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Mahboubi H, Yu H, Malca M, McCusty D, Stochaj U. Pifithrin-µ Induces Stress Granule Formation, Regulates Cell Survival, and Rewires Cellular Signaling. Cells 2024; 13:885. [PMID: 38891018 PMCID: PMC11172192 DOI: 10.3390/cells13110885] [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: 12/20/2023] [Revised: 04/30/2024] [Accepted: 05/15/2024] [Indexed: 06/20/2024] Open
Abstract
(1) Background: Stress granules (SGs) are cytoplasmic protein-RNA condensates that assemble in response to various insults. SG production is driven by signaling pathways that are relevant to human disease. Compounds that modulate SG characteristics are therefore of clinical interest. Pifithrin-µ is a candidate anti-tumor agent that inhibits members of the hsp70 chaperone family. While hsp70s are required for granulostasis, the impact of pifithrin-µ on SG formation is unknown. (2) Methods: Using HeLa cells as model system, cell-based assays evaluated the effects of pifithrin-µ on cell viability. Quantitative Western blotting assessed cell signaling events and SG proteins. Confocal microscopy combined with quantitative image analyses examined multiple SG parameters. (3) Results: Pifithrin-µ induced bona fide SGs in the absence of exogenous stress. These SGs were dynamic; their properties were determined by the duration of pifithrin-µ treatment. The phosphorylation of eIF2α was mandatory to generate SGs upon pifithrin-µ exposure. Moreover, the formation of pifithrin-µ SGs was accompanied by profound changes in cell signaling. Pifithrin-µ reduced the activation of 5'-AMP-activated protein kinase, whereas the pro-survival protein kinase Akt was activated. Long-term pifithrin-µ treatment caused a marked loss of cell viability. (4) Conclusions: Our study identified stress-related changes in cellular homeostasis that are elicited by pifithrin-µ. These insights are important knowledge for the appropriate therapeutic use of pifithrin-µ and related compounds.
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Affiliation(s)
- Hicham Mahboubi
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada (H.Y.); (M.M.)
| | - Henry Yu
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada (H.Y.); (M.M.)
| | - Michael Malca
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada (H.Y.); (M.M.)
| | - David McCusty
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada (H.Y.); (M.M.)
| | - Ursula Stochaj
- Department of Physiology, McGill University, Montreal, QC H3G 1Y6, Canada (H.Y.); (M.M.)
- Quantitative Life Sciences Program, McGill University, Montreal, QC H3G 1Y6, Canada
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2
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Rodina A, Xu C, Digwal CS, Joshi S, Patel Y, Santhaseela AR, Bay S, Merugu S, Alam A, Yan P, Yang C, Roychowdhury T, Panchal P, Shrestha L, Kang Y, Sharma S, Almodovar J, Corben A, Alpaugh ML, Modi S, Guzman ML, Fei T, Taldone T, Ginsberg SD, Erdjument-Bromage H, Neubert TA, Manova-Todorova K, Tsou MFB, Young JC, Wang T, Chiosis G. Systems-level analyses of protein-protein interaction network dysfunctions via epichaperomics identify cancer-specific mechanisms of stress adaptation. Nat Commun 2023; 14:3742. [PMID: 37353488 PMCID: PMC10290137 DOI: 10.1038/s41467-023-39241-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 06/05/2023] [Indexed: 06/25/2023] Open
Abstract
Systems-level assessments of protein-protein interaction (PPI) network dysfunctions are currently out-of-reach because approaches enabling proteome-wide identification, analysis, and modulation of context-specific PPI changes in native (unengineered) cells and tissues are lacking. Herein, we take advantage of chemical binders of maladaptive scaffolding structures termed epichaperomes and develop an epichaperome-based 'omics platform, epichaperomics, to identify PPI alterations in disease. We provide multiple lines of evidence, at both biochemical and functional levels, demonstrating the importance of these probes to identify and study PPI network dysfunctions and provide mechanistically and therapeutically relevant proteome-wide insights. As proof-of-principle, we derive systems-level insight into PPI dysfunctions of cancer cells which enabled the discovery of a context-dependent mechanism by which cancer cells enhance the fitness of mitotic protein networks. Importantly, our systems levels analyses support the use of epichaperome chemical binders as therapeutic strategies aimed at normalizing PPI networks.
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Affiliation(s)
- Anna Rodina
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Chao Xu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Chander S Digwal
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Suhasini Joshi
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Yogita Patel
- Department of Biochemistry, Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, QC, H3G 0B1, Canada
| | - Anand R Santhaseela
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Sadik Bay
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Swathi Merugu
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Aftab Alam
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Pengrong Yan
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Chenghua Yang
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Tanaya Roychowdhury
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Palak Panchal
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Liza Shrestha
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Yanlong Kang
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Sahil Sharma
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Justina Almodovar
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Adriana Corben
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Maimonides Medical Center, Brooklyn, NY, USA
| | - Mary L Alpaugh
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Rowan University, Glassboro, NJ, USA
| | - Shanu Modi
- Department of Medicine, Division of Solid Tumors, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Monica L Guzman
- Department of Medicine, Division of Hematology Oncology, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Teng Fei
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Tony Taldone
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Stephen D Ginsberg
- Departments of Psychiatry, Neuroscience & Physiology & the NYU Neuroscience Institute, NYU Grossman School of Medicine, New York, NY, 10016, USA
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, 10962, USA
| | - Hediye Erdjument-Bromage
- Department of Neuroscience and Physiology and Neuroscience Institute, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Thomas A Neubert
- Department of Neuroscience and Physiology and Neuroscience Institute, NYU Grossman School of Medicine, New York, NY, 10016, USA
| | - Katia Manova-Todorova
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Meng-Fu Bryan Tsou
- Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Jason C Young
- Department of Biochemistry, Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, QC, H3G 0B1, Canada
| | - Tai Wang
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
| | - Gabriela Chiosis
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
- Department of Medicine, Division of Solid Tumors, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
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3
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Fang CT, Kuo HH, Amartuvshin O, Hsu HJ, Liu SL, Yao JS, Yih LH. Inhibition of acetyl-CoA carboxylase impaired tubulin palmitoylation and induced spindle abnormalities. Cell Death Dis 2023; 9:4. [PMID: 36617578 PMCID: PMC9826786 DOI: 10.1038/s41420-023-01301-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/20/2022] [Accepted: 01/03/2023] [Indexed: 01/10/2023]
Abstract
Tubulin s-palmitoylation involves the thioesterification of a cysteine residue in tubulin with palmitate. The palmitate moiety is produced by the fatty acid synthesis pathway, which is rate-limited by acetyl-CoA carboxylase (ACC). While it is known that ACC is phosphorylated at serine 79 (pSer79) by AMPK and accumulates at the spindle pole (SP) during mitosis, a functional role for tubulin palmitoylation during mitosis has not been identified. In this study, we found that modulating pSer79-ACC level at the SP using AMPK agonist and inhibitor induced spindle defects. Loss of ACC function induced spindle abnormalities in cell lines and in germ cells of the Drosophila germarium, and palmitic acid (PA) rescued the spindle defects in the cell line treated transiently with the ACC inhibitor, TOFA. Furthermore, inhibition of protein palmitoylating or depalmitoylating enzymes also induced spindle defects. Together, these data suggested that precisely regulated cellular palmitate level and protein palmitoylation may be required for accurate spindle assembly. We then showed that tubulin was largely palmitoylated in interphase cells but less palmitoylated in mitotic cells. TOFA treatment diminished tubulin palmitoylation at doses that disrupt microtubule (MT) instability and cause spindle defects. Moreover, spindle MTs comprised of α-tubulins mutated at the reported palmitoylation site exhibited disrupted dynamic instability. We also found that TOFA enhanced the MT-targeting drug-induced spindle abnormalities and cytotoxicity. Thus, our study reveals that precise regulation of ACC during mitosis impacts tubulin palmitoylation to delicately control MT dynamic instability and spindle assembly, thereby safeguarding nuclear and cell division.
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Affiliation(s)
- Chieh-Ting Fang
- grid.506933.a0000 0004 0633 7835Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Hsiao-Hui Kuo
- grid.506933.a0000 0004 0633 7835Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Oyundari Amartuvshin
- grid.506933.a0000 0004 0633 7835Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan ,grid.28665.3f0000 0001 2287 1366Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan ,grid.260565.20000 0004 0634 0356Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan
| | - Hwei-Jan Hsu
- grid.506933.a0000 0004 0633 7835Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan ,grid.28665.3f0000 0001 2287 1366Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan ,grid.260565.20000 0004 0634 0356Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan
| | - Sih-Long Liu
- grid.506933.a0000 0004 0633 7835Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Jhong-Syuan Yao
- grid.506933.a0000 0004 0633 7835Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Ling-Huei Yih
- grid.506933.a0000 0004 0633 7835Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
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4
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Kuo HH, Su ZR, Chuang JY, Yih LH. Heat shock factor 1 suppression induces spindle abnormalities and sensitizes cells to antimitotic drugs. Cell Div 2021; 16:8. [PMID: 34922589 PMCID: PMC8684068 DOI: 10.1186/s13008-021-00075-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 11/19/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Heat shock factor 1 (HSF1) is the master regulator of the heat shock response and supports malignant cell transformation. Recent work has shown that HSF1 can access the promoters of heat shock proteins (HSPs) and allow HSP expression during mitosis. It also acts as a mitotic regulator, controlling chromosome segregation. In this study, we investigated whether the transactivation activity of HSF1 is required for the assembly of mitotic spindles. RESULTS Our results showed that phosphorylation of HSF1 at serine 326 (S326) and its transactivation activity were increased during mitosis. Inhibition of the transactivation activity of HSF1 by KRIBB11 or CCT251263 during mitosis significantly increased the proportion of mitotic cells with abnormal spindles. It also hampered the reassembly of spindle microtubules after nocodazole treatment and washout by impeding the formation of chromosomal microtubule asters. Depletion of HSF1 led to defects in mitotic spindle assembly, subsequently attenuating cell proliferation and anchorage-independent cell growth (AIG). These HSF1 depletion-induced effects could be rescued by ectopically expressing wild-type HSF1 or a constitutively active mutant (∆202-316, caHSF1) but not the S326A or dominant negative (∆361-529, dnHSF1) mutants. In addition, overexpression of HSP70 partially reduced HSF1 depletion-induced spindle abnormalities. These results indicate that HSF1 may support cell proliferation and AIG by maintaining spindle integrity through its transactivation activity. Furthermore, inhibition of HSF1 transactivation activity by KRIBB11 or CCT251236 can enhance diverse anti-mitosis drug-induced spindle defects and cell death. CONCLUSIONS The increased transactivation activity of HSF1 during mitosis appears to be required for accurate assembly of mitotic spindles, thereby supporting cell viability and probably AIG. In addition, inhibition of the transactivation activity of HSF1 may enhance the mitotic errors and cell death induced by anti-mitosis drugs.
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Affiliation(s)
- Hsiao-Hui Kuo
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 115, Taiwan
| | - Zhi-Rou Su
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 115, Taiwan.,Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan
| | - Jing-Yuan Chuang
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan
| | - Ling-Huei Yih
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, 115, Taiwan.
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5
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Roles of RACK1 in centrosome regulation and carcinogenesis. Cell Signal 2021; 90:110207. [PMID: 34843916 DOI: 10.1016/j.cellsig.2021.110207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/22/2022]
Abstract
Receptor for activated C kinase 1 (RACK1) regulates various cellular functions and signaling pathways by interacting with different proteins. Recently, we showed that RACK1 interacts with breast cancer gene 1 (BRCA1), which regulates centrosome duplication. RACK1 localizes to centrosomes and spindle poles and is involved in the proper centrosomal localization of BRCA1. The interaction between RACK1 and BRCA1 is critical for the regulation of centrosome number. In addition, RACK1 contributes to centriole duplication by regulating polo-like kinase 1 (PLK1) activity in S phase. RACK1 binds directly to PLK1 and Aurora A, promoting the phosphorylation of PLK1 and activating the Aurora A/PLK1 signaling axis. Overexpression of RACK1 causes centrosome amplification, especially in mammary gland epithelial cells, inducing overactivation of PLK1 followed by premature centriole disengagement and centriole re-duplication. Other proteins, including hypoxia-inducible factor α, von Hippel-Lindau protein, heat-shock protein 90, β-catenin, and glycogen synthase kinase-3β, interact with RACK1 and play roles in centrosome regulation. In this review, we focus on the roles and underlying molecular mechanisms of RACK1 in centrosome regulation mediated by its interaction with different proteins and the modulation of their functions.
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6
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Schweizer N, Haren L, Dutto I, Viais R, Lacasa C, Merdes A, Lüders J. Sub-centrosomal mapping identifies augmin-γTuRC as part of a centriole-stabilizing scaffold. Nat Commun 2021; 12:6042. [PMID: 34654813 PMCID: PMC8519919 DOI: 10.1038/s41467-021-26252-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 09/22/2021] [Indexed: 11/08/2022] Open
Abstract
Centriole biogenesis and maintenance are crucial for cells to generate cilia and assemble centrosomes that function as microtubule organizing centers (MTOCs). Centriole biogenesis and MTOC function both require the microtubule nucleator γ-tubulin ring complex (γTuRC). It is widely accepted that γTuRC nucleates microtubules from the pericentriolar material that is associated with the proximal part of centrioles. However, γTuRC also localizes more distally and in the centriole lumen, but the significance of these findings is unclear. Here we identify spatially and functionally distinct subpopulations of centrosomal γTuRC. Luminal localization is mediated by augmin, which is linked to the centriole inner scaffold through POC5. Disruption of luminal localization impairs centriole integrity and interferes with cilium assembly. Defective ciliogenesis is also observed in γTuRC mutant fibroblasts from a patient suffering from microcephaly with chorioretinopathy. These results identify a non-canonical role of augmin-γTuRC in the centriole lumen that is linked to human disease.
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Affiliation(s)
- Nina Schweizer
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), 08028, Barcelona, Spain
| | - Laurence Haren
- Molecular, Cellular and Developmental Biology, Centre de Biologie Intégrative, CNRS-Université Toulouse III, 31062, Toulouse, France
| | - Ilaria Dutto
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), 08028, Barcelona, Spain
| | - Ricardo Viais
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), 08028, Barcelona, Spain
| | - Cristina Lacasa
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), 08028, Barcelona, Spain
| | - Andreas Merdes
- Molecular, Cellular and Developmental Biology, Centre de Biologie Intégrative, CNRS-Université Toulouse III, 31062, Toulouse, France
| | - Jens Lüders
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), 08028, Barcelona, Spain.
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7
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Abstract
Centrioles are microtubule-based cylindrical structures that assemble the centrosome and template the formation of cilia. The proximal part of centrioles is associated with the pericentriolar material, a protein scaffold from which microtubules are nucleated. This activity is mediated by the γ-tubulin ring complex (γTuRC) whose central role in centrosomal microtubule organization has been recognized for decades. However, accumulating evidence suggests that γTuRC activity at this organelle is neither restricted to the pericentriolar material nor limited to microtubule nucleation. Instead, γTuRC is found along the entire centriole cylinder, at subdistal appendages, and inside the centriole lumen, where its canonical function as a microtubule nucleator might be supplemented or replaced by a function in microtubule anchoring and centriole stabilization, respectively. In this Opinion, we discuss recent insights into the expanded repertoire of γTuRC activities at centrioles and how distinct subpopulations of γTuRC might act in concert to ensure centrosome and cilia biogenesis and function, ultimately supporting cell proliferation, differentiation and homeostasis. We propose that the classical view of centrosomal γTuRC as a pericentriolar material-associated microtubule nucleator needs to be revised.
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Affiliation(s)
- Nina Schweizer
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Jens Lüders
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain
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8
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Mdivi-1 induces spindle abnormalities and augments taxol cytotoxicity in MDA-MB-231 cells. Cell Death Discov 2021; 7:118. [PMID: 34016960 PMCID: PMC8137698 DOI: 10.1038/s41420-021-00495-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/03/2021] [Accepted: 04/23/2021] [Indexed: 01/19/2023] Open
Abstract
Taxol is a first-line chemotherapeutic for numerous cancers, including the highly refractory triple-negative breast cancer (TNBC). However, it is often associated with toxic side effects and chemoresistance in breast cancer patients, which greatly limits the clinical utility of the drug. Hence, compounds that act in concert with taxol to promote cytotoxicity may be useful to improve the efficacy of taxol-based chemotherapy. In this study, we demonstrated that mdivi-1, a putative inhibitor of mitochondrial fission protein Drp1, enhances the anticancer effects of taxol and overcomes taxol resistance in a TNBC cell line (MDA-MB-231). Not only did mdivi-1 induce mitotic spindle abnormalities and mitotic arrest when used alone, but it also enhanced taxol-induced antimitotic effects when applied in combination. In addition, mdivi-1 induced pronounced spindle abnormalities and cytotoxicity in a taxol-resistant cell line, indicating that it can overcome taxol resistance. Notably, the antimitotic effects of mdivi-1 were not accompanied by prominent morphological or functional alterations in mitochondria and were Drp1-independent. Instead, mdivi-1 exhibited affinity to tubulin at μM level, inhibited tubulin polymerization, and immediately disrupted spindle assembly when cells entered mitosis. Together, our results show that mdivi-1 associates with tubulin and impedes tubulin polymerization, actions which may underlie its antimitotic activity and its ability to enhance taxol cytotoxicity and overcome taxol resistance in MDA-MB-231 cells. Furthermore, our data imply a possibility that mdivi-1 could be useful to improve the therapeutic efficacy of taxol in breast cancer.
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9
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Tabara M, Shiraishi K, Takii R, Fujimoto M, Nakai A, Matsuyama H. Testicular localization of activating transcription factor 1 and its potential function during spermatogenesis. Biol Reprod 2021; 105:976-986. [PMID: 34007999 DOI: 10.1093/biolre/ioab099] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/16/2021] [Accepted: 05/14/2021] [Indexed: 12/13/2022] Open
Abstract
Activating transcription factor 1 (ATF1), belonging to the CREB/ATF family of transcription factors, is highly expressed in the testes. However, its role in spermatogenesis has not yet been established. Here, we aimed to elucidate the impact of ATF1 in spermatogenesis by examining the expression pattern of ATF1 in mice and the effect of ATF1 knockdown in the mouse testes. We found that ATF1 is expressed in various organs, with very high levels in the testes. Immunohistochemical staining showed that ATF1 was localized in the nuclei of spermatogonia and co-localized with proliferating cell nuclear antigen. In ATF1-deficient mice, the seminiferous tubules of the testis contained cells at all developmental stages; however, the number of spermatocytes was decreased. Proliferating cell nuclear antigen expression was decreased and apoptotic cells were rare in the seminiferous tubules. These results indicate that ATF1 plays a role in male germ cell proliferation and sperm production.
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Affiliation(s)
- Masanori Tabara
- Department of Urology, School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan.,Department of Biochemistry and Molecular Biology, School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan
| | - Koji Shiraishi
- Department of Urology, School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan
| | - Ryosuke Takii
- Department of Biochemistry and Molecular Biology, School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan
| | - Mitsuaki Fujimoto
- Department of Biochemistry and Molecular Biology, School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan
| | - Akira Nakai
- Department of Biochemistry and Molecular Biology, School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan
| | - Hideyasu Matsuyama
- Department of Urology, School of Medicine, Yamaguchi University, Ube, Yamaguchi 755-8505, Japan
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10
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Lee KS, Park JE, Ahn JI, Zeng Y. Constructing PCM with architecturally distinct higher-order assemblies. Curr Opin Struct Biol 2020; 66:66-73. [PMID: 33176265 DOI: 10.1016/j.sbi.2020.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/23/2020] [Accepted: 09/28/2020] [Indexed: 02/02/2023]
Abstract
Pericentriolar material (PCM) present around a pair of centrioles functions as a platform for various cellular processes, including microtubule (MT) assembly. While PCM is known to be an electron-dense proteinaceous matrix made of long coiled-coil proteins and their client molecules, the molecular mechanism underlying PCM organization remains largely elusive. A growing body of evidence suggests that PCM is constructed in part by an interphase cylindrical self-assembly and the mitotic mesh-like architectures surrounding it. In this review, we will discuss how these higher-order structures are constructed to achieve the functional proficiency of the centrosome.
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Affiliation(s)
- Kyung S Lee
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Jung-Eun Park
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jong Il Ahn
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yan Zeng
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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11
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Fang CT, Kuo HH, Hsu SC, Yih LH. HSP70 regulates Eg5 distribution within the mitotic spindle and modulates the cytotoxicity of Eg5 inhibitors. Cell Death Dis 2020; 11:715. [PMID: 32873777 PMCID: PMC7462862 DOI: 10.1038/s41419-020-02919-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 02/06/2023]
Abstract
The heat shock protein 70 (HSP70) is a conserved molecular chaperone and proteostasis regulator that protects cells from pharmacological stress and promotes drug resistance in cancer cells. In this study, we found that HSP70 may promote resistance to anticancer drugs that target the mitotic kinesin, Eg5, which is essential for assembly and maintenance of the mitotic spindle and cell proliferation. Our data show that loss of HSP70 activity enhances Eg5 inhibitor-induced cytotoxicity and spindle abnormalities. Furthermore, HSP70 colocalizes with Eg5 in the mitotic spindle, and inhibition of HSP70 disrupts this colocalization. Inhibition or depletion of HSP70 also causes Eg5 to accumulate at the spindle pole, altering microtubule dynamics and leading to chromosome misalignment. Using ground state depletion microscopy followed by individual molecule return (GSDIM), we found that HSP70 inhibition reduces the size of Eg5 ensembles and prevents their localization to the inter-polar region of the spindle. In addition, bis(maleimido)hexane-mediated protein-protein crosslinking and proximity ligation assays revealed that HSP70 inhibition deregulates the interaction between Eg5 tetramers and TPX2 at the spindle pole, leading to their accumulation in high-molecular-weight complexes. Finally, we showed that the passive substrate-binding activity of HSP70 is required for appropriate Eg5 distribution and function. Together, our results show that HSP70 substrate-binding activity may regulate proper assembly of Eg5 ensembles and Eg5-TPX2 complexes to modulate mitotic distribution/function of Eg5. Thus, HSP70 inhibition may sensitize cancer cells to Eg5 inhibitor-induced cytotoxicity.
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Affiliation(s)
- Chieh-Ting Fang
- Department of Life Science, National Taiwan University, Taipei, Taiwan.,Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Hsiao-Hui Kuo
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Shao-Chun Hsu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Ling-Huei Yih
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
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Hu Z, Zheng L, Huang J, Zhou L, Liu C, Liu H. Ustiloxin A is Produced Early in Experimental Ustilaginoidea virens Infection and Affects Transcription in Rice. Curr Microbiol 2020; 77:2766-2774. [PMID: 32529481 DOI: 10.1007/s00284-020-02072-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/03/2020] [Indexed: 01/14/2023]
Abstract
Ustiloxin is a kind of 13-membered cyclic peptides found in mature rice false smut generated by Ustilaginoidea virens infecting rice spikelet. So far, six kinds of ustiloxins have been identified from false smut balls (FSBs) in which ustiloxin A is the main component. The toxins can not only inhibit the growth of rice, wheat, and corn, but also poison people and animals. However, so far, there have been few studies of the content of ustiloxin except that in mature FSB. The effect of ustiloxins on the process of infection has not been clarified. In this study, the technique of artificial inoculation coupled with UPLC-ESI-MS was introduced to investigate the content of ustiloxins in the course of infection. The initial formation time of ustiloxin A, B, C, D, F, and G was no later than 5, 5, 9, 7, 7, and 9 days post inoculation (dpi) prior to FSB's formation, respectively. The content of ustiloxin A per spikelet was increased rapidly from 6.0 ng at 5 dpi to 14,157.1 ng at 25 dpi. Meanwhile, the content of ustiloxin A per dry weight (DW) of the FSBs also peaked at 1321.2 μg/g at 25 dpi. Interestingly, both the contents of ustiloxin A per dry weight and per spikelet were significantly reduced from 25 to 30 dpi. Transcriptome sequencing revealed that a total of 146 transcripts (103 upregulated and 43 downregulated) were significantly changed in rice spikelets after 3-h acute exposure to 100 ng ustiloxin A. In addition, several of the significantly altered genes were validated by RT-qPCR.
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Affiliation(s)
- Zheng Hu
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Lu Zheng
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Junbin Huang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Ligang Zhou
- College of Plant Protection, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Chunsheng Liu
- College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China
| | - Hao Liu
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China.
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