1
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Leitl KD, Sperl LE, Hagn F. Preferred inhibition of pro-apoptotic Bak by BclxL via a two-step mechanism. Cell Rep 2024; 43:114526. [PMID: 39046879 DOI: 10.1016/j.celrep.2024.114526] [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] [Received: 02/27/2024] [Revised: 06/14/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
Bak is a pore-forming Bcl2 protein that induces apoptosis at the outer mitochondrial membrane, which can either proceed via Bak oligomerization or be inhibited by anti-apoptotic Bcl2 proteins, such as BclxL. BclxL is very efficient in inhibiting Bak pore formation, but the mechanistic basis of this preferred interaction has remained enigmatic. Here, we identify Bakα1 as a second binding site for BclxL and show that it specifically interacts with the Bcl2-homology (BH)3 binding groove of BclxL. The affinity between BclxL and Bakα1 is weaker than with Bak-BH3, suggesting that Bakα1, being exposed early in the pore-forming trajectory, transiently captures BclxL, which subsequently transitions to the proximal BH3 site. Bak variants where the initial transient interaction with BclxL is modulated show a markedly altered response to BclxL inhibition. This work contributes to a better mechanistic understanding of the fine-tuned interactions between different players of the Bcl2 protein family.
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Affiliation(s)
- Kira D Leitl
- Bavarian NMR Center (BNMRZ), Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85747 Garching, Germany; Molecular Targets and Therapeutics Center (MTTC), Institute of Structural Biology, Helmholtz Munich, 85764 Neuherberg, Germany
| | - Laura E Sperl
- Bavarian NMR Center (BNMRZ), Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85747 Garching, Germany
| | - Franz Hagn
- Bavarian NMR Center (BNMRZ), Department of Bioscience, School of Natural Sciences, Technical University of Munich, 85747 Garching, Germany; Molecular Targets and Therapeutics Center (MTTC), Institute of Structural Biology, Helmholtz Munich, 85764 Neuherberg, Germany.
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2
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Subas Satish HP, Iyer S, Shi MX, Wong AW, Fischer KC, Wardak AZ, Lio D, Brouwer JM, Uren RT, Czabotar PE, Miller MS, Kluck RM. A novel inhibitory BAK antibody enables assessment of non-activated BAK in cancer cells. Cell Death Differ 2024; 31:711-721. [PMID: 38582955 PMCID: PMC11164899 DOI: 10.1038/s41418-024-01289-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 04/08/2024] Open
Abstract
BAX and BAK are pro-apoptotic members of the BCL2 family that are required to permeabilize the mitochondrial outer membrane. The proteins can adopt a non-activated monomeric conformation, or an activated conformation in which the exposed BH3 domain facilitates binding either to a prosurvival protein or to another activated BAK or BAX protein to promote pore formation. Certain cancer cells are proposed to have high levels of activated BAK sequestered by MCL1 or BCLXL, thus priming these cells to undergo apoptosis in response to BH3 mimetic compounds that target MCL1 or BCLXL. Here we report the first antibody, 14G6, that is specific for the non-activated BAK conformer. A crystal structure of 14G6 Fab bound to BAK revealed a binding site encompassing both the α1 helix and α5-α6 hinge regions of BAK, two sites involved in the unfolding of BAK during its activation. In mitochondrial experiments, 14G6 inhibited BAK unfolding triggered by three diverse BAK activators, supporting crucial roles for both α1 dissociation and separation of the core (α2-α5) and latch (α6-α9) regions in BAK activation. 14G6 bound the majority of BAK in several leukaemia cell lines, and binding decreased following treatment with BH3 mimetics, indicating only minor levels of constitutively activated BAK in those cells. In summary, 14G6 provides a new means of assessing BAK status in response to anti-cancer treatments.
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Affiliation(s)
- Hema Preethi Subas Satish
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Sweta Iyer
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Melissa X Shi
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Agnes W Wong
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Karla C Fischer
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ahmad Z Wardak
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Daisy Lio
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jason M Brouwer
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Rachel T Uren
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Michelle S Miller
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Ruth M Kluck
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia.
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3
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Miller MS, Cowan AD, Brouwer JM, Smyth ST, Peng L, Wardak AZ, Uren RT, Luo C, Roy MJ, Shah S, Tan Z, Reid GE, Colman PM, Czabotar PE. Sequence differences between BAX and BAK core domains manifest as differences in their interactions with lipids. FEBS J 2024; 291:2335-2353. [PMID: 38088212 DOI: 10.1111/febs.17031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/07/2023] [Accepted: 12/11/2023] [Indexed: 01/21/2024]
Abstract
The B-cell lymphoma 2 (BCL2) family members, BCL2-associated protein X (BAX) and BCL2 homologous antagonist killer (BAK), are required for programmed cell death via the mitochondrial pathway. When cells are stressed, damaged or redundant, the balance of power between the BCL2 family of proteins shifts towards BAX and BAK, allowing their transition from an inactive, monomeric state to a membrane-active oligomeric form that releases cytochrome c from the mitochondrial intermembrane space. That oligomeric state has an essential intermediate, a symmetric homodimer of BAX or BAK. Here we describe crystal structures of dimers of the core domain of BAX, comprising its helices α2-α5. These structures provide an atomic resolution description of the interactions that drive BAX homo-dimerisation and insights into potential interaction between core domain dimers and membrane lipids. The previously identified BAK lipid-interacting sites are not conserved with BAX and are likely to determine the differences between them in their interactions with lipids. We also describe structures of heterodimers of BAK/BAX core domains, yielding further insight into the differences in lipid binding between BAX and BAK.
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Affiliation(s)
- Michelle S Miller
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Angus D Cowan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Jason M Brouwer
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Sean T Smyth
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Liuyu Peng
- School of Chemistry, University of Melbourne, Parkville, Vic., Australia
| | - Ahmad Z Wardak
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Rachel T Uren
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Cindy Luo
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Michael J Roy
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Sayali Shah
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Ziwen Tan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Gavin E Reid
- School of Chemistry, University of Melbourne, Parkville, Vic., Australia
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, Vic., Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic., Australia
| | - Peter M Colman
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
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4
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Yuan Z, van Delft MF, Li MX, Sumardy F, Smith BJ, Huang DCS, Lessene G, Khakam Y, Jin R, He S, Smith NA, Birkinshaw RW, Czabotar PE, Dewson G. Key residues in the VDAC2-BAK complex can be targeted to modulate apoptosis. PLoS Biol 2024; 22:e3002617. [PMID: 38696533 PMCID: PMC11098506 DOI: 10.1371/journal.pbio.3002617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 05/16/2024] [Accepted: 04/05/2024] [Indexed: 05/04/2024] Open
Abstract
BAK and BAX execute intrinsic apoptosis by permeabilising the mitochondrial outer membrane. Their activity is regulated through interactions with pro-survival BCL-2 family proteins and with non-BCL-2 proteins including the mitochondrial channel protein VDAC2. VDAC2 is important for bringing both BAK and BAX to mitochondria where they execute their apoptotic function. Despite this important function in apoptosis, while interactions with pro-survival family members are well characterised and have culminated in the development of drugs that target these interfaces to induce cancer cell apoptosis, the interaction between BAK and VDAC2 remains largely undefined. Deep scanning mutagenesis coupled with cysteine linkage identified key residues in the interaction between BAK and VDAC2. Obstructive labelling of specific residues in the BH3 domain or hydrophobic groove of BAK disrupted this interaction. Conversely, mutating specific residues in a cytosol-exposed region of VDAC2 stabilised the interaction with BAK and inhibited BAK apoptotic activity. Thus, this VDAC2-BAK interaction site can potentially be targeted to either inhibit BAK-mediated apoptosis in scenarios where excessive apoptosis contributes to disease or to promote BAK-mediated apoptosis for cancer therapy.
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Affiliation(s)
- Zheng Yuan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Mark F. van Delft
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Mark Xiang Li
- Peter MacCallum Cancer Centre, Parkville, Melbourne, Australia
| | - Fransisca Sumardy
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
| | - Brian J. Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - David C. S. Huang
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Guillaume Lessene
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, Melbourne, Australia
| | - Yelena Khakam
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
| | - Ruitao Jin
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
- Research School of Biology, Australian National University, Canberra, Australia
| | - Sitong He
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Nicholas A. Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Richard W. Birkinshaw
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Peter E. Czabotar
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
| | - Grant Dewson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Australia
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5
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Lim D, Jeong DE, Shin HC, Choi JS, Seo J, Kim SJ, Ku B. Crystal structure of Bak bound to the BH3 domain of Bnip5, a noncanonical BH3 domain-containing protein. Proteins 2024; 92:44-51. [PMID: 37553948 DOI: 10.1002/prot.26568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/24/2023] [Accepted: 07/31/2023] [Indexed: 08/10/2023]
Abstract
The activation or inactivation of B-cell lymphoma-2 (Bcl-2) antagonist/killer (Bak) is critical for controlling mitochondrial outer membrane permeabilization-dependent apoptosis. Its pro-apoptotic activity is controlled by intermolecular interactions with the Bcl-2 homology 3 (BH3) domain, which is accommodated in the hydrophobic pocket of Bak. Bcl-2-interacting protein 5 (Bnip5) is a noncanonical BH3 domain-containing protein that interacts with Bak. Bnip5 is characterized by its controversial effects on the regulation of the pro-apoptotic activity of Bak. In the present study, we determined the crystal structure of Bak bound to Bnip5 BH3. The intermolecular association appeared to be typical at first glance, but we found that it is maintained by tight hydrophobic interactions together with hydrogen/ionic bonds, which accounts for their high binding affinity with a dissociation constant of 775 nM. Structural analysis of the complex showed that Bnip5 interacts with Bak in a manner similar to that of the Bak-activating pro-apoptotic factor peroxisomal testis-enriched protein 1, particularly in the destabilization of the intramolecular electrostatic network of Bak. Our structure is considered to reflect the initial point of drastic and consecutive conformational and stoichiometric changes in Bak induced by Bnip5 BH3, which helps in explaining the effects of Bnip5 in regulating Bak-mediated apoptosis.
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Affiliation(s)
- Dahwan Lim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Critical Diseases Diagnostics Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Department of Biochemistry, Chungnam National University, Daejeon, Republic of Korea
| | - Da Eun Jeong
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Critical Diseases Diagnostics Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Department of Biology, Chungnam National University, Daejeon, Republic of Korea
| | - Ho-Chul Shin
- Critical Diseases Diagnostics Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Joon Sig Choi
- Department of Biochemistry, Chungnam National University, Daejeon, Republic of Korea
| | - Jinho Seo
- Aging Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Seung Jun Kim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Critical Diseases Diagnostics Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Bonsu Ku
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
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6
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Cheng P, Hou Y, Bian M, Fang X, Liu Y, Rao Y, Cao S, Liu Y, Zhang S, Chen Y, Dong X, Liu Z. Parkin-mediated ubiquitination inhibits BAK apoptotic activity by blocking its canonical hydrophobic groove. Commun Biol 2023; 6:1260. [PMID: 38087033 PMCID: PMC10716173 DOI: 10.1038/s42003-023-05650-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
BAK permeabilizes the mitochondrial outer membrane, causing apoptosis. This apoptotic activity of BAK is stimulated by binding prodeath activators within its canonical hydrophobic groove. Parkin, an E3 ubiquitin (Ub) ligase, can ubiquitinate BAK, which inhibits BAK apoptotic activity. However, the molecular mechanism underlying the inhibition of ubiquitination remains structurally uncharacterized. Here, we utilize truncated and soluble BAK to construct a mimetic of K113-ubiquitinated BAK (disulfide-linked UbG76C ~ BAKK113C) and further present its NMR-derived structure model. The classical L8-I44-H68-V70 hydrophobic patch of the conjugated Ub subunit binds within the canonical hydrophobic groove of BAK. This Ub occludes the binding of prodeath BID activators in the groove and impairs BID-triggered BAK activation and membrane permeabilization. Reduced interaction between Ub and BAK subunits allows BID to activate K113-ubiquitinated BAK. These mechanistic insights suggest a nonsignaling function of Ub in that it directly antagonizes stimuli targeting Ub-modified proteins rather than by recruiting downstream partners for cellular messaging.
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Affiliation(s)
- Peng Cheng
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuzhu Hou
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Mingxing Bian
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xueru Fang
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yan Liu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuanfang Rao
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shuo Cao
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yanjun Liu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shuai Zhang
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yanke Chen
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Xu Dong
- Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China.
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan, 430074, China.
| | - Zhu Liu
- National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
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7
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Czabotar PE, Garcia-Saez AJ. Mechanisms of BCL-2 family proteins in mitochondrial apoptosis. Nat Rev Mol Cell Biol 2023; 24:732-748. [PMID: 37438560 DOI: 10.1038/s41580-023-00629-4] [Citation(s) in RCA: 81] [Impact Index Per Article: 81.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/14/2023]
Abstract
The proteins of the BCL-2 family are key regulators of mitochondrial apoptosis, acting as either promoters or inhibitors of cell death. The functional interplay and balance between the opposing BCL-2 family members control permeabilization of the outer mitochondrial membrane, leading to the release of activators of the caspase cascade into the cytosol and ultimately resulting in cell death. Despite considerable research, our knowledge about the mechanisms of the BCL-2 family of proteins remains insufficient, which complicates cell fate predictions and does not allow us to fully exploit these proteins as targets for drug discovery. Detailed understanding of the formation and molecular architecture of the apoptotic pore in the outer mitochondrial membrane remains a holy grail in the field, but new studies allow us to begin constructing a structural model of its arrangement. Recent literature has also revealed unexpected activities for several BCL-2 family members that challenge established concepts of how they regulate mitochondrial permeabilization. In this Review, we revisit the most important advances in the field and integrate them into a new structure-function-based classification of the BCL-2 family members that intends to provide a comprehensive model for BCL-2 action in apoptosis. We close this Review by discussing the potential of drugging the BCL-2 family in diseases characterized by aberrant apoptosis.
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Affiliation(s)
- Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia.
| | - Ana J Garcia-Saez
- Membrane Biophysics, Institute of Genetics, CECAD, University of Cologne, Cologne, Germany.
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8
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Lim D, Choe SH, Jin S, Lee S, Kim Y, Shin HC, Choi JS, Oh DB, Kim SJ, Seo J, Ku B. Structural basis for proapoptotic activation of Bak by the noncanonical BH3-only protein Pxt1. PLoS Biol 2023; 21:e3002156. [PMID: 37315086 DOI: 10.1371/journal.pbio.3002156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 05/10/2023] [Indexed: 06/16/2023] Open
Abstract
Bak is a critical executor of apoptosis belonging to the Bcl-2 protein family. Bak contains a hydrophobic groove where the BH3 domain of proapoptotic Bcl-2 family members can be accommodated, which initiates its activation. Once activated, Bak undergoes a conformational change to oligomerize, which leads to mitochondrial destabilization and the release of cytochrome c into the cytosol and eventual apoptotic cell death. In this study, we investigated the molecular aspects and functional consequences of the interaction between Bak and peroxisomal testis-specific 1 (Pxt1), a noncanonical BH3-only protein exclusively expressed in the testis. Together with various biochemical approaches, this interaction was verified and analyzed at the atomic level by determining the crystal structure of the Bak-Pxt1 BH3 complex. In-depth biochemical and cellular analyses demonstrated that Pxt1 functions as a Bak-activating proapoptotic factor, and its BH3 domain, which mediates direct intermolecular interaction with Bak, plays a critical role in triggering apoptosis. Therefore, this study provides a molecular basis for the Pxt1-mediated novel pathway for the activation of apoptosis and expands our understanding of the cell death signaling coordinated by diverse BH3 domain-containing proteins.
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Affiliation(s)
- Dahwan Lim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
- Critical Diseases Diagnostics Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
- Department of Biochemistry, Chungnam National University, Daejeon, Korea
| | - So-Hui Choe
- Aging Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Sein Jin
- Aging Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Seulgi Lee
- Department of Biochemistry, Chungnam National University, Daejeon, Korea
| | - Younjin Kim
- Department of Biochemistry, Chungnam National University, Daejeon, Korea
| | - Ho-Chul Shin
- Critical Diseases Diagnostics Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | - Joon Sig Choi
- Department of Biochemistry, Chungnam National University, Daejeon, Korea
| | - Doo-Byoung Oh
- Aging Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, Korea
| | - Seung Jun Kim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
- Critical Diseases Diagnostics Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
- Department of Proteome Structural Biology, KRIBB School of Bioscience, University of Science and Technology, Daejeon, Korea
| | - Jinho Seo
- Aging Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
- Department of Biosystems and Bioengineering, KRIBB School of Biotechnology, University of Science and Technology, Daejeon, Korea
| | - Bonsu Ku
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
- Department of Proteome Structural Biology, KRIBB School of Bioscience, University of Science and Technology, Daejeon, Korea
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9
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Aldossari RM, Ali A, Rehman MU, Rashid S, Ahmad SB. Computational Approaches for Identification of Potential Plant Bioactives as Novel G6PD Inhibitors Using Advanced Tools and Databases. Molecules 2023; 28:molecules28073018. [PMID: 37049781 PMCID: PMC10096328 DOI: 10.3390/molecules28073018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/31/2023] Open
Abstract
In glucose metabolism, the pentose phosphate pathway (PPP) is the major metabolic pathway that plays a crucial role in cancer growth and metastasis. Although it has been pointed out that blockade of the PPP is a promising approach against cancer, in the clinical setting, effective anti-PPP agents are still not available. Dysfunction of the G6PD enzyme in this pathway leads to cancer development as this enzyme possesses oncogenic activity. In the present study, an attempt was made to identify bioactive compounds that can be developed as potential G6PD inhibitors. In the present study, 11 natural compounds and a controlled drug were taken. The physicochemical and toxicity properties of the compounds were determined via ADMET and ProTox-II analysis. In the present study, the findings of docking studies revealed that staurosporine was the most effective compound with the highest binding energy of −9.2 kcal/mol when docked against G6PD. Homology modeling revealed that 97.56% of the residues were occupied in the Ramachandran-favored region. The modeled protein gave a quality Z-score of −10.13 by ProSA tool. iMODS server provided significant insights into the mobility, stability and flexibility of the G6PD protein that described the collective functional protein motion. In the present study, the physical and functional interactions between proteins were determined by STRING. CASTp server determined the topological and geometric properties of the G6PD protein. The findings of the present study revealed that staurosporine could be developed as a potential G6PD inhibitor; however, further in vivo and in vitro studies are needed for further validation of these results.
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Affiliation(s)
- Rana M. Aldossari
- Department of Pharmacology & Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, P.O. Box 173, Al-Kharj 11942, Saudi Arabia
| | - Aarif Ali
- Division of Veterinary Biochemistry, Faculty of Veterinary Science and Animal Husbandry, SKUAST-Kashmir, Alustang, Shuhama 190006, Jammu & Kashmir, India
| | - Muneeb U. Rehman
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Summya Rashid
- Department of Pharmacology & Toxicology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, P.O. Box 173, Al-Kharj 11942, Saudi Arabia
- Correspondence:
| | - Sheikh Bilal Ahmad
- Division of Veterinary Biochemistry, Faculty of Veterinary Science and Animal Husbandry, SKUAST-Kashmir, Alustang, Shuhama 190006, Jammu & Kashmir, India
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10
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Ma Q, Yu J, Zhang X, Wu X, Deng G. Wnt/β-catenin signaling pathway-a versatile player in apoptosis and autophagy. Biochimie 2023; 211:57-67. [PMID: 36907502 DOI: 10.1016/j.biochi.2023.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 02/24/2023] [Accepted: 03/09/2023] [Indexed: 03/13/2023]
Abstract
The Wnt/β-catenin signaling pathway is a highly conserved pathway that is involved in cell development, proliferation, differentiation, apoptosis and autophagy. Among these processes, apoptosis and autophagy occur physiologically during host defense and the maintenance of intracellular homeostasis. Mounting evidence suggests that the crosstalk between Wnt/β-catenin-regulated apoptosis and autophagy has broad functional significance in various diseases. Herein, we summarize the recent studies in understanding the role of the Wnt/β-catenin signaling pathway in apoptosis and autophagy, and draw the following conclusions: a) For apoptosis, the regulation of Wnt/β-catenin is generally positive. However, a small amount of evidence indicates the presence of a negatively regulated relationship between Wnt/β-catenin and apoptosis; b) Wnt/β-catenin influences the occurrence and development of autophagy by regulating autophagy-related factors, and these factors in turn affect Wnt/β-catenin pathway; c) Wnt/β-catenin always balances the molecular damage caused by the crosstalk between autophagy and apoptosis in a compensatory manner. Understanding the specific role of the Wnt/β-catenin signaling pathway during different stages of autophagy and apoptosis may provide new insights into the progression of related diseases regulated by the Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Qinmei Ma
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, NingXia, China; School of Life Science, Ningxia University, Yinchuan, NingXia, China.
| | - Jialin Yu
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, NingXia, China; School of Life Science, Ningxia University, Yinchuan, NingXia, China.
| | - Xu Zhang
- Institute of Medical Sciences, General Hospital of Ningxia Medical University, Yinchuan, NingXia, China.
| | - Xiaoling Wu
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, NingXia, China; School of Life Science, Ningxia University, Yinchuan, NingXia, China.
| | - Guangcun Deng
- Key Lab of Ministry of Education for Protection and Utilization of Special Biological Resources in Western China, Ningxia University, Yinchuan, NingXia, China; School of Life Science, Ningxia University, Yinchuan, NingXia, China.
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11
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Aguilar F, Yu S, Grant RA, Swanson S, Ghose D, Su BG, Sarosiek KA, Keating AE. Peptides from human BNIP5 and PXT1 and non-native binders of pro-apoptotic BAK can directly activate or inhibit BAK-mediated membrane permeabilization. Structure 2023; 31:265-281.e7. [PMID: 36706751 PMCID: PMC9992319 DOI: 10.1016/j.str.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/24/2022] [Accepted: 01/02/2023] [Indexed: 01/27/2023]
Abstract
Apoptosis is important for development and tissue homeostasis, and its dysregulation can lead to diseases, including cancer. As an apoptotic effector, BAK undergoes conformational changes that promote mitochondrial outer membrane disruption, leading to cell death. This is termed "activation" and can be induced by peptides from the human proteins BID, BIM, and PUMA. To identify additional peptides that can regulate BAK, we used computational protein design, yeast surface display screening, and structure-based energy scoring to identify 10 diverse new binders. We discovered peptides from the human proteins BNIP5 and PXT1 and three non-native peptides that activate BAK in liposome assays and induce cytochrome c release from mitochondria. Crystal structures and binding studies reveal a high degree of similarity among peptide activators and inhibitors, ruling out a simple function-determining property. Our results shed light on the vast peptide sequence space that can regulate BAK function and will guide the design of BAK-modulating tools and therapeutics.
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Affiliation(s)
- Fiona Aguilar
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Stacey Yu
- Laboratory of Systems Pharmacology, Harvard Program in Therapeutic Science, Department of Systems Biology, Harvard Medical School, Boston, MA, USA; Program in Molecular and Integrative Physiological Sciences Program, Harvard T.H. Chan School of Public Health, Boston, MA, USA; John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Robert A Grant
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sebastian Swanson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Dia Ghose
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Bonnie G Su
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kristopher A Sarosiek
- Laboratory of Systems Pharmacology, Harvard Program in Therapeutic Science, Department of Systems Biology, Harvard Medical School, Boston, MA, USA; Program in Molecular and Integrative Physiological Sciences Program, Harvard T.H. Chan School of Public Health, Boston, MA, USA; John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Amy E Keating
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
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12
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Moldoveanu T. Apoptotic mitochondrial poration by a growing list of pore-forming BCL-2 family proteins. Bioessays 2023; 45:e2200221. [PMID: 36650950 PMCID: PMC9975053 DOI: 10.1002/bies.202200221] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/31/2022] [Accepted: 01/02/2023] [Indexed: 01/19/2023]
Abstract
The pore-forming BCL-2 family proteins are effectors of mitochondrial poration in apoptosis initiation. Two atypical effectors-BOK and truncated BID (tBID)-join the canonical effectors BAK and BAX. Gene knockout revealed developmental phenotypes in the absence the effectors, supporting their roles in vivo. During apoptosis effectors are activated and change shape from dormant monomers to dynamic oligomers that associate with and permeabilize mitochondria. BID is activated by proteolysis, BOK accumulates on inhibition of its degradation by the E3 ligase gp78, while BAK and BAX undergo direct activation by BH3-only initiators, autoactivation, and crossactivation. Except tBID, effector oligomers on the mitochondria appear as arcs and rings in super-resolution microscopy images. The BH3-in-groove dimers of BAK and BAX, the tBID monomers, and uncharacterized BOK species are the putative building blocks of apoptotic pores. Effectors interact with lipids and bilayers but the mechanism of membrane poration remains elusive. I discuss effector-mediated mitochondrial poration.
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Affiliation(s)
- Tudor Moldoveanu
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences,Correspondence:
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13
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Sekar G, Singh G, Qin X, Guibao CD, Schwam B, Inde Z, Grace CR, Zhang W, Slavish PJ, Lin W, Chen T, Lee RE, Rankovic Z, Sarosiek K, Moldoveanu T. Small molecule SJ572946 activates BAK to initiate apoptosis. iScience 2022; 25:105064. [PMID: 36147946 PMCID: PMC9485059 DOI: 10.1016/j.isci.2022.105064] [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: 03/24/2022] [Revised: 06/29/2022] [Accepted: 08/30/2022] [Indexed: 01/11/2023] Open
Abstract
Poration of the outer mitochondrial membrane by the effector BCL-2 proteins BAK and BAX initiates apoptosis. BH3-only initiators BID and BIM trigger conformational changes in BAK and BAX transforming them from globular dormant proteins to oligomers of the apoptotic pores. Small molecules that can directly activate effectors are being sought for applications in cancer treatment. Here, we describe the small molecule SJ572946, discovered in a fragment-based screen that binds to the activation groove of BAK and selectively triggers BAK activation over that of BAX in liposome and mitochondrial permeabilization assays. SJ572946 independently kills BAK-expressing BCL2allKO HCT116 cells revealing on target cellular activity. In combination with apoptotic inducers and BH3 mimetics, SJ572946 kills experimental cancer cell lines. SJ572946 also cooperates with the endogenous BAK activator BID in activating a misfolded BAK mutant substantially impaired in activation. SJ572946 is a proof-of-concept tool for probing BAK-mediated apoptosis in preclinical cancer research.
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Affiliation(s)
- Giridhar Sekar
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Geetika Singh
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Children’s GMP, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Xingping Qin
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston,02115 MA, USA,Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, 02115 MA, USA,Laboratory of Systems Pharmacology, Harvard Medical School, Boston,02115 MA, USA
| | - Cristina D. Guibao
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Brittany Schwam
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Zintis Inde
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston,02115 MA, USA,Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, 02115 MA, USA,Laboratory of Systems Pharmacology, Harvard Medical School, Boston,02115 MA, USA
| | - Christy R. Grace
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Weixing Zhang
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - P. Jake Slavish
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Wenwei Lin
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Richard E. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Zoran Rankovic
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Kristopher Sarosiek
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston,02115 MA, USA,Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, 02115 MA, USA,Laboratory of Systems Pharmacology, Harvard Medical School, Boston,02115 MA, USA
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Roeck, AR 72205, USA,Corresponding author
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14
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Robin AY, Miller MS, Iyer S, Shi MX, Wardak AZ, Lio D, Smith NA, Smith BJ, Birkinshaw RW, Czabotar PE, Kluck RM, Colman PM. Structure of the BAK-activating antibody 7D10 bound to BAK reveals an unexpected role for the α1-α2 loop in BAK activation. Cell Death Differ 2022; 29:1757-1768. [PMID: 35279694 PMCID: PMC9433411 DOI: 10.1038/s41418-022-00961-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 11/08/2022] Open
Abstract
Pro-apoptotic BAK and BAX are activated by BH3-only proteins to permeabilise the outer mitochondrial membrane. The antibody 7D10 also activates BAK on mitochondria and its epitope has previously been mapped to BAK residues in the loop connecting helices α1 and α2 of BAK. A crystal structure of the complex between the Fv fragment of 7D10 and the BAK mutant L100A suggests a possible mechanism of activation involving the α1-α2 loop residue M60. M60 mutants of BAK have reduced stability and elevated sensitivity to activation by BID, illustrating that M60, through its contacts with residues in helices α1, α5 and α6, is a linchpin stabilising the inert, monomeric structure of BAK. Our data demonstrate that BAK's α1-α2 loop is not a passive covalent connector between secondary structure elements, but a direct restraint on BAK's activation.
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Affiliation(s)
- Adeline Y Robin
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Michelle S Miller
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Sweta Iyer
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Melissa X Shi
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Ahmad Z Wardak
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Daisy Lio
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Nicholas A Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Brian J Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Richard W Birkinshaw
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Peter E Czabotar
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Ruth M Kluck
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia.
| | - Peter M Colman
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia.
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15
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Sora V, Papaleo E. Structural Details of BH3 Motifs and BH3-Mediated Interactions: an Updated Perspective. Front Mol Biosci 2022; 9:864874. [PMID: 35685242 PMCID: PMC9171138 DOI: 10.3389/fmolb.2022.864874] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/13/2022] [Indexed: 11/18/2022] Open
Abstract
Apoptosis is a mechanism of programmed cell death crucial in organism development, maintenance of tissue homeostasis, and several pathogenic processes. The B cell lymphoma 2 (BCL2) protein family lies at the core of the apoptotic process, and the delicate balance between its pro- and anti-apoptotic members ultimately decides the cell fate. BCL2 proteins can bind with each other and several other biological partners through the BCL2 homology domain 3 (BH3), which has been also classified as a possible Short Linear Motif and whose distinctive features remain elusive even after decades of studies. Here, we aim to provide an updated overview of the structural features characterizing BH3s and BH3-mediated interactions (with a focus on human proteins), elaborating on the plasticity of BCL2 proteins and the motif properties. We also discussed the implication of these findings for the discovery of interactors of the BH3-binding groove of BCL2 proteins and the design of mimetics for therapeutic purposes.
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Affiliation(s)
- Valentina Sora
- Cancer Structural Biology, Danish Cancer Society Research Center, Copenhagen, Denmark
- Cancer Systems Biology, Section for Bioinformatics, Department of Health and Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Elena Papaleo
- Cancer Structural Biology, Danish Cancer Society Research Center, Copenhagen, Denmark
- Cancer Systems Biology, Section for Bioinformatics, Department of Health and Technology, Technical University of Denmark, Kongens Lyngby, Denmark
- *Correspondence: Elena Papaleo, ,
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16
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Protein-protein and protein-lipid interactions of pore-forming BCL-2 family proteins in apoptosis initiation. Biochem Soc Trans 2022; 50:1091-1103. [PMID: 35521828 DOI: 10.1042/bst20220323] [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: 03/03/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 01/26/2023]
Abstract
Apoptosis is a common cell death program that is important in human health and disease. Signaling in apoptosis is largely driven through protein-protein interactions. The BCL-2 family proteins function in protein-protein interactions as key regulators of mitochondrial poration, the process that initiates apoptosis through the release of cytochrome c, which activates the apoptotic caspase cascade leading to cellular demolition. The BCL-2 pore-forming proteins BAK and BAX are the key executors of mitochondrial poration. We review the state of knowledge of protein-protein and protein-lipid interactions governing the apoptotic function of BAK and BAX, as determined through X-ray crystallography and NMR spectroscopy studies. BAK and BAX are dormant, globular α-helical proteins that participate in protein-protein interactions with other pro-death BCL-2 family proteins, transforming them into active, partially unfolded proteins that dimerize and associate with and permeabilize mitochondrial membranes. We compare the protein-protein interactions observed in high-resolution structures with those derived in silico by AlphaFold, making predictions based on combining experimental and in silico approaches to delineate the structural basis for novel protein-protein interaction complexes of BCL-2 family proteins.
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17
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Physiological and pharmacological modulation of BAX. Trends Pharmacol Sci 2022; 43:206-220. [PMID: 34848097 PMCID: PMC8840970 DOI: 10.1016/j.tips.2021.11.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/30/2021] [Accepted: 11/01/2021] [Indexed: 01/29/2023]
Abstract
Bcl-2-associated X protein (BAX) is a critical executioner of mitochondrial regulated cell death through its lethal activity of permeabilizing the mitochondrial outer membrane (MOM). While the physiological function of BAX ensures tissue homeostasis, dysregulation of BAX leads to aberrant cell death. Despite BAX being a promising therapeutic target for human diseases, historically the development of drugs has focused on antiapoptotic BCL-2 proteins, due to challenges in elucidating the mechanism of BAX activation and identifying druggable surfaces of BAX. Here, we discuss recent studies that have provided structure-function insights and identified regulatory surfaces that control BAX activation. Moreover, we emphasize the development of small molecule orthosteric, allosteric, and oligomerization modulators that provide novel opportunities for biological investigation and progress towards drugging BAX.
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18
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Smith NA, Wardak AZ, Cowan AD, Colman PM, Czabotar PE, Smith BJ. The Bak core dimer focuses triacylglycerides in the membrane. Biophys J 2022; 121:347-360. [PMID: 34973947 PMCID: PMC8822611 DOI: 10.1016/j.bpj.2021.12.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/15/2021] [Accepted: 12/28/2021] [Indexed: 02/03/2023] Open
Abstract
Apoptosis, the intrinsic programmed cell death process, is mediated by the Bcl-2 family members Bak and Bax. Activation via formation of symmetric core dimers and oligomerization on the mitochondrial outer membrane (MOM) leads to permeabilization and cell death. Although this process is linked to the MOM, the role of the membrane in facilitating such pores is poorly understood. We recently described Bak core domain dimers, revealing lipid binding sites and an initial role of lipids in oligomerization. Here we describe simulations that identified localized clustering and interaction of triacylglycerides (TAGs) with a minimized Bak dimer construct. Coalescence of TAGs occurred beneath this Bak dimer, mitigating dimer-induced local membrane thinning and curvature in representative coarse-grain MOM and model membrane systems. Furthermore, the effects observed as a result of coarse-grain TAG cluster formation was concentration dependent, scaling from low physiological MOM concentrations to those found in other organelles. We find that increasing the TAG concentration in liposomes mimicking the MOM decreased the ability of activated Bak to permeabilize these liposomes. These results suggest that the presence of TAGs within a Bak-lipid membrane preserves membrane integrity and is associated with reduced membrane stress, suggesting a possible role of TAGs in Bak-mediated apoptosis.
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Affiliation(s)
- Nicholas A. Smith
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
| | - Ahmad Z. Wardak
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Angus D. Cowan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Peter M. Colman
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Peter E. Czabotar
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia,Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Brian J. Smith
- La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia,Corresponding author
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19
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Singh G, Guibao CD, Seetharaman J, Aggarwal A, Grace CR, McNamara DE, Vaithiyalingam S, Waddell MB, Moldoveanu T. Structural basis of BAK activation in mitochondrial apoptosis initiation. Nat Commun 2022; 13:250. [PMID: 35017502 PMCID: PMC8752837 DOI: 10.1038/s41467-021-27851-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 12/14/2021] [Indexed: 12/31/2022] Open
Abstract
BCL-2 proteins regulate mitochondrial poration in apoptosis initiation. How the pore-forming BCL-2 Effector BAK is activated remains incompletely understood mechanistically. Here we investigate autoactivation and direct activation by BH3-only proteins, which cooperate to lower BAK threshold in membrane poration and apoptosis initiation. We define in trans BAK autoactivation as the asymmetric “BH3-in-groove” triggering of dormant BAK by active BAK. BAK autoactivation is mechanistically similar to direct activation. The structure of autoactivated BAK BH3-BAK complex reveals the conformational changes leading to helix α1 destabilization, which is a hallmark of BAK activation. Helix α1 is destabilized and restabilized in structures of BAK engaged by rationally designed, high-affinity activating and inactivating BID-like BH3 ligands, respectively. Altogether our data support the long-standing hit-and-run mechanism of BAK activation by transient binding of BH3-only proteins, demonstrating that BH3-induced structural changes are more important in BAK activation than BH3 ligand affinity. The authors show that the mechanism of BAK activation in mitochondrial apoptosis involves cooperation between direct activation by BH3-only protein BID and BAK autoactivation, providing a unifying basis for BAK triggering by BH3 ligands.
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Affiliation(s)
- Geetika Singh
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.,Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA.,Integrative Biomedical Sciences Program, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA
| | - Cristina D Guibao
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.,Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jayaraman Seetharaman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Anup Aggarwal
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.,Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Christy R Grace
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Dan E McNamara
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.,Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | | | - M Brett Waddell
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA. .,Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA.
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20
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VDAC2 and the BCL-2 family of proteins. Biochem Soc Trans 2021; 49:2787-2795. [PMID: 34913469 PMCID: PMC8786305 DOI: 10.1042/bst20210753] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/21/2021] [Accepted: 11/26/2021] [Indexed: 12/26/2022]
Abstract
The BCL-2 protein family govern whether a cell dies or survives by controlling mitochondrial apoptosis. As dysregulation of mitochondrial apoptosis is a common feature of cancer cells, targeting protein–protein interactions within the BCL-2 protein family is a key strategy to seize control of apoptosis and provide favourable outcomes for cancer patients. Non-BCL-2 family proteins are emerging as novel regulators of apoptosis and are potential drug targets. Voltage dependent anion channel 2 (VDAC2) can regulate apoptosis. However, it is unclear how this occurs at the molecular level, with conflicting evidence in the literature for its role in regulating the BCL-2 effector proteins, BAK and BAX. Notably, VDAC2 is required for efficient BAX-mediated apoptosis, but conversely inhibits BAK-mediated apoptosis. This review focuses on the role of VDAC2 in apoptosis, discussing the current knowledge of the interaction between VDAC2 and BCL-2 family proteins and the recent development of an apoptosis inhibitor that targets the VDAC2–BAK interaction.
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21
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Sperl LE, Rührnößl F, Schiller A, Haslbeck M, Hagn F. High-resolution analysis of the conformational transition of pro-apoptotic Bak at the lipid membrane. EMBO J 2021; 40:e107159. [PMID: 34523144 PMCID: PMC8521305 DOI: 10.15252/embj.2020107159] [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: 10/27/2020] [Revised: 08/09/2021] [Accepted: 08/20/2021] [Indexed: 12/21/2022] Open
Abstract
Permeabilization of the outer mitochondrial membrane by pore-forming Bcl2 proteins is a crucial step for the induction of apoptosis. Despite a large set of data suggesting global conformational changes within pro-apoptotic Bak during pore formation, high-resolution structural details in a membrane environment remain sparse. Here, we used NMR and HDX-MS (Hydrogen deuterium exchange mass spectrometry) in lipid nanodiscs to gain important high-resolution structural insights into the conformational changes of Bak at the membrane that are dependent on a direct activation by BH3-only proteins. Furthermore, we determined the first high-resolution structure of the Bak transmembrane helix. Upon activation, α-helix 1 in the soluble domain of Bak dissociates from the protein and adopts an unfolded and dynamic potentially membrane-bound state. In line with this finding, comparative protein folding experiments with Bak and anti-apoptotic BclxL suggest that α-helix 1 in Bak is a metastable structural element contributing to its pro-apoptotic features. Consequently, mutagenesis experiments aimed at stabilizing α-helix 1 yielded Bak variants with delayed pore-forming activity. These insights will contribute to a better mechanistic understanding of Bak-mediated membrane permeabilization.
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Affiliation(s)
- Laura E Sperl
- Bavarian NMR Center at the Department of ChemistryTechnical University of MunichGarchingGermany
- Institute of Structural BiologyHelmholtz Zentrum MünchenNeuherbergGermany
| | - Florian Rührnößl
- Center for Functional Protein Assemblies and Department of ChemistryTechnical University of MunichGarchingGermany
| | - Anita Schiller
- Bavarian NMR Center at the Department of ChemistryTechnical University of MunichGarchingGermany
- Institute of Structural BiologyHelmholtz Zentrum MünchenNeuherbergGermany
| | - Martin Haslbeck
- Center for Functional Protein Assemblies and Department of ChemistryTechnical University of MunichGarchingGermany
| | - Franz Hagn
- Bavarian NMR Center at the Department of ChemistryTechnical University of MunichGarchingGermany
- Institute of Structural BiologyHelmholtz Zentrum MünchenNeuherbergGermany
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22
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Aslam M, Kanthlal SK, Panonummal R. Peptides: A Supercilious Candidate for Activating Intrinsic Apoptosis by Targeting Mitochondrial Membrane Permeability for Cancer Therapy. Int J Pept Res Ther 2021. [DOI: 10.1007/s10989-021-10297-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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23
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Li K, van Delft MF, Dewson G. Too much death can kill you: inhibiting intrinsic apoptosis to treat disease. EMBO J 2021; 40:e107341. [PMID: 34037273 DOI: 10.15252/embj.2020107341] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/11/2021] [Accepted: 03/18/2021] [Indexed: 02/06/2023] Open
Abstract
Apoptotic cell death is implicated in both physiological and pathological processes. Since many types of cancerous cells intrinsically evade apoptotic elimination, induction of apoptosis has become an attractive and often necessary cancer therapeutic approach. Conversely, some cells are extremely sensitive to apoptotic stimuli leading to neurodegenerative disease and immune pathologies. However, due to several challenges, pharmacological inhibition of apoptosis is still only a recently emerging strategy to combat pathological cell loss. Here, we describe several key steps in the intrinsic (mitochondrial) apoptosis pathway that represent potential targets for inhibitors in disease contexts. We also discuss the mechanisms of action, advantages and limitations of small-molecule and peptide-based inhibitors that have been developed to date. These inhibitors serve as important research tools to dissect apoptotic signalling and may foster new treatments to reduce unwanted cell loss.
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Affiliation(s)
- Kaiming Li
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Royal Parade, Melbourne, VIC, Australia
| | - Mark F van Delft
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Royal Parade, Melbourne, VIC, Australia
| | - Grant Dewson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, University of Melbourne, Royal Parade, Melbourne, VIC, Australia
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24
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Birkinshaw RW, Iyer S, Lio D, Luo CS, Brouwer JM, Miller MS, Robin AY, Uren RT, Dewson G, Kluck RM, Colman PM, Czabotar PE. Structure of detergent-activated BAK dimers derived from the inert monomer. Mol Cell 2021; 81:2123-2134.e5. [PMID: 33794146 DOI: 10.1016/j.molcel.2021.03.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/11/2021] [Accepted: 03/09/2021] [Indexed: 01/27/2023]
Abstract
A body of data supports the existence of core (α2-α5) dimers of BAK and BAX in the oligomeric, membrane-perturbing conformation of these essential apoptotic effector molecules. Molecular structures for these dimers have only been captured for truncated constructs encompassing the core domain alone. Here, we report a crystal structure of BAK α2-α8 dimers (i.e., minus its flexible N-terminal helix and membrane-anchoring C-terminal segment) that has been obtained through the activation of monomeric BAK with the detergent C12E8. Core dimers are evident, linked through the crystal by contacts via latch (α6-α8) domains. This crystal structure shows activated BAK dimers with the extended latch domain present. Our data provide direct evidence for the conformational change converting BAK from inert monomer to the functional dimer that destroys mitochondrial integrity. This dimer is the smallest functional unit for recombinant BAK or BAX described so far.
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Affiliation(s)
- Richard W Birkinshaw
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia.
| | - Sweta Iyer
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Daisy Lio
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Cindy S Luo
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jason M Brouwer
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Michelle S Miller
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Adeline Y Robin
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Rachel T Uren
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Grant Dewson
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Ruth M Kluck
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Peter M Colman
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia.
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25
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Pogmore JP, Uehling D, Andrews DW. Pharmacological Targeting of Executioner Proteins: Controlling Life and Death. J Med Chem 2021; 64:5276-5290. [PMID: 33939407 DOI: 10.1021/acs.jmedchem.0c02200] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Small-molecule mediated modulation of protein interactions of Bcl-2 (B-cell lymphoma-2) family proteins was clinically validated in 2015 when Venetoclax, a selective inhibitor of the antiapoptotic protein BCL-2, achieved breakthrough status designation by the FDA for treatment of lymphoid malignancies. Since then, substantial progress has been made in identifying inhibitors of other interactions of antiapoptosis proteins. However, targeting their pro-apoptotic counterparts, the "executioners" BAX, BAK, and BOK that both initiate and commit the cell to dying, has lagged behind. However, recent publications demonstrate that these proteins can be positively or negatively regulated using small molecule tool compounds. The results obtained with these molecules suggest that pharmaceutical regulation of apoptosis will have broad implications that extend beyond activating cell death in cancer. We review recent advances in identifying compounds and their utility in the exogenous control of life and death by regulating executioner proteins, with emphasis on the prototype BAX.
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Affiliation(s)
- Justin P Pogmore
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1J7, Canada.,Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario M4N 3M5, Canada
| | - David Uehling
- Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, Ontario M5G 1M1, Canada
| | - David W Andrews
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1J7, Canada.,Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario M4N 3M5, Canada
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26
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The Mysteries around the BCL-2 Family Member BOK. Biomolecules 2020; 10:biom10121638. [PMID: 33291826 PMCID: PMC7762061 DOI: 10.3390/biom10121638] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/19/2022] Open
Abstract
BOK is an evolutionarily conserved BCL-2 family member that resembles the apoptotic effectors BAK and BAX in sequence and structure. Based on these similarities, BOK has traditionally been classified as a BAX-like pro-apoptotic protein. However, the mechanism of action and cellular functions of BOK remains controversial. While some studies propose that BOK could replace BAK and BAX to elicit apoptosis, others attribute to this protein an indirect way of apoptosis regulation. Adding to the debate, BOK has been associated with a plethora of non-apoptotic functions that makes this protein unpredictable when dictating cell fate. Here, we compile the current knowledge and open questions about this paradoxical protein with a special focus on its structural features as the key aspect to understand BOK biological functions.
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27
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Neuronal cell life, death, and axonal degeneration as regulated by the BCL-2 family proteins. Cell Death Differ 2020; 28:108-122. [PMID: 33162554 PMCID: PMC7852532 DOI: 10.1038/s41418-020-00654-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 12/17/2022] Open
Abstract
Axonal degeneration and neuronal cell death are fundamental processes in development and contribute to the pathology of neurological disease in adults. Both processes are regulated by BCL-2 family proteins which orchestrate the permeabilization of the mitochondrial outer membrane (MOM). MOM permeabilization (MOMP) results in the activation of pro-apoptotic molecules that commit neurons to either die or degenerate. With the success of small-molecule inhibitors targeting anti-apoptotic BCL-2 proteins for the treatment of lymphoma, we can now envision the use of inhibitors of apoptosis with exquisite selectivity for BCL-2 family protein regulation of neuronal apoptosis in the treatment of nervous system disease. Critical to this development is deciphering which subset of proteins is required for neuronal apoptosis and axon degeneration, and how these two different outcomes are separately regulated. Moreover, noncanonical BCL-2 family protein functions unrelated to the regulation of MOMP, including impacting necroptosis and other modes of cell death may reveal additional potential targets and/or confounders. This review highlights our current understanding of BCL-2 family mediated neuronal cell death and axon degeneration, while identifying future research questions to be resolved to enable regulating neuronal survival pharmacologically.
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28
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Abstract
Bax and Bak, two functionally similar, pro-apoptotic proteins of the Bcl-2 family, are known as the gateway to apoptosis because of their requisite roles as effectors of mitochondrial outer membrane permeabilization (MOMP), a major step during mitochondria-dependent apoptosis. The mechanism of how cells turn Bax/Bak from inert molecules into fully active and lethal effectors had long been the focal point of a major debate centered around two competing, but not mutually exclusive, models: direct activation and indirect activation. After intensive research efforts for over two decades, it is now widely accepted that to initiate apoptosis, some of the BH3-only proteins, a subclass of the Bcl-2 family, directly engage Bax/Bak to trigger their conformational transformation and activation. However, a series of recent discoveries, using previously unavailable CRISPR-engineered cell systems, challenge the basic premise that undergirds the consensus and provide evidence for a novel and surprisingly simple model of Bax/Bak activation: the membrane (lipids)-mediated spontaneous model. This review will discuss the evidence, rationale, significance, and implications of this new model.
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Affiliation(s)
- Xu Luo
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Alaska Medical Center, Omaha, ME, 68198-7696, USA.,Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, 68198-6805, USA
| | - Katelyn L O'Neill
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Alaska Medical Center, Omaha, ME, 68198-7696, USA
| | - Kai Huang
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Alaska Medical Center, Omaha, ME, 68198-7696, USA.,Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, 68198-6805, USA
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29
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Ye K, Meng WX, Sun H, Wu B, Chen M, Pang YP, Gao J, Wang H, Wang J, Kaufmann SH, Dai H. Characterization of an alternative BAK-binding site for BH3 peptides. Nat Commun 2020; 11:3301. [PMID: 32620849 PMCID: PMC7335050 DOI: 10.1038/s41467-020-17074-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 06/05/2020] [Indexed: 01/30/2023] Open
Abstract
Many cellular stresses are transduced into apoptotic signals through modification or up-regulation of the BH3-only subfamily of BCL2 proteins. Through direct or indirect mechanisms, these proteins activate BAK and BAX to permeabilize the mitochondrial outer membrane. While the BH3-only proteins BIM, PUMA, and tBID have been confirmed to directly activate BAK through its canonical BH3 binding groove, whether the BH3-only proteins BMF, HRK or BIK can directly activate BAK is less clear. Here we show that BMF and HRK bind and directly activate BAK. Through NMR studies, site-directed mutagenesis, and advanced molecular dynamics simulations, we also find that BAK activation by BMF and possibly HRK involves a previously unrecognized binding groove formed by BAK α4, α6, and α7 helices. Alterations in this groove decrease the ability of BMF and HRK to bind BAK, permeabilize membranes and induce apoptosis, suggesting a potential role for this BH3-binding site in BAK activation. Mitochondrial apoptosis is controlled by BCL2 family proteins, and the BH3-only proteins often act as sensors that transmit apoptotic signals. Here the authors show how the BH3-only proteins BMF and HRK can directly activate the BCL2 protein BAK and interact with BAK through an alternative binding groove.
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Affiliation(s)
- Kaiqin Ye
- Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China.,Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Wei X Meng
- Division of Oncology Research, Mayo Clinic, Rochester, MN, USA.,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA
| | - Hongbin Sun
- School of Food and Biological Engineering, Zhenzhou University of Light Industry, Zhenzhou, 450002, China
| | - Bo Wu
- CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Meng Chen
- Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China.,Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Yuan-Ping Pang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jia Gao
- Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China.,Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Hongzhi Wang
- Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China.,Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Junfeng Wang
- CAS Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, High Magnetic Field Laboratory, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China
| | - Scott H Kaufmann
- Division of Oncology Research, Mayo Clinic, Rochester, MN, USA. .,Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, 55905, USA.
| | - Haiming Dai
- Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China. .,Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China.
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30
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Laszig S, Boedicker C, Weiser T, Knapp S, Fulda S. The novel dual BET/HDAC inhibitor TW09 mediates cell death by mitochondrial apoptosis in rhabdomyosarcoma cells. Cancer Lett 2020; 486:46-57. [PMID: 32445837 DOI: 10.1016/j.canlet.2020.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/24/2020] [Accepted: 05/11/2020] [Indexed: 12/25/2022]
Abstract
Targeting the epigenome of cancer cells with the combination of Bromodomain and Extra Terminal (BET) protein inhibitors and histone deacetylase (HDAC) inhibitors has shown synergistic antitumor effects in several cancer types. In this study, we investigate the antitumor potential of the novel dual BET/HDAC inhibitor TW09 in rhabdomyosarcoma (RMS) cells. TW09 reduces cell viability, suppresses long-term clonogenic survival and induces cell death in RMS cells in a dose-dependent manner. Compared to BET/HDAC co-inhibition using JQ1 and MS-275, TW09 induces similar cell death at equimolar concentrations and regulates BET and HDAC target proteins (e.g. c-MYC, H3 acetylation). Mechanistic studies revealed that TW09 upregulates BIM, NOXA, PUMA and BMF, while downregulating BCL-XL, leading to proapoptotic rebalancing of BCL-2 proteins. This results in BAK and BAX activation and caspase-dependent apoptosis, since individual genetic silencing of BIM, NOXA, PUMA, BMF, BAK or BAX, overexpression of BCL-2 or the caspase inhibition with zVAD.fmk all rescue JQ1/BYL719-induced cell death. In conclusion, TW09 shows potent antitumor activity in RMS cells in vitro by inducing mitochondrial apoptosis and may represent a promising new therapeutic option for the treatment of RMS.
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Affiliation(s)
- Stephanie Laszig
- Institute for Experimental Cancer Research in Pediatrics, Goethe-University Frankfurt, Komturstrasse 3a, 60528, Frankfurt, Germany
| | - Cathinka Boedicker
- Institute for Experimental Cancer Research in Pediatrics, Goethe-University Frankfurt, Komturstrasse 3a, 60528, Frankfurt, Germany
| | - Tim Weiser
- Institute for Pharmaceutical Chemistry, Goethe-University and Buchmann Institute for Molecular Life Sciences (BMLS), Frankfurt, Germany
| | - Stefan Knapp
- German Cancer Consortium (DKTK), Partner Site Frankfurt, Germany; Institute for Pharmaceutical Chemistry, Goethe-University and Buchmann Institute for Molecular Life Sciences (BMLS), Frankfurt, Germany
| | - Simone Fulda
- Institute for Experimental Cancer Research in Pediatrics, Goethe-University Frankfurt, Komturstrasse 3a, 60528, Frankfurt, Germany; German Cancer Consortium (DKTK), Partner Site Frankfurt, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany.
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31
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Su X, Lv L, Li Y, Fang R, Yang R, Li C, Li T, Zhu D, Li X, Zhou Y, Shan H, Liang H. lncRNA MIRF Promotes Cardiac Apoptosis through the miR-26a-Bak1 Axis. MOLECULAR THERAPY-NUCLEIC ACIDS 2020; 20:841-850. [PMID: 32464547 PMCID: PMC7256443 DOI: 10.1016/j.omtn.2020.05.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/23/2020] [Accepted: 05/01/2020] [Indexed: 01/09/2023]
Abstract
Acute myocardial infarction (AMI) is the leading cause of death worldwide. Identifying the pathways that block cardiac cell death is a therapeutic strategy for ischemic heart disease. We found that long noncoding RNA (lncRNA) myocardial infarction-regulatory factor (MIRF) promoted ischemic myocardial injury by regulating autophagy through targeting miR-26a. However, the role of MIRF-miR-26a in apoptosis during AMI has not been delineated. In this study, we found the downregulation of miR-26a both in the heart of myocardial infarction (MI) mice and in H2O2-treated cardiomyocytes. miR-26a silencing resulted in apoptosis, whereas overexpression of miR-26a attenuated H2O2-induced apoptosis through promoting mitochondrial ATP content and increasing mitochondrial membrane potential (MMP). Moreover, forced expression of miR-26a protected against MI-induced cardiac injury and attenuated cardiac apoptosis. Further studies showed that miR-26a inhibited apoptosis through regulation of Bak1. Furthermore, MIRF decreased ATP content and MMP through regulating miR-26a, which then promoted the cardiomyocyte apoptosis. In contrast, deficiency of MIRF promoted mitochondrial ATP content and increased MMP, and then inhibited MI or H2O2-induced cardiac apoptosis, which was abolished by miR-26a inhibitor. Taken together, these results suggested that MIRF contributed to cardiomyocyte apoptosis through modulating Bak1 by regulation of miR-26a, which can be a potential therapeutic target for the treatment of ischemic heart disease.
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Affiliation(s)
- Xiaomin Su
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Northern Translational Medicine Research and Cooperation Center, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Lifang Lv
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; The Centre of Functional Experiment Teaching, Department of Basic Medicine, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Yue Li
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Northern Translational Medicine Research and Cooperation Center, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Ruonan Fang
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Northern Translational Medicine Research and Cooperation Center, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Rui Yang
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Chao Li
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Tianyu Li
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Northern Translational Medicine Research and Cooperation Center, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Di Zhu
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Xuelian Li
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Yuhong Zhou
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China
| | - Hongli Shan
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Northern Translational Medicine Research and Cooperation Center, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Research Unit of Noninfectious Chronic Diseases in Frigid Zone (2019RU070), Chinese Academy of Medical Sciences, Heilongjiang 150081, P. R. China
| | - Haihai Liang
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Key Laboratory of Cardiovascular Research, Ministry of Education), College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Northern Translational Medicine Research and Cooperation Center, Heilongjiang Academy of Medical Sciences, Harbin Medical University, Harbin, Heilongjiang 150081, P. R. China; Research Unit of Noninfectious Chronic Diseases in Frigid Zone (2019RU070), Chinese Academy of Medical Sciences, Heilongjiang 150081, P. R. China.
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32
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Marimuthu P, Razzokov J, Eshonqulov G. Disruption of conserved polar interactions causes a sequential release of Bim mutants from the canonical binding groove of Mcl1. Int J Biol Macromol 2020; 158:364-374. [PMID: 32376253 DOI: 10.1016/j.ijbiomac.2020.04.243] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/25/2020] [Accepted: 04/27/2020] [Indexed: 12/15/2022]
Abstract
Mcl1 is an important anti-apoptotic member of the Bcl2 family proteins that are upregulated in several cancer malignancies. The canonical binding groove (CBG) located at the surface of Mcl1 exhibits a critical role in binding partners selectively via the BH3-domain of pro-apoptotic Bcl2 family members that trigger the downregulation of Mcl1 function. There are several crystal structures of point-mutated pro-apoptotic Bim peptides in complex with Mcl1. However, the mechanistic effects of such point-mutations towards peptide binding and complex stability still remain unexplored. Here, the effects of the reported point mutations in Bim peptides and their binding mechanisms to Mcl1 were computationally evaluated using atomistic-level steered molecular dynamics (SMD) simulations. A range of external-forces and constant-velocities were applied to the Bim peptides to uncover the mechanistic basis of peptide dissociation from the CBG of Mcl1. Although the peptides showed similarities in their dissociation pathways, the peak rupture forces varied significantly. According to simulations results, the disruption of the conserved polar contacts at the complex interface causes a sequential release of the peptides from the CBG of Mcl1. Overall, the results obtained from the current study may provide valuable insights for the development of novel anti-cancer peptide-inhibitors that can downregulate Mcl1's function.
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Affiliation(s)
- Parthiban Marimuthu
- Structural Bioinformatics Laboratory (SBL), Biochemistry and Pharmacy, Faculty of Science and Engineering, Åbo Akademi University, FI-20520 Turku, Finland.
| | - Jamoliddin Razzokov
- Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp, Belgium
| | - Gofur Eshonqulov
- Department of Physics, National University of Uzbekistan, 100174 Tashkent, Uzbekistan
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33
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Separase-triggered apoptosis enforces minimal length of mitosis. Nature 2020; 580:542-547. [PMID: 32322059 DOI: 10.1038/s41586-020-2187-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 02/10/2020] [Indexed: 01/13/2023]
Abstract
Prolonged mitosis often results in apoptosis1. Shortened mitosis causes tumorigenic aneuploidy, but it is unclear whether it also activates the apoptotic machinery2. Separase, a cysteine protease and trigger of all eukaryotic anaphases, has a caspase-like catalytic domain but has not previously been associated with cell death3,4. Here we show that human cells that enter mitosis with already active separase rapidly undergo death in mitosis owing to direct cleavage of anti-apoptotic MCL1 and BCL-XL by separase. Cleavage not only prevents MCL1 and BCL-XL from sequestering pro-apoptotic BAK, but also converts them into active promoters of death in mitosis. Our data strongly suggest that the deadliest cleavage fragment, the C-terminal half of MCL1, forms BAK/BAX-like pores in the mitochondrial outer membrane. MCL1 and BCL-XL are turned into separase substrates only upon phosphorylation by NEK2A. Early mitotic degradation of this kinase is therefore crucial for preventing apoptosis upon scheduled activation of separase in metaphase. Speeding up mitosis by abrogation of the spindle assembly checkpoint results in a temporal overlap of the enzymatic activities of NEK2A and separase and consequently in cell death. We propose that NEK2A and separase jointly check on spindle assembly checkpoint integrity and eliminate cells that are prone to chromosome missegregation owing to accelerated progression through early mitosis.
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34
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Moldoveanu T, Czabotar PE. BAX, BAK, and BOK: A Coming of Age for the BCL-2 Family Effector Proteins. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a036319. [PMID: 31570337 DOI: 10.1101/cshperspect.a036319] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The BCL-2 family of proteins control a key checkpoint in apoptosis, that of mitochondrial outer membrane permeabilization or, simply, mitochondrial poration. The family consists of three subgroups: BH3-only initiators that respond to apoptotic stimuli; antiapoptotic guardians that protect against cell death; and the membrane permeabilizing effectors BAX, BAK, and BOK. On activation, effector proteins are converted from inert monomers into membrane permeabilizing oligomers. For many years, this process has been poorly understood at the molecular level, but a number of recent advances have provided important insights. We review the regulation of these effectors, their activation, subsequent conformational changes, and the ensuing oligomerization events that enable mitochondrial poration, which initiates apoptosis through release of key signaling factors such as cytochrome c We highlight the mysteries that remain in understanding these important proteins in an endeavor to provide a comprehensive picture of where the field currently sits and where it is moving toward.
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Affiliation(s)
- Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.,Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis Tennessee 38105, USA
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, University of Melbourne, Parkville, Victoria 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
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35
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Dai Y, Zhao XJ, Li F, Yuan Y, Yan DM, Cao H, Huang XY, Hu Z, Ma D, Gao QL. Truncated Bid Regulates Cisplatin Response via Activation of Mitochondrial Apoptosis Pathway in Ovarian Cancer. Hum Gene Ther 2020; 31:325-338. [PMID: 32024383 DOI: 10.1089/hum.2019.206] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Refractoriness to conventional chemotherapy is a major challenge in the treatment of advanced ovarian cancer (OC). There is increasing evidence that mitochondrial priming correlates with cisplatin response in various cancers. Notably, Bim and Bid, two of the proapoptotic BH3-only proteins, are recognized as the most effective inducers of mitochondrial priming in OC. In this study, we constructed two tumor-specific oncolytic adenoviruses (Ads) coding for Bim (Ad-Bim) or truncated Bid (Ad-tBid), respectively, and performed gain-of-function assays in nine OC cell lines. Ad-tBid exhibited significant antitumor efficacy than the controls. On addition of Ad-tBid pretreatment, mito-primed cells displayed more sensitivity to cisplatin both in vitro and ex vivo. We also found that Ad-tBid induced mitochondrial apoptosis in a Bak-dependent manner. Furthermore, a combined cisplatin plus Ad-tBid therapy markedly inhibited tumor growth in a subcutaneous xenotransplanted tumor model. In mice bearing peritoneal disseminated OC, intraperitoneal administration of Ad-tBid potentiated the antitumor effect of cisplatin. Our findings suggest that Ad-tBid enhances cisplatin response in OC cells, establishing the potential treatment of advanced OC via a combination of cisplatin and Ad-tBid.
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Affiliation(s)
- Yun Dai
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Xue-Jiao Zhao
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Fei Li
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Yuan Yuan
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Dan-Mei Yan
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Heng Cao
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Xiao-Yuan Huang
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Zheng Hu
- Department of Obstetrics and Gynecology, Precision Medicine Institute, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China
| | - Ding Ma
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
| | - Qing-Lei Gao
- Cancer Biology Research Center (Key Laboratory of the Ministry of Education), Tongji Medical College, Huazhong University of Science and Technology, Tongji Hospital, Wuhan, People's Republic of China
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36
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Bock FJ, Tait SWG. Mitochondria as multifaceted regulators of cell death. Nat Rev Mol Cell Biol 2020; 21:85-100. [PMID: 31636403 DOI: 10.1038/s41580-019-0173-8] [Citation(s) in RCA: 1243] [Impact Index Per Article: 310.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2019] [Indexed: 12/12/2022]
Abstract
Through their many and varied metabolic functions, mitochondria power life. Paradoxically, mitochondria also have a central role in apoptotic cell death. Upon induction of mitochondrial apoptosis, mitochondrial outer membrane permeabilization (MOMP) usually commits a cell to die. Apoptotic signalling downstream of MOMP involves cytochrome c release from mitochondria and subsequent caspase activation. As such, targeting MOMP in order to manipulate cell death holds tremendous therapeutic potential across different diseases, including neurodegenerative diseases, autoimmune disorders and cancer. In this Review, we discuss new insights into how mitochondria regulate apoptotic cell death. Surprisingly, recent data demonstrate that besides eliciting caspase activation, MOMP engages various pro-inflammatory signalling functions. As we highlight, together with new findings demonstrating cell survival following MOMP, this pro-inflammatory role suggests that mitochondria-derived signalling downstream of pro-apoptotic cues may also have non-lethal functions. Finally, we discuss the importance and roles of mitochondria in other forms of regulated cell death, including necroptosis, ferroptosis and pyroptosis. Collectively, these new findings offer exciting, unexplored opportunities to target mitochondrial regulation of cell death for clinical benefit.
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Affiliation(s)
- Florian J Bock
- Cancer Research UK Beatson Institute, Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Stephen W G Tait
- Cancer Research UK Beatson Institute, Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
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37
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Vila-Julià G, Granadino-Roldán JM, Perez JJ, Rubio-Martinez J. Molecular Determinants for the Activation/Inhibition of Bak Protein by BH3 Peptides. J Chem Inf Model 2020; 60:1632-1643. [PMID: 31944696 DOI: 10.1021/acs.jcim.9b01047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Apoptosis is a key cell death pathway in mammalian cells. Understanding this process and its regulation has been a subject of study in the last three decades. Members of the Bcl-2 family of proteins are involved in the regulation of apoptosis through mitochondrial poration with the subsequent initiation of apoptosis. Deregulation of proapoptotic proteins contributes to the progression of many tumor processes. Understanding how these pore-forming Bcl-2 proteins Bak and Bax are activated is key to find new anticancer treatments. As no drug capable of activating Bak has been disclosed yet, the study of the structural features of BH3 peptides-known as Bak activators-relevant for binding along with its binding energy decomposition analysis, becomes essential for designing novel small-molecule mimics of BH3. Interestingly, a BH3 Bim analogue-inactivating Bak has recently been discovered, opening a question on the molecular features that determine the functions of BH3 peptides. Therefore, the present work is aimed at understanding the way BH3 peptides activate or inactivate Bak in order to identify differential structural features that can be used in drug design. For this purpose, complexes of Bak with an activator and an inhibitor have been subjected to a molecular dynamics study. Structural differences were assessed by means of the fluctuations of the corresponding principal components. Moreover, the MMPB/GBSA approach was used to compute the binding free energy of the diverse complexes to identify those residues of the BH3 peptide that exhibit the larger contributions to complex formation. The results obtained in this work show differences between activators and inhibitors, both in structural and energetic terms, which can be used in the design of new molecules that can activate or inactivate proapoptotic Bak.
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Affiliation(s)
- Guillem Vila-Julià
- Department of Materials Science and Physical Chemistry, University of Barcelona and the Institut de Recerca en Quimica Teorica i Computacional (IQTCUB), 08028 Barcelona, Spain.,Department of Chemical Engineering, Universitat Politecnica de Catalunya- Barcelona Tech., Av. Diagonal, 647, 08028 Barcelona, Spain
| | - José M Granadino-Roldán
- Departamento de Química Física y Analítica, Facultad de Ciencias Experimentales, Universidad de Jaén, Campus "Las Lagunillas" s/n, 23071 Jaén, Spain
| | - Juan J Perez
- Department of Chemical Engineering, Universitat Politecnica de Catalunya- Barcelona Tech., Av. Diagonal, 647, 08028 Barcelona, Spain
| | - Jaime Rubio-Martinez
- Department of Materials Science and Physical Chemistry, University of Barcelona and the Institut de Recerca en Quimica Teorica i Computacional (IQTCUB), 08028 Barcelona, Spain
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38
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Zheng JH, Grace CR, Guibao CD, McNamara DE, Llambi F, Wang YM, Chen T, Moldoveanu T. Intrinsic Instability of BOK Enables Membrane Permeabilization in Apoptosis. Cell Rep 2019; 23:2083-2094.e6. [PMID: 29768206 PMCID: PMC6500462 DOI: 10.1016/j.celrep.2018.04.060] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/21/2018] [Accepted: 04/14/2018] [Indexed: 11/26/2022] Open
Abstract
The effector B cell lymphoma-2 (BCL-2) protein BCL-2 ovarian killer (BOK) induces mitochondrial outer membrane permeabilization (MOMP) to initiate apoptosis upon inhibition of the proteasome. How BOK mediates MOMP is mechanistically unknown. The NMR structure of the BCL-2 core of human BOK reveals a conserved architecture with an atypical hydrophobic groove that undergoes conformational exchange. Remarkably, the BCL-2 core of BOK spontaneously associates with purified mitochondria to release cytochrome c in MOMP assays. Alanine substitution of a unique glycine in helix α1 stabilizes BOK, as shown by thermal shift and urea denaturation analyses, and significantly inhibits MOMP, liposome permeabilization, and cell death. Activated BID does not activate WT BOK or the stabilized alanine mutant to promote cell death. We propose that BOK-mediated membrane permeabilization is governed in part by its unique metastability of the hydrophobic groove and helix α1 and not through activation by BH3 ligands.
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Affiliation(s)
- Janet H Zheng
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christy R Grace
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Cristina D Guibao
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Dan E McNamara
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | | - Yue-Ming Wang
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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39
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A small molecule interacts with VDAC2 to block mouse BAK-driven apoptosis. Nat Chem Biol 2019; 15:1057-1066. [PMID: 31591564 DOI: 10.1038/s41589-019-0365-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 08/15/2019] [Indexed: 02/07/2023]
Abstract
Activating the intrinsic apoptosis pathway with small molecules is now a clinically validated approach to cancer therapy. In contrast, blocking apoptosis to prevent the death of healthy cells in disease settings has not been achieved. Caspases have been favored, but they act too late in apoptosis to provide long-term protection. The critical step in committing a cell to death is activation of BAK or BAX, pro-death BCL-2 proteins mediating mitochondrial damage. Apoptosis cannot proceed in their absence. Here we show that WEHI-9625, a novel tricyclic sulfone small molecule, binds to VDAC2 and promotes its ability to inhibit apoptosis driven by mouse BAK. In contrast to caspase inhibitors, WEHI-9625 blocks apoptosis before mitochondrial damage, preserving cellular function and long-term clonogenic potential. Our findings expand on the key role of VDAC2 in regulating apoptosis and demonstrate that blocking apoptosis at an early stage is both advantageous and pharmacologically tractable.
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40
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Walensky LD. Targeting BAX to drug death directly. Nat Chem Biol 2019; 15:657-665. [PMID: 31209350 DOI: 10.1038/s41589-019-0306-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/10/2019] [Indexed: 02/07/2023]
Abstract
BCL-2 family protein interactions regulate apoptosis, a critical process that maintains tissue homeostasis but can cause a host of human diseases when deregulated. Venetoclax is the first FDA-approved drug to reactivate apoptosis in cancer by selectively targeting an anti-apoptotic BCL-2 family member. The drug's activity relies on an 'inhibit the inhibitor' mechanism, whereby blockade of a key surface groove on BCL-2 disables its capacity to neutralize pro-apoptotic effectors, such as BAX, a chief executioner protein of the apoptotic pathway. A series of physiologic and pharmacologic regulatory sites that mediate the activation or inhibition of BAX have recently been identified, providing blueprints for the development of alternative apoptosis modulators to block pathologic cell survival or avert unwanted cell death by drugging BAX directly.
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Affiliation(s)
- Loren D Walensky
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA, USA.
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41
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The Structural Biology of Bcl-x L. Int J Mol Sci 2019; 20:ijms20092234. [PMID: 31067648 PMCID: PMC6540150 DOI: 10.3390/ijms20092234] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 01/12/2023] Open
Abstract
Interactions between the pro-survival and pro-apoptotic members of the Bcl-2 family of proteins dictate whether a cell lives or dies. Much of our knowledge of the molecular details of these interactions has come from biochemical and structural studies on the pro-survival protein Bcl-xL. The first high-resolution structure of any Bcl-2 family member was of Bcl-xL, which revealed the conserved topology amongst all family members. Subsequent structures of Bcl-xL complexes with pro-apoptotic ligands demonstrated the general features of all pro-survival:pro-apoptotic complexes. Structural studies involving Bcl-xL were also the basis for the discovery of the first small-molecule pro-survival protein inhibitors, leading ultimately to the development of a new class of drugs now successfully used for cancer treatment in the clinic. This article will review our current knowledge of the structural biology of Bcl-xL and how this has impacted our understanding of the molecular details of the intrinsic apoptotic pathway.
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42
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Investigating the Molecular Basis of N-Substituted 1-Hydroxy-4-Sulfamoyl-2-Naphthoate Compounds Binding to Mcl1. Processes (Basel) 2019. [DOI: 10.3390/pr7040224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Myeloid cell leukemia-1 (Mcl1) is an anti–apoptotic protein that has gained considerable attention due to its overexpression activity prevents cell death. Therefore, a potential inhibitor that specifically targets Mcl1 with higher binding affinity is necessary. Recently, a series of N-substituted 1-hydroxy-4-sulfamoyl-2-naphthoate compounds was reported that targets Mcl1, but its binding mechanism remains unexplored. Here, we attempted to explore the molecular mechanism of binding to Mcl1 using advanced computational approaches: pharmacophore-based 3D-QSAR, docking, and MD simulation. The selected pharmacophore—NNRRR—yielded a statistically significant 3D-QSAR model containing high confidence scores (R2 = 0.9209, Q2 = 0.8459, and RMSE = 0.3473). The contour maps—comprising hydrogen bond donor, hydrophobic, negative ionic and electron withdrawal effects—from our 3D-QSAR model identified the favorable regions crucial for maximum activity. Furthermore, the external validation of the selected model using enrichment and decoys analysis reveals a high predictive power. Also, the screening capacity of the selected model had scores of 0.94, 0.90, and 8.26 from ROC, AUC, and RIE analysis, respectively. The molecular docking of the highly active compound—C40; 4-(N-benzyl-N-(4-(4-chloro-3,5-dimethylphenoxy) phenyl) sulfamoyl)-1-hydroxy-2-naphthoate—predicted the low-energy conformational pose, and the MD simulation revealed crucial details responsible for the molecular mechanism of binding with Mcl1.
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43
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Dengler MA, Robin AY, Gibson L, Li MX, Sandow JJ, Iyer S, Webb AI, Westphal D, Dewson G, Adams JM. BAX Activation: Mutations Near Its Proposed Non-canonical BH3 Binding Site Reveal Allosteric Changes Controlling Mitochondrial Association. Cell Rep 2019; 27:359-373.e6. [DOI: 10.1016/j.celrep.2019.03.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/13/2019] [Accepted: 03/12/2019] [Indexed: 12/26/2022] Open
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44
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Ke FFS, Vanyai HK, Cowan AD, Delbridge ARD, Whitehead L, Grabow S, Czabotar PE, Voss AK, Strasser A. Embryogenesis and Adult Life in the Absence of Intrinsic Apoptosis Effectors BAX, BAK, and BOK. Cell 2019; 173:1217-1230.e17. [PMID: 29775594 DOI: 10.1016/j.cell.2018.04.036] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 01/31/2018] [Accepted: 04/25/2018] [Indexed: 12/01/2022]
Abstract
Intrinsic apoptosis, reliant on BAX and BAK, has been postulated to be fundamental for morphogenesis, but its precise contribution to this process has not been fully explored in mammals. Our structural analysis of BOK suggests close resemblance to BAX and BAK structures. Notably, Bok-/-Bax-/-Bak-/- animals exhibited more severe defects and died earlier than Bax-/-Bak-/- mice, implying that BOK has overlapping roles with BAX and BAK during developmental cell death. By analyzing Bok-/-Bax-/-Bak-/- triple-knockout mice whose cells are incapable of undergoing intrinsic apoptosis, we identified tissues that formed well without this process. We provide evidence that necroptosis, pyroptosis, or autophagy does not substantially substitute for the loss of apoptosis. Albeit very rare, unexpected attainment of adult Bok-/-Bax-/-Bak-/- mice suggests that morphogenesis can proceed entirely without apoptosis mediated by these proteins and possibly without cell death in general.
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Affiliation(s)
- Francine F S Ke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
| | - Hannah K Vanyai
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Angus D Cowan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Alex R D Delbridge
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Lachlan Whitehead
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Stephanie Grabow
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Anne K Voss
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
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45
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Bernardini JP, Brouwer JM, Tan IK, Sandow JJ, Huang S, Stafford CA, Bankovacki A, Riffkin CD, Wardak AZ, Czabotar PE, Lazarou M, Dewson G. Parkin inhibits BAK and BAX apoptotic function by distinct mechanisms during mitophagy. EMBO J 2018; 38:embj.201899916. [PMID: 30573668 DOI: 10.15252/embj.201899916] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 11/08/2018] [Accepted: 11/13/2018] [Indexed: 12/26/2022] Open
Abstract
The E3 ubiquitin ligase Parkin is a key effector of the removal of damaged mitochondria by mitophagy. Parkin determines cell fate in response to mitochondrial damage, with its loss promoting early onset Parkinson's disease and potentially also cancer progression. Controlling a cell's apoptotic response is essential to co-ordinate the removal of damaged mitochondria. We report that following mitochondrial damage-induced mitophagy, Parkin directly ubiquitinates the apoptotic effector protein BAK at a conserved lysine in its hydrophobic groove, a region that is crucial for BAK activation by BH3-only proteins and its homo-dimerisation during apoptosis. Ubiquitination inhibited BAK activity by impairing its activation and the formation of lethal BAK oligomers. Parkin also suppresses BAX-mediated apoptosis, but in the absence of BAX ubiquitination suggesting an indirect mechanism. In addition, we find that BAK-dependent mitochondrial outer membrane permeabilisation during apoptosis promotes PINK1-dependent Parkin activation. Hence, we propose that Parkin directly inhibits BAK to suppress errant apoptosis, thereby allowing the effective clearance of damaged mitochondria, but also promotes clearance of apoptotic mitochondria to limit their potential pro-inflammatory effect.
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Affiliation(s)
- Jonathan P Bernardini
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Jason M Brouwer
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Iris Kl Tan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Jarrod J Sandow
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Shuai Huang
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Che A Stafford
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Aleksandra Bankovacki
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Christopher D Riffkin
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Ahmad Z Wardak
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
| | - Michael Lazarou
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute Monash University, Clayton, Melbourne, Vic., Australia
| | - Grant Dewson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, Vic., Australia .,Department of Medical Biology, University of Melbourne, Parkville, Melbourne, Vic., Australia
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46
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Xu X, Liu Q, He S, Zhao J, Wang N, Han X, Guo Y. Qiang-Xin 1 Formula Prevents Sepsis-Induced Apoptosis in Murine Cardiomyocytes by Suppressing Endoplasmic Reticulum- and Mitochondria-Associated Pathways. Front Pharmacol 2018; 9:818. [PMID: 30104976 PMCID: PMC6077999 DOI: 10.3389/fphar.2018.00818] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 07/09/2018] [Indexed: 12/29/2022] Open
Abstract
Sepsis is reported to be an unusual systemic reaction to infection, accompanied by multiple-organ failure. Sepsis-induced cardiomyopathy (SIC), defined as damages and dysfunction of the heart, is essential in the pathogenesis of sepsis. Traditional Chinese formula, which has long been used to improve the situation of patients through multitarget regulation, is now gradually being used as complementary therapy. The present study aimed to investigate the effect of Qiang-Xin 1 (QX1) formula, a traditional Chinese herbal medicine designed for cardiac dysfunction, on cecal ligation puncture (CLP)-induced heart damage and its underlying mechanisms in mice. Survival test first showed that an oral administration of QX1 formula significantly increased the 7-days survival of septic mice from 22 to 40%. By estimating the secretion of serum cytokines, QX1 treatment dramatically inhibited the excessive production of interleukin-1β and tumor necrosis factor-α. Immunohistochemical staining illustrated that the expression of c-Jun N-terminal kinase, caspase-12, and high-mobility group box 1 was downregulated in cardiomyocytes of the QX1-treated group compared with that of the CLP surgery group. Western blotting confirmed that the activation of essential caspase family members, such as caspase-3, caspase-9, and caspase-12, was prohibited by treatment with QX1. Moreover, the abnormal expression of key regulators of endoplasmic reticulum (ER) and mitochondria-associated apoptosis in cardiomyocytes of septic mice, including CHOP, GRP78, Cyt-c, Bcl-2, Bcl-XL, and Bax, was effectively reversed by treatment with QX1 formula. This study provided a new insight into the role of QX1 formula in heart damage and potential complementary therapeutic effect of traditional Chinese medicine on sepsis.
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Affiliation(s)
- Xiaolong Xu
- Beijing Hospital of Traditional Chinese Medicine, Affiliated with Capital Medical University, Beijing, China.,Beijing Institute of Traditional Chinese Medicine, Beijing, China.,Beijing Key Laboratory of Basic Research with Traditional Chinese Medicine on Infectious Diseases, Beijing, China
| | - Qingquan Liu
- Beijing Hospital of Traditional Chinese Medicine, Affiliated with Capital Medical University, Beijing, China.,Beijing Institute of Traditional Chinese Medicine, Beijing, China.,Beijing Key Laboratory of Basic Research with Traditional Chinese Medicine on Infectious Diseases, Beijing, China
| | - Shasha He
- Beijing Hospital of Traditional Chinese Medicine, Affiliated with Capital Medical University, Beijing, China.,Beijing Institute of Traditional Chinese Medicine, Beijing, China.,Beijing Key Laboratory of Basic Research with Traditional Chinese Medicine on Infectious Diseases, Beijing, China
| | - Jingxia Zhao
- Beijing Hospital of Traditional Chinese Medicine, Affiliated with Capital Medical University, Beijing, China.,Beijing Institute of Traditional Chinese Medicine, Beijing, China.,Beijing Key Laboratory of Basic Research with Traditional Chinese Medicine on Infectious Diseases, Beijing, China
| | - Ning Wang
- Beijing Hospital of Traditional Chinese Medicine, Affiliated with Capital Medical University, Beijing, China.,Beijing Institute of Traditional Chinese Medicine, Beijing, China
| | - Xuyang Han
- Beijing Hospital of Traditional Chinese Medicine, Affiliated with Capital Medical University, Beijing, China.,Beijing Institute of Traditional Chinese Medicine, Beijing, China
| | - Yuhong Guo
- Beijing Hospital of Traditional Chinese Medicine, Affiliated with Capital Medical University, Beijing, China.,Beijing Institute of Traditional Chinese Medicine, Beijing, China.,Beijing Key Laboratory of Basic Research with Traditional Chinese Medicine on Infectious Diseases, Beijing, China
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47
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Tian W, Chen C, Lei X, Zhao J, Liang J. CASTp 3.0: computed atlas of surface topography of proteins. Nucleic Acids Res 2018; 46:W363-W367. [PMID: 29860391 PMCID: PMC6031066 DOI: 10.1093/nar/gky473] [Citation(s) in RCA: 1150] [Impact Index Per Article: 191.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/04/2018] [Accepted: 05/17/2018] [Indexed: 12/23/2022] Open
Abstract
Geometric and topological properties of protein structures, including surface pockets, interior cavities and cross channels, are of fundamental importance for proteins to carry out their functions. Computed Atlas of Surface Topography of proteins (CASTp) is a web server that provides online services for locating, delineating and measuring these geometric and topological properties of protein structures. It has been widely used since its inception in 2003. In this article, we present the latest version of the web server, CASTp 3.0. CASTp 3.0 continues to provide reliable and comprehensive identifications and quantifications of protein topography. In addition, it now provides: (i) imprints of the negative volumes of pockets, cavities and channels, (ii) topographic features of biological assemblies in the Protein Data Bank, (iii) improved visualization of protein structures and pockets, and (iv) more intuitive structural and annotated information, including information of secondary structure, functional sites, variant sites and other annotations of protein residues. The CASTp 3.0 web server is freely accessible at http://sts.bioe.uic.edu/castp/.
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Affiliation(s)
- Wei Tian
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Chang Chen
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xue Lei
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jieling Zhao
- Institut National de Recherche en Informatique et en Automatique, Paris 75012, France
| | - Jie Liang
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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