/23/2021] [Indexed: 01/09/2023]
Abstract
The DNA-dependent protein kinase (DNA-PK) initially protects broken DNA ends but then promotes their processing during non-homologous end joining (NHEJ). Before ligation by NHEJ, DNA hairpin ends generated during V(D)J recombination must be opened by the Artemis nuclease, together with autophosphorylated DNA-PK. Structures of DNA-PK bound to DNA before and after phosphorylation, and in complex with Artemis and a DNA hairpin, reveal an essential functional switch. When bound to open DNA ends in its protection mode, DNA-PK is inhibited for cis-autophosphorylation of the so-called ABCDE cluster but activated for phosphorylation of other targets. In contrast, DNA hairpin ends promote cis-autophosphorylation. Phosphorylation of four Thr residues in ABCDE leads to gross structural rearrangement of DNA-PK, widening the DNA binding groove for Artemis recruitment and hairpin cleavage. Meanwhile, Artemis locks DNA-PK into the kinase-inactive state. Kinase activity and autophosphorylation of DNA-PK are regulated by different DNA ends, feeding forward to coordinate NHEJ events.
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137
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Molecular mechanisms of dietary restriction promoting health and longevity. Nat Rev Mol Cell Biol 2022; 23:56-73. [PMID: 34518687 PMCID: PMC8692439 DOI: 10.1038/s41580-021-00411-4] [Citation(s) in RCA: 243] [Impact Index Per Article: 121.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2021] [Indexed: 02/08/2023]
Abstract
Dietary restriction with adequate nutrition is the gold standard for delaying ageing and extending healthspan and lifespan in diverse species, including rodents and non-human primates. In this Review, we discuss the effects of dietary restriction in these mammalian model organisms and discuss accumulating data that suggest that dietary restriction results in many of the same physiological, metabolic and molecular changes responsible for the prevention of multiple ageing-associated diseases in humans. We further discuss how different forms of fasting, protein restriction and specific reductions in the levels of essential amino acids such as methionine and the branched-chain amino acids selectively impact the activity of AKT, FOXO, mTOR, nicotinamide adenine dinucleotide (NAD+), AMP-activated protein kinase (AMPK) and fibroblast growth factor 21 (FGF21), which are key components of some of the most important nutrient-sensing geroprotective signalling pathways that promote healthy longevity.
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138
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Zhang T, Wang Y, Yu H, Zhang T, Guo L, Xu J, Wei X, Wang N, Wu Y, Wang X, Huang L. PGK1 represses autophagy-mediated cell death to promote the proliferation of liver cancer cells by phosphorylating PRAS40. Cell Death Dis 2022; 13:68. [PMID: 35058442 PMCID: PMC8776853 DOI: 10.1038/s41419-022-04499-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 12/07/2021] [Accepted: 12/30/2021] [Indexed: 01/18/2023]
Abstract
Autophagy predominantly promotes cell survival by recycling cell components, while it kills cells in specific contexts. Cell death related to autophagy plays important roles in multiple physiological and pathological situations including tumorigenesis, and the mechanism needs to be defined further. PRAS40 was found to be crucial in various cancers, and phosphorylation was reported to be involved in autophagy inhibition in monocytes. However, the detailed role of PRAS40 in autophagy and the relationship to tumorigenesis remain largely unknown. Herein we screened the binding partners of PRAS40, and found that PRAS40 interacted with Phosphoglycerate kinase 1 (PGK1). PGK1 phosphorylated PRAS40 at Threonine 246, which could be inhibited by blocking the interaction. Both in vitro and in vivo results revealed that PRAS40 mediated PGK1-induced cell growth. By tracing the mechanism, we found that PGK1 suppressed autophagy-mediated cell death, in which PRAS40 was crucial. Thus PGK1 phosphorylates PRAS40 to repress autophagy-mediated cell death under normoxia, promoting cellular proliferation. The binding of PGK1 to PRAS40 was transferred to Beclin1 under hypoxia, resulting in the increase of Beclin1 phosphorylation. These results suggest a novel model of tumorigenesis, in which PGK1 switches between repressing autophagy-mediated cell death via PRAS40 and inducing autophagy through Beclin1 according to the environmental oxygen level. Our study is anticipated to be able to offer novel insights in understanding PGK1/PRAS40 signaling hyperactivated cancers.
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139
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Jhanwar-Uniyal M, Dominguez JF, Mohan AL, Tobias ME, Gandhi CD. Disentangling the signaling pathways of mTOR complexes, mTORC1 and mTORC2, as a therapeutic target in glioblastoma. Adv Biol Regul 2021; 83:100854. [PMID: 34996736 DOI: 10.1016/j.jbior.2021.100854] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/03/2021] [Indexed: 12/13/2022]
Abstract
Aberrant signaling of mechanistic target of rapamycin (mTOR' aka mammalian target of rapamycin) is shown to be linked to tumorigenesis of numerous malignancies including glioblastoma (GB). Glioblastoma mTOR is a serine threonine kinase that functions by forming two multiprotein complexes. There complexes are named mTORC1 and mTORC2 and downstream activated substrate execute cellular and metabolic functions. This signaling cascade of PI3K/AKT/mTOR is often upregulated due to frequent loss of the tumor suppressor PTEN, a phosphatase that functions antagonistically to PI3K. mTOR regulates cell growth, motility, and metabolism by forming two multiprotein complexes, mTORC1 and mTORC2, which are composed of special binding partners. These complexes are sensitive to distinct stimuli. mTORC1 is sensitive to nutrients and mTORC2 is regulated via PI3K and growth factor signaling. Since rapamycin and it's analogue are less effective in treatment of GB, we used novel ATP-competitive dual inhibitors of mTORC1 and mTORC2, namely, Torin1, Torin2, and XL388. Torin2 caused a concentration dependent pharmacodynamic effects on inhibition of phosphorylation of the mTORC1 substrates S6KSer235/236 and 4E-BP1Thr37/46 as well as the mTORC2 substrate AKTSer473 resulting in suppression of tumor cell proliferation and migration. Torin1 showed similar effects only at higher doses. Another small molecule compound, XL388 suppressed cell proliferation at a higher dose but failed to inhibit cell migration. Torin1 suppressed phosphorylation of PRAS40Thr246, however Torin2 completely abolished it. XL388 treatment inhibited the phosphorylation of PRAS40Thr246 at higher doses only. These findings underscore the use of novel compounds in treatment of cancer. In addition, formulation of third generation mTOR inhibitor "Rapalink-1" may provide new aspects to target mTOR pathways. Numerous inhibitors are currently being used in clinical trials that are aimed to target activated mTOR pathways.
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Affiliation(s)
- Meena Jhanwar-Uniyal
- Department of Neurosurgery, Westchester Medical Center, New York Medical College, Valhalla, NY, 10595, USA.
| | - Jose F Dominguez
- Department of Neurosurgery, Westchester Medical Center, New York Medical College, Valhalla, NY, 10595, USA
| | - Avinash L Mohan
- Department of Neurosurgery, Westchester Medical Center, New York Medical College, Valhalla, NY, 10595, USA
| | - Michael E Tobias
- Department of Neurosurgery, Westchester Medical Center, New York Medical College, Valhalla, NY, 10595, USA
| | - Chirag D Gandhi
- Department of Neurosurgery, Westchester Medical Center, New York Medical College, Valhalla, NY, 10595, USA
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140
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Structure of the Human TELO2-TTI1-TTI2 Complex. J Mol Biol 2021; 434:167370. [PMID: 34838521 DOI: 10.1016/j.jmb.2021.167370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 11/21/2022]
Abstract
Phosphatidylinositol 3-kinase-related protein kinases (PIKKs) play critical roles in various metabolic pathways related to cell proliferation and survival. The TELO2-TTI1-TTI2 (TTT) complex has been proposed to recognize newly synthesized PIKKs and to deliver them to the R2TP complex (RUVBL1-RUVBL2-RPAP3-PIH1D1) and the heat shock protein 90 chaperone, thereby supporting their folding and assembly. Here, we determined the cryo-EM structure of the TTT complex at an average resolution of 4.2 Å. We describe the full-length structures of TTI1 and TELO2, and a partial structure of TTI2. All three proteins form elongated helical repeat structures. TTI1 provides a platform on which TELO2 and TTI2 bind to its central region and C-terminal end, respectively. The TELO2 C-terminal domain (CTD) is required for the interaction with TTI1 and recruitment of Ataxia-telangiectasia mutated (ATM). The N- and C-terminal segments of TTI1 recognize the FRAP-ATM-TRRAP (FAT) domain and the N-terminal HEAT repeats of ATM, respectively. The TELO2 CTD and TTI1 N- and C-terminal segments are required for cell survival in response to ionizing radiation.
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141
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Hu L, Chen F, Wu C, Wang J, Chen SS, Li XR, Wang J, Wu L, Ding JP, Wang JC, Huang C, Zheng H, Rao Y, Sun Y, Chang Z, Deng W, Luo C, Chin YE. Rapamycin recruits SIRT2 for FKBP12 deacetylation during mTOR activity modulation in innate immunity. iScience 2021; 24:103177. [PMID: 34712915 PMCID: PMC8529501 DOI: 10.1016/j.isci.2021.103177] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/17/2021] [Accepted: 09/23/2021] [Indexed: 12/29/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) is a serine-threonine kinase involved in cellular innate immunity, metabolism, and senescence. FK506-binding protein 12 (FKBP12) inhibits mTOR kinase activity via direct association. The FKBP12-mTOR association can be strengthened by the immunosuppressant rapamycin, but the underlying mechanism remains elusive. We show here that the FKBP12-mTOR association is tightly regulated by an acetylation–deacetylation cycle. FKBP12 is acetylated on the lysine cluster (K45/K48/K53) by CREB-binding protein (CBP) in mammalian cells in response to nutrient treatment. Acetyl-FKBP12 associates with CBP acetylated Rheb. Rapamycin recruits SIRT2 with a high affinity for FKBP12 association and deacetylation. SIRT2-deacetylated FKBP12 then switches its association from Rheb to mTOR. Nutrient-activated mTOR phosphorylates IRF3S386 for the antiviral response. In contrast, rapamycin strengthening FKBP12-mTOR association blocks mTOR antiviral activity by recruiting SIRT2 to deacetylate FKBP12. Hence, on/off mTOR activity in response to environmental nutrients relies on FKBP12 acetylation and deacetylation status in mammalian cells. FKBP12-mTOR association is tightly regulated by an acetylation–deacetylation cycle SIRT2 is responsible for FKBP12 deacetylation Acetylation of Rheb is indispensable to mTOR activation mTOR phosphorylates IRF3 S386 for type-I interferon gene expression
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Affiliation(s)
- Lin Hu
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Fuxian Chen
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Chao Wu
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Jun Wang
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Si-Si Chen
- Institute of Biochemistry and Cell Biology and Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Xiang-Rong Li
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Jing Wang
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Linpeng Wu
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Jian-Ping Ding
- Institute of Biochemistry and Cell Biology and Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Jian-Chuan Wang
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Chao Huang
- Institute of Biochemistry and Cell Biology and Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Hui Zheng
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Yu Rao
- Laboratory of Membrane Biology, School of Medicine and School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Yu Sun
- Institute of Biochemistry and Cell Biology and Institute of Nutrition and Health Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
| | - Zhijie Chang
- Laboratory of Membrane Biology, School of Medicine and School of Pharmaceutical Sciences, Tsinghua University, Beijing 100084, China
| | - Wei Deng
- Hematology center, cyrus Tang medical institute, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Cheng Luo
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Y Eugene Chin
- Institutes of Biological and Medical Sciences, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
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Rehbein U, Prentzell MT, Cadena Sandoval M, Heberle AM, Henske EP, Opitz CA, Thedieck K. The TSC Complex-mTORC1 Axis: From Lysosomes to Stress Granules and Back. Front Cell Dev Biol 2021; 9:751892. [PMID: 34778262 PMCID: PMC8586448 DOI: 10.3389/fcell.2021.751892] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/05/2021] [Indexed: 12/14/2022] Open
Abstract
The tuberous sclerosis protein complex (TSC complex) is a key integrator of metabolic signals and cellular stress. In response to nutrient shortage and stresses, the TSC complex inhibits the mechanistic target of rapamycin complex 1 (mTORC1) at the lysosomes. mTORC1 is also inhibited by stress granules (SGs), RNA-protein assemblies that dissociate mTORC1. The mechanisms of lysosome and SG recruitment of mTORC1 are well studied. In contrast, molecular details on lysosomal recruitment of the TSC complex have emerged only recently. The TSC complex subunit 1 (TSC1) binds lysosomes via phosphatidylinositol-3,5-bisphosphate [PI(3,5)P2]. The SG assembly factors 1 and 2 (G3BP1/2) have an unexpected lysosomal function in recruiting TSC2 when SGs are absent. In addition, high density lipoprotein binding protein (HDLBP, also named Vigilin) recruits TSC2 to SGs under stress. In this mini-review, we integrate the molecular mechanisms of lysosome and SG recruitment of the TSC complex. We discuss their interplay in the context of cell proliferation and migration in cancer and in the clinical manifestations of tuberous sclerosis complex disease (TSC) and lymphangioleiomyomatosis (LAM).
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Affiliation(s)
- Ulrike Rehbein
- Laboratory for Metabolic Signaling, Institute of Biochemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria
| | - Mirja Tamara Prentzell
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Bioscience, Heidelberg University, Heidelberg, Germany
| | - Marti Cadena Sandoval
- Laboratory for Metabolic Signaling, Institute of Biochemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria.,Section Systems Medicine of Metabolism and Signaling, Department of Pediatrics, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Alexander Martin Heberle
- Laboratory for Metabolic Signaling, Institute of Biochemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria.,Section Systems Medicine of Metabolism and Signaling, Department of Pediatrics, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Elizabeth P Henske
- Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Christiane A Opitz
- Brain Cancer Metabolism Group, German Consortium of Translational Cancer Research (DKTK) & German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Neurology, National Center for Tumor Diseases, University Hospital Heidelberg, Heidelberg, Germany
| | - Kathrin Thedieck
- Laboratory for Metabolic Signaling, Institute of Biochemistry, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Innsbruck, Austria.,Section Systems Medicine of Metabolism and Signaling, Department of Pediatrics, University of Groningen and University Medical Center Groningen, Groningen, Netherlands.,Department for Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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143
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Regner MJ, Wisniewska K, Garcia-Recio S, Thennavan A, Mendez-Giraldez R, Malladi VS, Hawkins G, Parker JS, Perou CM, Bae-Jump VL, Franco HL. A multi-omic single-cell landscape of human gynecologic malignancies. Mol Cell 2021; 81:4924-4941.e10. [PMID: 34739872 PMCID: PMC8642316 DOI: 10.1016/j.molcel.2021.10.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 08/05/2021] [Accepted: 10/13/2021] [Indexed: 01/05/2023]
Abstract
Deconvolution of regulatory mechanisms that drive transcriptional programs in cancer cells is key to understanding tumor biology. Herein, we present matched transcriptome (scRNA-seq) and chromatin accessibility (scATAC-seq) profiles at single-cell resolution from human ovarian and endometrial tumors processed immediately following surgical resection. This dataset reveals the complex cellular heterogeneity of these tumors and enabled us to quantitatively link variation in chromatin accessibility to gene expression. We show that malignant cells acquire previously unannotated regulatory elements to drive hallmark cancer pathways. Moreover, malignant cells from within the same patients show substantial variation in chromatin accessibility linked to transcriptional output, highlighting the importance of intratumoral heterogeneity. Finally, we infer the malignant cell type-specific activity of transcription factors. By defining the regulatory logic of cancer cells, this work reveals an important reliance on oncogenic regulatory elements and highlights the ability of matched scRNA-seq/scATAC-seq to uncover clinically relevant mechanisms of tumorigenesis in gynecologic cancers.
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Affiliation(s)
- Matthew J. Regner
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Bioinformatics and Computational Biology Graduate Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,These authors contributed equally
| | - Kamila Wisniewska
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,These authors contributed equally
| | - Susana Garcia-Recio
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Aatish Thennavan
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Oral and Craniofacial Biomedicine Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Raul Mendez-Giraldez
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Venkat S. Malladi
- Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Gabrielle Hawkins
- Division of Gynecology Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Joel S. Parker
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Charles M. Perou
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Victoria L. Bae-Jump
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Division of Gynecology Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Hector L. Franco
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Bioinformatics and Computational Biology Graduate Program, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Lead contact.,Correspondence:
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144
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Zhang S, Wang H, Melick CH, Jeong MH, Curukovic A, Tiwary S, Lama-Sherpa TD, Meng D, Servage KA, James NG, Jewell JL. AKAP13 couples GPCR signaling to mTORC1 inhibition. PLoS Genet 2021; 17:e1009832. [PMID: 34673774 PMCID: PMC8570464 DOI: 10.1371/journal.pgen.1009832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 11/05/2021] [Accepted: 09/21/2021] [Indexed: 01/14/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) senses multiple stimuli to regulate anabolic and catabolic processes. mTORC1 is typically hyperactivated in multiple human diseases such as cancer and type 2 diabetes. Extensive research has focused on signaling pathways that can activate mTORC1 such as growth factors and amino acids. However, less is known about signaling cues that can directly inhibit mTORC1 activity. Here, we identify A-kinase anchoring protein 13 (AKAP13) as an mTORC1 binding protein, and a crucial regulator of mTORC1 inhibition by G-protein coupled receptor (GPCR) signaling. GPCRs paired to Gαs proteins increase cyclic adenosine 3’5’ monophosphate (cAMP) to activate protein kinase A (PKA). Mechanistically, AKAP13 acts as a scaffold for PKA and mTORC1, where PKA inhibits mTORC1 through the phosphorylation of Raptor on Ser 791. Importantly, AKAP13 mediates mTORC1-induced cell proliferation, cell size, and colony formation. AKAP13 expression correlates with mTORC1 activation and overall lung adenocarcinoma patient survival, as well as lung cancer tumor growth in vivo. Our study identifies AKAP13 as an important player in mTORC1 inhibition by GPCRs, and targeting this pathway may be beneficial for human diseases with hyperactivated mTORC1. The mammalian target of rapamycin complex 1 (mTORC1) can sense multiple upstream stimuli to regulate cell growth and metabolism. Increased mTORC1 activation results in many human diseases such as cancer. Small molecules like rapamycin that target and inhibit mTORC1, are available in the clinic with limited success. Thus, decoding the mechanisms involved in mTORC1 regulation is crucial. Most of the research has focused on stimuli that activate mTORC1. Less is known about signaling pathways that can directly inhibit mTORC1 activity. G-protein coupled receptors (GPCRs) coupled to Gαs proteins signal to and potently inhibit mTORC1. In this study, we have identified AKAP13 to play a crucial role in mTORC1 inhibition by GPCR signaling. Importantly, GPCRs are the largest family of drug targets with many approved FDA compounds. Targeting this signaling pathway may be beneficial for human diseases with hyperactivated mTORC1.
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Affiliation(s)
- Shihai Zhang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Provincial Key Laboratory of Animal Nutrition Control, College of Animal Science, South China Agricultural University, Guangzhou, People’s Republic of China
| | - Huanyu Wang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Chase H. Melick
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Mi-Hyeon Jeong
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Adna Curukovic
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Shweta Tiwary
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Tshering D. Lama-Sherpa
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Delong Meng
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Kelly A. Servage
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Nicholas G. James
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, United States of America
| | - Jenna L. Jewell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail:
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145
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Zhao J, Jia Y, Zhao W, Chen H, Zhang X, Ngo FY, Luo D, Song Y, Lao L, Rong J. Botanical Drug Puerarin Ameliorates Liposaccharide-Induced Depressive Behaviors in Mice via Inhibiting RagA/mTOR/p70S6K Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:7716201. [PMID: 34707778 PMCID: PMC8545548 DOI: 10.1155/2021/7716201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 09/27/2021] [Accepted: 09/29/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND The depressive symptom hallmarks the progression of the neurodegenerative diseases, especially Alzheimer's disease. Bacterial infection is related to inflammation and depression. The present project thereby examined whether botanical drug puerarin could attenuate liposaccharide- (LPS-) induced depressive behaviors in mice. METHODS Adult male C57BL/6N mice were sequentially treated with LPS and puerarin and evaluated for the depressive behaviors by tail suspension test and forced swim test. The brain tissues were profiled for the molecular targets of puerarin by next-generation RNA sequencing technique. Candidate targets were further verified in LPS-treated mice, neural stem cells, and highly differentiated PC12 cell line. RESULTS Puerarin ameliorated LPS-induced depression in the mice. RNA sequencing profiles revealed that puerarin altered the expression of 16 genes while markedly downregulated Ras-related GTP-binding protein A (RagA) in LPS-treated mice. The effect of puerarin on RagA expression was confirmed by immunostaining, Western blot, and quantitative real-time PCR (qRT-PCR). Biochemical studies showed that puerarin inhibited RagA/mTOR/p70S6K pathway, attenuated the accumulation of mTORC1 in close proximity to lysosome, and reduced the production of proinflammatory cytokines. CONCLUSIONS Botanical drug puerarin attenuated inflammation and depressive behaviors in LPS-challenged mice by inhibiting RagA/mTOR/p70S6K pathways. Puerarin may be a lead compound for the new antidepressant drugs.
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Affiliation(s)
- Jia Zhao
- Department of Chinese Medicine, The University of Hong Kong Shenzhen Hospital, Shenzhen, China
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
- Zhu Nansun's Workstation, School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
- Yu Jin's Workstation, School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Yizhen Jia
- Department of Chinese Medicine, The University of Hong Kong Shenzhen Hospital, Shenzhen, China
| | - Wei Zhao
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Huixin Chen
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Xiuying Zhang
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Fung Yin Ngo
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Dan Luo
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Youqiang Song
- School of Biomedical Science, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong, China
| | - Lixing Lao
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
| | - Jianhui Rong
- School of Chinese Medicine, The University of Hong Kong, 10 Sassoon Road, Pokfulam, Hong Kong, China
- The University of Hong Kong Shenzhen Institute of Research and Innovation (HKU-SIRI), Shenzhen, China
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146
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Shams R, Ito Y, Miyatake H. Mapping of mTOR drug targets: Featured platforms for anti-cancer drug discovery. Pharmacol Ther 2021; 232:108012. [PMID: 34624427 DOI: 10.1016/j.pharmthera.2021.108012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/25/2021] [Accepted: 09/28/2021] [Indexed: 12/12/2022]
Abstract
The mammalian/mechanistic target of rapamycin (mTOR) is a regulatory protein kinase involved in cell growth and proliferation. mTOR is usually assembled in two different complexes with different regulatory mechanisms, mTOR complex 1 (mTORC1) and mTORC2, which are involved in different functions such as cell proliferation and cytoskeleton assembly, respectively. In cancer cells, mTOR is hyperactivated in response to metabolic alterations and/or oncogenic signals to overcome the stressful microenvironments. Therefore, recent research progress for mTOR inhibition involves a variety of compounds that have been developed to disturb the metabolic processes of cancer cells through mTOR inhibition. In addition to competitive or allosteric inhibition, a new inhibition strategy that emerged mTOR complexes destabilization has recently been a concern. Here, we review the history of mTOR and its inhibition, along with the timeline of the mTOR inhibitors. We also introduce prospective drug targets to inhibit mTOR by disrupting the complexation of the components with peptides and small molecules.
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Affiliation(s)
- Raef Shams
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, RIKEN, Wako, Saitama 351-0198, Japan; Department of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan.
| | - Yoshihiro Ito
- Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, RIKEN, Wako, Saitama 351-0198, Japan; Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, RIKEN, Wako, Saitama 351-0198, Japan
| | - Hideyuki Miyatake
- Department of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan; Nano Medical Engineering Laboratory, RIKEN Cluster for Pioneering Research, RIKEN, Wako, Saitama 351-0198, Japan.
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147
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Hatakeyama R. Pib2 as an Emerging Master Regulator of Yeast TORC1. Biomolecules 2021; 11:biom11101489. [PMID: 34680122 PMCID: PMC8533233 DOI: 10.3390/biom11101489] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/05/2021] [Accepted: 10/07/2021] [Indexed: 12/18/2022] Open
Abstract
Cell growth is dynamically regulated in response to external cues such as nutrient availability, growth factor signals, and stresses. Central to this adaptation process is the Target of Rapamycin Complex 1 (TORC1), an evolutionarily conserved kinase complex that fine-tunes an enormous number of cellular events. How upstream signals are sensed and transmitted to TORC1 has been intensively studied in major model organisms including the budding yeast Saccharomyces cerevisiae. This field recently saw a breakthrough: the identification of yeast phosphatidylInositol(3)-phosphate binding protein 2 (Pib2) protein as a critical regulator of TORC1. Although the study of Pib2 is still in its early days, multiple groups have provided important mechanistic insights on how Pib2 relays nutrient signals to TORC1. There remain, on the other hand, significant gaps in our knowledge and mysteries that warrant further investigations. This is the first dedicated review on Pib2 that summarizes major findings and outstanding questions around this emerging key player in cell growth regulation.
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Affiliation(s)
- Riko Hatakeyama
- Institute of Medical Sciences, School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
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148
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Morozumi Y, Hishinuma A, Furusawa S, Sofyantoro F, Tatebe H, Shiozaki K. Fission yeast TOR complex 1 phosphorylates Psk1 through an evolutionarily conserved interaction mediated by the TOS motif. J Cell Sci 2021; 134:272450. [PMID: 34499159 PMCID: PMC8542387 DOI: 10.1242/jcs.258865] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/03/2021] [Indexed: 12/28/2022] Open
Abstract
TOR complex 1 (TORC1) is a multi-subunit protein kinase complex that controls cellular growth in response to environmental cues. The regulatory subunits of mammalian TORC1 (mTORC1) include RAPTOR (also known as RPTOR), which recruits mTORC1 substrates, such as S6K1 (also known as RPS6KB1) and 4EBP1 (EIF4EBP1), by interacting with their TOR signaling (TOS) motif. Despite the evolutionary conservation of TORC1, no TOS motif has been described in lower eukaryotes. In the present study, we show that the fission yeast S6 kinase Psk1 contains a TOS motif that interacts with Mip1, a RAPTOR ortholog. The TOS motif in Psk1 resembles those in mammals, including the conserved phenylalanine and aspartic acid residues essential for the Mip1 interaction and TORC1-dependent phosphorylation of Psk1. The binding of the TOS motif to Mip1 is dependent on Mip1 Tyr-533, whose equivalent in RAPTOR is known to interact with the TOS motif in their co-crystals. Furthermore, we utilized the mip1-Y533A mutation to screen the known TORC1 substrates in fission yeast and successfully identified Atg13 as a novel TOS-motif-containing substrate. These results strongly suggest that the TOS motif represents an evolutionarily conserved mechanism of the substrate recognition by TORC1. Summary: By analyzing S6 kinase in fission yeast, we have demonstrated that the TOR signaling (TOS) motif-mediated substrate recognition by TOR complex 1 is conserved from yeast to humans.
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Affiliation(s)
- Yuichi Morozumi
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Ai Hishinuma
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.,Tohoku Agricultural Research Center, National Agriculture and Food Research Organization, Daisen, Akita 019-2112, Japan
| | - Suguru Furusawa
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Fajar Sofyantoro
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.,Department of Animal Physiology, Faculty of Biology, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
| | - Hisashi Tatebe
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Kazuhiro Shiozaki
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.,Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
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149
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Yang G, Francis D, Krycer JR, Larance M, Zhang Z, Novotny CJ, Diaz-Vegas A, Shokat KM, James DE. Dissecting the biology of mTORC1 beyond rapamycin. Sci Signal 2021; 14:eabe0161. [PMID: 34546793 DOI: 10.1126/scisignal.abe0161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Guang Yang
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Deanne Francis
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - James R Krycer
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Mark Larance
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Ziyang Zhang
- Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, 600 16th Street, San Francisco, CA 94143, USA
| | - Chris J Novotny
- Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, 600 16th Street, San Francisco, CA 94143, USA
| | - Alexis Diaz-Vegas
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia
| | - Kevan M Shokat
- Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, 600 16th Street, San Francisco, CA 94143, USA
| | - David E James
- University of Sydney, School of life and Environmental Sciences, Charles Perkins Centre, Sydney, New South Wales 2006, Australia.,University of Sydney, Sydney Medical School, Sydney, New South Wales 2006, Australia
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150
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Wälchli M, Berneiser K, Mangia F, Imseng S, Craigie LM, Stuttfeld E, Hall MN, Maier T. Regulation of human mTOR complexes by DEPTOR. eLife 2021; 10:e70871. [PMID: 34519268 PMCID: PMC8439649 DOI: 10.7554/elife.70871] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/31/2021] [Indexed: 11/30/2022] Open
Abstract
The vertebrate-specific DEP domain-containing mTOR interacting protein (DEPTOR), an oncoprotein or tumor suppressor, has important roles in metabolism, immunity, and cancer. It is the only protein that binds and regulates both complexes of mammalian target of rapamycin (mTOR), a central regulator of cell growth. Biochemical analysis and cryo-EM reconstructions of DEPTOR bound to human mTOR complex 1 (mTORC1) and mTORC2 reveal that both structured regions of DEPTOR, the PDZ domain and the DEP domain tandem (DEPt), are involved in mTOR interaction. The PDZ domain binds tightly with mildly activating effect, but then acts as an anchor for DEPt association that allosterically suppresses mTOR activation. The binding interfaces of the PDZ domain and DEPt also support further regulation by other signaling pathways. A separate, substrate-like mode of interaction for DEPTOR phosphorylation by mTOR complexes rationalizes inhibition of non-stimulated mTOR activity at higher DEPTOR concentrations. The multifaceted interplay between DEPTOR and mTOR provides a basis for understanding the divergent roles of DEPTOR in physiology and opens new routes for targeting the mTOR-DEPTOR interaction in disease.
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Affiliation(s)
| | | | | | | | | | | | | | - Timm Maier
- Biozentrum, University of BaselBaselSwitzerland
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