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Li Z, Ji W, Hu Q, Zhu P, Jin Y, Duan G. Current status of Merkel cell carcinoma: Epidemiology, pathogenesis and prognostic factors. Virology 2024; 599:110186. [PMID: 39098121 DOI: 10.1016/j.virol.2024.110186] [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: 04/28/2024] [Revised: 07/09/2024] [Accepted: 07/20/2024] [Indexed: 08/06/2024]
Abstract
Merkel cell carcinoma (MCC) is an extremely rare cutaneous neuroendocrine cancer, with an incidence approximately 40 times lower than that of malignant melanoma; however, its significantly inferior survival rate compared to melanoma establishes MCC as the most lethal form of skin cancer. In recent years, a substantial body of literature has demonstrated a gradual increase in the incidence of MCC. Although the two factors that contribute to MCC, ultraviolet radiation and Merkel cell polyomavirus infection, have been well established, the specific pathogenesis of this disease remains unclear. Additionally, considering the high lethality and recurrence rates of MCC, as well as the absence of specific antitumor drugs, it is crucial to elucidate the factors that can accurately predict patients' outcomes. In this review, we summarized the significant advancements in the epidemiological characteristics, pathogenesis, and the factors that influence patient prognosis of MCC to enhance clinical practices and public health efforts.
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Affiliation(s)
- Zijie Li
- Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Wangquan Ji
- Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Quanman Hu
- Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Peiyu Zhu
- Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, 450001, China
| | - Yuefei Jin
- Children's Hospital Affiliated to Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, 450018, China.
| | - Guangcai Duan
- Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou, 450001, China.
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2
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Joshi JN, Lerner AD, Scallo F, Grumet AN, Matteson P, Millonig JH, Valvezan AJ. mTORC1 activity oscillates throughout the cell cycle, promoting mitotic entry and differentially influencing autophagy induction. Cell Rep 2024; 43:114543. [PMID: 39067023 DOI: 10.1016/j.celrep.2024.114543] [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: 02/16/2024] [Revised: 06/07/2024] [Accepted: 07/09/2024] [Indexed: 07/30/2024] Open
Abstract
Mechanistic Target of Rapamycin Complex 1 (mTORC1) is a master metabolic regulator that is active in nearly all proliferating eukaryotic cells; however, it is unclear whether mTORC1 activity changes throughout the cell cycle. We find that mTORC1 activity oscillates from lowest in mitosis/G1 to highest in S/G2. The interphase oscillation is mediated through the TSC complex but is independent of major known regulatory inputs, including Akt and Mek/Erk signaling. By contrast, suppression of mTORC1 activity in mitosis does not require the TSC complex. mTORC1 has long been known to promote progression through G1. We find that mTORC1 also promotes progression through S and G2 and is important for satisfying the Chk1/Wee1-dependent G2/M checkpoint to allow entry into mitosis. We also find that low mTORC1 activity in G1 sensitizes cells to autophagy induction in response to partial mTORC1 inhibition or reduced nutrient levels. Together, these findings demonstrate that mTORC1 is differentially regulated throughout the cell cycle, with important phase-specific consequences for proliferating cells.
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Affiliation(s)
- Jay N Joshi
- Molecular Biosciences Program, Rutgers University, Piscataway, NJ, USA; Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
| | - Ariel D Lerner
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
| | - Frank Scallo
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
| | | | - Paul Matteson
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
| | - James H Millonig
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA; Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Alexander J Valvezan
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA; Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA; Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.
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3
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Pedersen EA, Verhaegen ME, Joseph MK, Harms KL, Harms PW. Merkel cell carcinoma: updates in tumor biology, emerging therapies, and preclinical models. Front Oncol 2024; 14:1413793. [PMID: 39136002 PMCID: PMC11317257 DOI: 10.3389/fonc.2024.1413793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Accepted: 07/08/2024] [Indexed: 08/15/2024] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma thought to arise via either viral (Merkel cell polyomavirus) or ultraviolet-associated pathways. Surgery and radiotherapy have historically been mainstays of management, and immunotherapy has improved outcomes for advanced disease. However, there remains a lack of effective therapy for those patients who fail to respond to these established approaches, underscoring a critical need to better understand MCC biology for more effective prognosis and treatment. Here, we review the fundamental aspects of MCC biology and the recent advances which have had profound impact on management. The first genetically-engineered mouse models for MCC tumorigenesis provide opportunities to understand the potential MCC cell of origin and may prove useful for preclinical investigation of novel therapeutics. The MCC cell of origin debate has also been advanced by recent observations of MCC arising in association with a clonally related hair follicle tumor or squamous cell carcinoma in situ. These studies also suggested a role for epigenetics in the origin of MCC, highlighting a potential utility for this therapeutic avenue in MCC. These and other therapeutic targets form the basis for a wealth of ongoing clinical trials to improve MCC management. Here, we review these recent advances in the context of the existing literature and implications for future investigations.
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Affiliation(s)
| | | | - Mallory K. Joseph
- Department of Dermatology, University of Michigan, Ann Arbor, MI, United States
| | - Kelly L. Harms
- Department of Dermatology, University of Michigan, Ann Arbor, MI, United States
| | - Paul W. Harms
- Department of Dermatology, University of Michigan, Ann Arbor, MI, United States
- Department of Pathology, University of Michigan, Ann Arbor, MI, United States
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Thevenin KR, Tieche IS, Di Benedetto CE, Schrager M, Dye KN. The small tumor antigen of Merkel cell polyomavirus accomplishes cellular transformation by uniquely localizing to the nucleus despite the absence of a known nuclear localization signal. Virol J 2024; 21:125. [PMID: 38831469 PMCID: PMC11149282 DOI: 10.1186/s12985-024-02395-x] [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: 01/19/2024] [Accepted: 05/22/2024] [Indexed: 06/05/2024] Open
Abstract
BACKGROUND Merkel Cell Carcinoma (MCC) is an aggressive skin cancer that is three times deadlier than melanoma. In 2008, it was found that 80% of MCC cases are caused by the genomic integration of a novel polyomavirus, Merkel Cell Polyomavirus (MCPyV), and the expression of its small and truncated large tumor antigens (ST and LT-t, respectively). MCPyV belongs to a family of human polyomaviruses; however, it is the only one with a clear association to cancer. METHODS To investigate the role and mechanisms of various polyomavirus tumor antigens in cellular transformation, Rat-2 and 293A cells were transduced with pLENTI MCPyV LT-t, MCPyV ST, TSPyV ST, HPyV7 ST, or empty pLENTI and assessed through multiple transformation assays, and subcellular fractionations. One-way ANOVA tests were used to assess statistical significance. RESULTS Soft agar, proliferation, doubling time, glucose uptake, and serum dependence assays confirmed ST to be the dominant transforming protein of MCPyV. Furthermore, it was found that MCPyV ST is uniquely transforming, as the ST antigens of other non-oncogenic human polyomaviruses such as Trichodysplasia Spinulosa-Associated Polyomavirus (TSPyV) and Human Polyomavirus 7 (HPyV7) were not transforming when similarly assessed. Identification of structural dissimilarities between transforming and non-transforming tumor antigens revealed that the uniquely transforming domain(s) of MCPyV ST are likely located within the structurally dissimilar loops of the MCPyV ST unique region. Of all known MCPyV ST cellular interactors, 62% are exclusively or transiently nuclear, suggesting that MCPyV ST localizes to the nucleus despite the absence of a canonical nuclear localization signal. Indeed, subcellular fractionations confirmed that MCPyV ST could achieve nuclear localization through a currently unknown, regulated mechanism independent of its small size, as HPyV7 and TSPyV ST proteins were incapable of nuclear translocation. Although nuclear localization was found to be important for several transforming properties of MCPyV ST, some properties were also performed by a cytoplasmic sequestered MCPyV ST, suggesting that MCPyV ST may perform different transforming functions in individual subcellular compartments. CONCLUSIONS Together, these data further elucidate the unique differences between MCPyV ST and other polyomavirus ST proteins necessary to understand MCPyV as the only known human oncogenic polyomavirus.
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Affiliation(s)
- Kaira R Thevenin
- Department of Health Sciences, Stetson University, 421 N Woodland Blvd, DeLand, FL, 32723, USA
| | - Isabella S Tieche
- Department of Health Sciences, Stetson University, 421 N Woodland Blvd, DeLand, FL, 32723, USA
| | - Cody E Di Benedetto
- Department of Health Sciences, Stetson University, 421 N Woodland Blvd, DeLand, FL, 32723, USA
| | - Matt Schrager
- Department of Health Sciences, Stetson University, 421 N Woodland Blvd, DeLand, FL, 32723, USA
| | - Kristine N Dye
- Department of Health Sciences, Stetson University, 421 N Woodland Blvd, DeLand, FL, 32723, USA.
- Department of Biology, Stetson University, DeLand, FL, 32723, USA.
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Li C, Yi Y, Ouyang Y, Chen F, Lu C, Peng S, Wang Y, Chen X, Yan X, Xu H, Li S, Feng L, Xie X. TORSEL, a 4EBP1-based mTORC1 live-cell sensor, reveals nutrient-sensing targeting by histone deacetylase inhibitors. Cell Biosci 2024; 14:68. [PMID: 38824577 PMCID: PMC11143692 DOI: 10.1186/s13578-024-01250-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 05/21/2024] [Indexed: 06/03/2024] Open
Abstract
BACKGROUND Mammalian or mechanistic target of rapamycin complex 1 (mTORC1) is an effective therapeutic target for diseases such as cancer, diabetes, aging, and neurodegeneration. However, an efficient tool for monitoring mTORC1 inhibition in living cells or tissues is lacking. RESULTS We developed a genetically encoded mTORC1 sensor called TORSEL. This sensor changes its fluorescence pattern from diffuse to punctate when 4EBP1 dephosphorylation occurs and interacts with eIF4E. TORSEL can specifically sense the physiological, pharmacological, and genetic inhibition of mTORC1 signaling in living cells and tissues. Importantly, TORSEL is a valuable tool for imaging-based visual screening of mTORC1 inhibitors. Using TORSEL, we identified histone deacetylase inhibitors that selectively block nutrient-sensing signaling to inhibit mTORC1. CONCLUSIONS TORSEL is a unique living cell sensor that efficiently detects the inhibition of mTORC1 activity, and histone deacetylase inhibitors such as panobinostat target mTORC1 signaling through amino acid sensing.
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Affiliation(s)
- Canrong Li
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Yuguo Yi
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Yingyi Ouyang
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Fengzhi Chen
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Chuxin Lu
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Shujun Peng
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Yifan Wang
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Xinyu Chen
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Xiao Yan
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Haolun Xu
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China
| | - Shuiming Li
- College of Life Sciences and Oceanography, Shenzhen Key Laboratory of Microbial Genetic Engineering, Shenzhen University, Shenzhen, China
| | - Lin Feng
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xiaoduo Xie
- School of Medicine, Shenzhen Campus of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China.
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China.
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6
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Millward DJ. Post-natal muscle growth and protein turnover: a narrative review of current understanding. Nutr Res Rev 2024; 37:141-168. [PMID: 37395180 DOI: 10.1017/s0954422423000124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
A model explaining the dietary-protein-driven post-natal skeletal muscle growth and protein turnover in the rat is updated, and the mechanisms involved are described, in this narrative review. Dietary protein controls both bone length and muscle growth, which are interrelated through mechanotransduction mechanisms with muscle growth induced both from stretching subsequent to bone length growth and from internal work against gravity. This induces satellite cell activation, myogenesis and remodelling of the extracellular matrix, establishing a growth capacity for myofibre length and cross-sectional area. Protein deposition within this capacity is enabled by adequate dietary protein and other key nutrients. After briefly reviewing the experimental animal origins of the growth model, key concepts and processes important for growth are reviewed. These include the growth in number and size of the myonuclear domain, satellite cell activity during post-natal development and the autocrine/paracrine action of IGF-1. Regulatory and signalling pathways reviewed include developmental mechanotransduction, signalling through the insulin/IGF-1-PI3K-Akt and the Ras-MAPK pathways in the myofibre and during mechanotransduction of satellite cells. Likely pathways activated by maximal-intensity muscle contractions are highlighted and the regulation of the capacity for protein synthesis in terms of ribosome assembly and the translational regulation of 5-TOPmRNA classes by mTORC1 and LARP1 are discussed. Evidence for and potential mechanisms by which volume limitation of muscle growth can occur which would limit protein deposition within the myofibre are reviewed. An understanding of how muscle growth is achieved allows better nutritional management of its growth in health and disease.
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Affiliation(s)
- D Joe Millward
- Department of Nutritional Sciences, School of Biosciences & Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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7
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Basier C, Nurse P. TOR regulates variability of protein synthesis rates. EMBO J 2024; 43:1618-1633. [PMID: 38499788 PMCID: PMC11021518 DOI: 10.1038/s44318-024-00075-8] [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: 10/23/2023] [Revised: 02/20/2024] [Accepted: 02/23/2024] [Indexed: 03/20/2024] Open
Abstract
Cellular processes are subject to inherent variability, but the extent to which cells can regulate this variability has received little investigation. Here, we explore the characteristics of the rate of cellular protein synthesis in single cells of the eukaryote fission yeast. Strikingly, this rate is highly variable despite protein synthesis being dependent on hundreds of reactions which might be expected to average out at the overall cellular level. The rate is variable over short time scales, and exhibits homoeostatic behaviour at the population level. Cells can regulate the level of variability through processes involving the TOR pathway, suggesting there is an optimal level of variability conferring a selective advantage. While this could be an example of bet-hedging, but we propose an alternative explanation: regulated 'loose' control of complex processes of overall cellular metabolism such as protein synthesis, may lead to this variability. This could ensure cells are fluid in control and agile in response to changing conditions, and may constitute a novel organisational principle of complex metabolic cellular systems.
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Affiliation(s)
- Clovis Basier
- Cell Cycle Laboratory, The Francis Crick Institute, London, NW1 1AT, UK.
| | - Paul Nurse
- Cell Cycle Laboratory, The Francis Crick Institute, London, NW1 1AT, UK
- Laboratory of Yeast Genetics and Cell Biology, Rockefeller University, New York, NY, 10065, USA
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8
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Joshi JN, Lerner AD, Scallo F, Grumet AN, Matteson P, Millonig JH, Valvezan AJ. mTORC1 activity oscillates throughout the cell cycle promoting mitotic entry and differentially influencing autophagy induction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579216. [PMID: 38370755 PMCID: PMC10871213 DOI: 10.1101/2024.02.06.579216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Mechanistic Target of Rapamycin Complex 1 (mTORC1) is a master metabolic regulator that stimulates anabolic cell growth while suppressing catabolic processes such as autophagy. mTORC1 is active in most, if not all, proliferating eukaryotic cells. However, it remains unclear whether and how mTORC1 activity changes from one cell cycle phase to another. Here we tracked mTORC1 activity through the complete cell cycle and uncover oscillations in its activity. We find that mTORC1 activity peaks in S and G2, and is lowest in mitosis and G1. We further demonstrate that multiple mechanisms are involved in controlling this oscillation. The interphase oscillation is mediated through the TSC complex, an upstream negative regulator of mTORC1, but is independent of major known regulatory inputs to the TSC complex, including Akt, Mek/Erk, and CDK4/6 signaling. By contrast, suppression of mTORC1 activity in mitosis does not require the TSC complex, and instead involves CDK1-dependent control of the subcellular localization of mTORC1 itself. Functionally, we find that in addition to its well-established role in promoting progression through G1, mTORC1 also promotes progression through S and G2, and is important for satisfying the Wee1- and Chk1- dependent G2/M checkpoint to allow entry into mitosis. We also find that low mTORC1 activity in G1 sensitizes cells to autophagy induction in response to partial mTORC1 inhibition or reduced nutrient levels. Together these findings demonstrate that mTORC1 is differentially regulated throughout the cell cycle, with important phase-specific functional consequences in proliferating cells.
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Affiliation(s)
- Jay N. Joshi
- Molecular Biosciences Program, Rutgers University, Piscataway, NJ, USA
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
| | - Ariel D. Lerner
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
| | - Frank Scallo
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
- Present affiliation: Yale School of Medicine, New Haven, CT, USA
| | | | - Paul Matteson
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
| | - James H. Millonig
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
- Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | - Alexander J. Valvezan
- Center for Advanced Biotechnology and Medicine, Piscataway, NJ, USA
- Department of Pharmacology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, USA
- Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA
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9
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Chen J, Wang W, Li S, Wang Z, Zuo W, Nong T, Li Y, Liu H, Wei P, He X. RNA-seq reveals role of cell-cycle regulating genes in the pathogenicity of a field very virulent infectious bursal disease virus. Front Vet Sci 2024; 11:1334586. [PMID: 38362295 PMCID: PMC10867150 DOI: 10.3389/fvets.2024.1334586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/10/2024] [Indexed: 02/17/2024] Open
Abstract
Infectious bursal disease virus (IBDV) infection causes highly contagious and immunosuppressive disease in poultry. The thymus, serving as the primary organ for T cell maturation and differentiation, plays an important role in the pathogenicity of IBDV in the infected chickens. However, there are no reports on the molecular pathogenesis of IBDV in the thymus currently. The aim of the study was to elucidate the molecular mechanisms underlying the pathogenicity of a field very virulent (vv) IBDV strain NN1172 in the thymus of SPF chickens using integrative transcriptomic and proteomic analyses. Our results showed that a total of 4,972 Differentially expressed genes (DEGs) in the thymus of NN1172-infected chickens by transcriptomic analysis, with 2,796 up-regulated and 2,176 down-regulated. Meanwhile, the proteomic analysis identified 726 differentially expressed proteins (DEPs) in the infected thymus, with 289 up-regulated and 437 down-regulated. Overall, a total of 359 genes exhibited differentially expression at both mRNA and protein levels, with 134 consistently up-regulated and 198 genes consistently down-regulated, as confirmed through a comparison of the RNA-seq and the proteomic datasets. The gene ontology (GO) analysis unveiled the involvement of both DEGs and DEPs in diverse categories encompassing cellular components, biological processes, and molecular functions in the pathological changes in IBDV-infected thymus. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the host mainly displayed severely disruption of cell survival/repair, proliferation and metabolism pathway, meanwhile, the infection triggers antiviral immune activation with a potential emphasis on the MDA5 pathway. Network inference analysis identified seven core hub genes, which include CDK1, TYMS, MCM5, KIF11, CCNB2, MAD2L1, and MCM4. These genes are all associated with cell-cycle regulating pathway and are likely key mediators in the pathogenesis induced by NN1172 infection in the thymus. This study discovered dominant pathways and genes which enhanced our understanding of the molecular mechanisms underlying IBDV pathogenesis in the thymus.
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Affiliation(s)
- Jinnan Chen
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Weiwei Wang
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Shangquan Li
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Zhiyuan Wang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Wenbo Zuo
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Tingbin Nong
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Yihai Li
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Hongquan Liu
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
| | - Ping Wei
- Institute for Poultry Science and Health, Guangxi University, Nanning, China
| | - Xiumiao He
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi Minzu University, Nanning, China
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10
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Fahim SA, ElZohairy YA, Moustafa RI. Favipiravir, an antiviral drug, in combination with tamoxifen exerts synergistic effect in tamoxifen-resistant breast cancer cells via hTERT inhibition. Sci Rep 2024; 14:1844. [PMID: 38246945 PMCID: PMC10800350 DOI: 10.1038/s41598-024-51977-w] [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: 05/08/2022] [Accepted: 01/10/2024] [Indexed: 01/23/2024] Open
Abstract
Tamoxifen (TAM) is one of the most successful treatments for breast cancer; however, TAM resistance continues to be a significant barrier. TAM resistance has been reported to be associated with increased expression of human telomerase reverse transcriptase (hTERT). This enzyme shares structural similarity with RNA-dependent RNA polymerase (RdRp) enzyme of RNA viruses, suggesting that RdRp inhibitors may also inhibit hTERT. Favipiravir (FAV) is an antiviral drug that inhibits RdRp of RNA viruses. Thus, we propose that FAV may also elicit an antitumor effect by suppressing hTERT. This study aimed to investigate the effect of FAV and TAM on TAM-resistant breast cancer (TAMR-1). The cell viabilities were determined. The levels of CDK1/ hTERT, in addition to regulators of hTERT-targeted signaling pathways were measured. Apoptosis, migration, and cell cycle distribution were also determined. Our data revealed that the combination of TAM and FAV suppressed cell proliferation synergistically (CI < 1) and resulted in a significant change in cell migration and apoptosis. Indeed, this was associated with reduced levels of hTERT and CDK1 and shift in the cell cycle distribution. Our findings suggest that the TAM/FAV combination exhibits synergistic effects against TAMR-1 human breast cancer cells by targeting hTERT.
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Affiliation(s)
- Sally A Fahim
- Department of Biochemistry, School of Pharmacy, Newgiza University (NGU), Newgiza, Km 22 Cairo-Alexandria Desert Road, 6th of October, P.O. Box 12577, Giza, Egypt.
| | - Yehia A ElZohairy
- School of Pharmacy, Newgiza University (NGU), Newgiza, Km 22 Cairo-Alexandria Desert Road, P.O. Box 12577, Giza, Egypt
| | - Rehab I Moustafa
- Microbial Biotechnology Department, Biotechnology Research Institute, National Research Centre, Dokki, Giza, Egypt
- Microbiology Department, School of Pharmacy, Newgiza University (NGU), Newgiza, Km 22 Cairo-Alexandria Desert Road, P.O. Box 12577, Giza, Egypt
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11
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Thevenin KR, Tieche IS, Di Benedetto CE, Schrager M, Dye KN. The Small Tumor Antigen of Merkel Cell Polyomavirus Accomplishes Cellular Transformation by Uniquely Localizing to the Nucleus Despite the Absence of a Known Nuclear Localization Signal. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.28.569067. [PMID: 38293082 PMCID: PMC10827104 DOI: 10.1101/2023.11.28.569067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Background Merkel Cell Carcinoma (MCC) is an aggressive skin cancer that is three times deadlier than melanoma. In 2008, it was found that 80% of MCC cases are caused by the genomic integration of a novel polyomavirus, Merkel Cell Polyomavirus (MCPyV), and the expression of its small and truncated large tumor antigens (ST and LT-t, respectively). MCPyV belongs to a family of human polyomaviruses; however, it is the only one with a clear association to cancer. Methods To investigate the role and mechanisms of various polyomavirus tumor antigens in cellular transformation, Rat-2, 293A, and human foreskin fibroblasts were transduced with pLENTI MCPyV LT-t, MCPyV ST, TSPyV ST, HPyV7 ST, or empty pLENTI and assessed through multiple transformation assays, and subcellular fractionations. One-way ANOVA tests were used to assess statistical significance. Results Soft agar, proliferation, doubling time, glucose uptake, and serum dependence assays confirmed ST to be the dominant transforming protein of MCPyV. Furthermore, it was found that MCPyV ST is uniquely transforming, as the ST antigens of other non-oncogenic human polyomaviruses such as Trichodysplasia Spinulosa Polyomavirus (TSPyV) and Human Polyomavirus 7 (HPyV7) were not transforming when similarly assessed. Identification of structural dissimilarities between transforming and non-transforming tumor antigens revealed that the uniquely transforming domain(s) of MCPyV ST are likely located within the structurally dissimilar loops of the MCPyV ST unique region. Of all known MCPyV ST cellular interactors, 62% are exclusively or transiently nuclear, suggesting that MCPyV ST localizes to the nucleus despite the absence of a canonical nuclear localization signal. Indeed, subcellular fractionations confirmed that MCPyV ST could achieve nuclear localization through a currently unknown, regulated mechanism independent of its small size, as HPyV7 and TSPyV ST proteins were incapable of nuclear translocation. Although nuclear localization was found to be important for several transforming properties of MCPyV ST, some properties were also performed by a cytoplasmic sequestered MCPyV ST, suggesting that MCPyV ST may perform different transforming functions in individual subcellular compartments. Conclusions Together, these data further elucidate the unique differences between MCPyV ST and other polyomavirus ST proteins necessary to understand MCPyV as the only known human oncogenic polyomavirus.
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Xu Y, Wang Y, Chen Q, Yao T, Qiu J, Ni L, Chen H, Liang T. A protein-based prognostic model for pancreatic ductal adenocarcinoma: Construction and validation. Pancreatology 2023; 23:1003-1013. [PMID: 37923686 DOI: 10.1016/j.pan.2023.10.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023]
Abstract
BACKGROUND Probing relevant proteomic biomarkers may facilitate effective pancreatic adenocarcinoma (PDAC) diagnosis, treatment and prevention. Here, we developed a protein-based prognostic model for PDAC by using relevant proteomic biomarkers data from The Cancer Genome Atlas (TCGA). METHODS We obtained PDAC's proteomic and clinical data from TCGA and used various analytical tools to identify differentially expressed proteins between normal and cancer tissues. We constructed our protein-based prognostic model and confirmed its accuracy using receiver operating characteristic curve and Kaplan-Meier survival analyses. We elucidated clinical factor-signature protein correlations by clinical correlation assessments and protein coexpression networks. We also used immunohistochemistry (protein expression assessment), Gene Set Enrichment Analysis (protein role identification) and CIBERSORT (infiltrating immune cell distribution assessment). RESULTS CIITA, BRAF_pS445, AR, YTHDF2, IGFBP2 and CDK1_pT14 were identified as PDAC-associated prognostic proteins. All risk scores calculated using our model provided 1-, 3-, 5-year survival probability at 70 % accuracy. The reliability of our model was validated by the GEO as well. In high- and low-risk groups, age, sex, T- and N- stage disparities were significant, and prognostic and coexpressed proteins correlated. PDAC tissues demonstrated significant CDK1_pT14 overexpression but significant BRAF_pS445, YTHDF2, and IGFBP2 underexpression. Downstream proteins of BRAF were validated by IHC. Low-risk tissues demonstrated more naïve B cells, eosinophils, activated NK cells and regulatory T cells, whereas high-risk tissues demonstrated more activated memory T cells, monocytes, neutrophils, dendritic cells and resting NK cells. CONCLUSIONS Our protein-based prognostic model for PDAC, along with six signature proteins, might aid in predicting PDAC prognosis and therapeutic targets.
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Affiliation(s)
- Yonghao Xu
- Laboratory of Animal Research Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou, 310003, China
| | - Yisu Wang
- Zhejiang Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Qi Chen
- Laboratory of Animal Research Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China; Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou, 310003, China; Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Tao Yao
- College of Life Sciences, Zhejiang Chinese Medical University, Hangzhou, 310053, China
| | - Junyu Qiu
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou, 310003, China; Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Lei Ni
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou, 310003, China; Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Hui Chen
- Laboratory of Animal Research Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China
| | - Tingbo Liang
- Zhejiang Provincial Key Laboratory of Pancreatic Disease, Hangzhou, 310003, China; Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.
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Sun R, Guo S, Shuda Y, Chakka AB, Rigatti LH, Zhao G, Ali MAE, Park CY, Chandran U, Yu J, Bakkenist CJ, Shuda M, Moore PS, Chang Y. Mitotic CDK1 and 4E-BP1 I: Loss of 4E-BP1 serine 82 phosphorylation promotes proliferative polycystic disease and lymphoma in aged or sublethally irradiated mice. PLoS One 2023; 18:e0282722. [PMID: 37145994 PMCID: PMC10162543 DOI: 10.1371/journal.pone.0282722] [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: 10/20/2022] [Accepted: 02/21/2023] [Indexed: 05/07/2023] Open
Abstract
4E-BP1 is a tumor suppressor regulating cap-dependent translation that is in turn controlled by mechanistic target of rapamycin (mTOR) or cyclin-dependent kinase 1 (CDK1) phosphorylation. 4E-BP1 serine 82 (S82) is phosphorylated by CDK1, but not mTOR, and the consequences of this mitosis-specific phosphorylation are unknown. Knock-in mice were generated with a single 4E-BP1 S82 alanine (S82A) substitution leaving other phosphorylation sites intact. S82A mice were fertile and exhibited no gross developmental or behavioral abnormalities, but the homozygotes developed diffuse and severe polycystic liver and kidney disease with aging, and lymphoid malignancies after irradiation. Sublethal irradiation caused immature T-cell lymphoma only in S82A mice while S82A homozygous mice have normal T-cell hematopoiesis before irradiation. Whole genome sequencing identified PTEN mutations in S82A lymphoma and impaired PTEN expression was verified in S82A lymphomas derived cell lines. Our study suggests that the absence of 4E-BP1S82 phosphorylation, a subtle change in 4E-BP1 phosphorylation, might predispose to polycystic proliferative disease and lymphoma under certain stressful circumstances, such as aging and irradiation.
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Affiliation(s)
- Rui Sun
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Siying Guo
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Yoko Shuda
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Anish B. Chakka
- Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Lora H. Rigatti
- Division of Laboratory Animal Resources, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, United States of America
| | - Guangyi Zhao
- Department of Pathology, University of Pittsburgh School of Medicine, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Mohammed A. E. Ali
- Department of Pathology, NYU Grossman School of Medicine, Perlmutter Cancer Center, New York, New York, United States of America
| | - Christopher Y. Park
- Department of Pathology, NYU Grossman School of Medicine, Perlmutter Cancer Center, New York, New York, United States of America
| | - Uma Chandran
- Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jian Yu
- Department of Pathology, University of Pittsburgh School of Medicine, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Christopher J. Bakkenist
- Radiation Oncology, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Masahiro Shuda
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Patrick S. Moore
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Yuan Chang
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
- Department of Pathology, University of Pittsburgh School of Medicine, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
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Xiong Z, Wang M, Wu J, Shi X. Tceal7 Regulates Skeletal Muscle Development through Its Interaction with Cdk1. Int J Mol Sci 2023; 24:ijms24076264. [PMID: 37047236 PMCID: PMC10094454 DOI: 10.3390/ijms24076264] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/23/2023] [Accepted: 03/25/2023] [Indexed: 03/29/2023] Open
Abstract
We have previously reported Tceal7 as a muscle-specific gene that represses myoblast proliferation and promotes myogenic differentiation. The regulatory mechanism of Tceal7 gene expression has been well clarified recently. However, the underlying mechanism of Tceal7 function in skeletal muscle development remains to be elucidated. In the present study, we have generated an MCK 6.5 kb-HA-Tceal7 transgenic model. The transgenic mice are born normally, while they have displayed defects in the growth of body weight and skeletal muscle myofiber during postnatal development. Although four RxL motifs have been identified in the Tceal7 protein sequence, we have not detected any direct protein-protein interaction between Tceal7 and Cyclin A2, Cyclin B1, Cylin D1, or Cyclin E1. Further analysis has revealed the interaction between Tceal7 and Cdk1 instead of Cdk2, Cdk4, or Cdk6. Transgenic overexpression of Tceal7 reduces phosphorylation of 4E-BP1 Ser65, p70S6K1 Thr389, and Cdk substrates in skeletal muscle. In summary, these studies have revealed a novel mechanism of Tceal7 in skeletal muscle development.
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Cao S, Jurczak MJ, Shuda Y, Sun R, Shuda M, Chang Y, Moore PS. Mitotic CDK1 and 4E-BP1 II: A single phosphomimetic mutation in 4E-BP1 induces glucose intolerance in mice. PLoS One 2023; 18:e0282914. [PMID: 36897840 PMCID: PMC10004604 DOI: 10.1371/journal.pone.0282914] [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: 09/18/2022] [Accepted: 02/24/2023] [Indexed: 03/11/2023] Open
Abstract
OBJECTIVE Cyclin-dependent kinase 1 (CDK1)/cyclin B1 phosphorylates many of the same substrates as mTORC1 (a key regulator of glucose metabolism), including the eukaryotic initiation factor 4E-binding protein 1 (4E-BP1). Only mitotic CDK1 phosphorylates 4E-BP1 at residue S82 in mice (S83 in humans), in addition to the common 4E-BP1 phospho-acceptor sites phosphorylated by both CDK1 and mTORC1. We examined glucose metabolism in mice having a single aspartate phosphomimetic amino acid knock in substitution at the 4E-BP1 serine 82 (4E-BP1S82D) mimicking constitutive CDK1 phosphorylation. METHODS Knock-in homozygous 4E-BP1S82D and 4E-BP1S82A C57Bl/6N mice were assessed for glucose tolerance testing (GTT) and metabolic cage analysis on regular and on high-fat chow diets. Gastrocnemius tissues from 4E-BP1S82D and WT mice were subject to Reverse Phase Protein Array analysis. Since the bone marrow is one of the few tissues typically having cycling cells that transit mitosis, reciprocal bone-marrow transplants were performed between male 4E-BP1S82D and WT mice, followed by metabolic assessment, to determine the role of actively cycling cells on glucose homeostasis. RESULTS Homozygous knock-in 4E-BP1S82D mice showed glucose intolerance that was markedly accentuated with a diabetogenic high-fat diet (p = 0.004). In contrast, homozygous mice with the unphosphorylatable alanine substitution (4E-BP1S82A) had normal glucose tolerance. Protein profiling of lean muscle tissues, largely arrested in G0, did not show protein expression or signaling changes that could account for these results. Reciprocal bone-marrow transplantation between 4E-BP1S82D and wild-type littermates revealed a trend for wild-type mice with 4E-BP1S82D marrow engraftment on high-fat diets to become hyperglycemic after glucose challenge. CONCLUSIONS 4E-BP1S82D is a single amino acid substitution that induces glucose intolerance in mice. These findings indicate that glucose metabolism may be regulated by CDK1 4E-BP1 phosphorylation independent from mTOR and point towards an unexpected role for cycling cells that transit mitosis in diabetic glucose control.
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Affiliation(s)
- Simon Cao
- Hillman Cancer Center, Cancer Virology Program, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Michael J. Jurczak
- Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Yoko Shuda
- Hillman Cancer Center, Cancer Virology Program, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Rui Sun
- Hillman Cancer Center, Cancer Virology Program, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Masahiro Shuda
- Hillman Cancer Center, Cancer Virology Program, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Yuan Chang
- Hillman Cancer Center, Cancer Virology Program, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Patrick S. Moore
- Hillman Cancer Center, Cancer Virology Program, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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Merkel Cell Polyomavirus: Infection, Genome, Transcripts and Its Role in Development of Merkel Cell Carcinoma. Cancers (Basel) 2023; 15:cancers15020444. [PMID: 36672392 PMCID: PMC9857234 DOI: 10.3390/cancers15020444] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/23/2022] [Accepted: 12/27/2022] [Indexed: 01/13/2023] Open
Abstract
The best characterized polyomavirus family member, i.e., simian virus 40 (SV40), can cause different tumors in hamsters and can transform murine and human cells in vitro. Hence, the SV40 contamination of millions of polio vaccine doses administered from 1955-1963 raised fears that this may cause increased tumor incidence in the vaccinated population. This is, however, not the case. Indeed, up to now, the only polyomavirus family member known to be the most important cause of a specific human tumor entity is Merkel cell polyomavirus (MCPyV) in Merkel cell carcinoma (MCC). MCC is a highly deadly form of skin cancer for which the cellular origin is still uncertain, and which appears as two clinically very similar but molecularly highly different variants. While approximately 80% of cases are found to be associated with MCPyV the remaining MCCs carry a high mutational load. Here, we present an overview of the multitude of molecular functions described for the MCPyV encoded oncoproteins and non-coding RNAs, present the available MCC mouse models and discuss the increasing evidence that both, virus-negative and -positive MCC constitute epithelial tumors.
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Kalous J, Aleshkina D. Multiple Roles of PLK1 in Mitosis and Meiosis. Cells 2023; 12:cells12010187. [PMID: 36611980 PMCID: PMC9818836 DOI: 10.3390/cells12010187] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 01/05/2023] Open
Abstract
Cells are equipped with a diverse network of signaling and regulatory proteins that function as cell cycle regulators and checkpoint proteins to ensure the proper progression of cell division. A key regulator of cell division is polo-like kinase 1 (PLK1), a member of the serine/threonine kinase family that plays an important role in regulating the mitotic and meiotic cell cycle. The phosphorylation of specific substrates mediated by PLK1 controls nuclear envelope breakdown (NEBD), centrosome maturation, proper spindle assembly, chromosome segregation, and cytokinesis. In mammalian oogenesis, PLK1 is essential for resuming meiosis before ovulation and for establishing the meiotic spindle. Among other potential roles, PLK1 regulates the localized translation of spindle-enriched mRNAs by phosphorylating and thereby inhibiting the translational repressor 4E-BP1, a downstream target of the mTOR (mammalian target of rapamycin) pathway. In this review, we summarize the functions of PLK1 in mitosis, meiosis, and cytokinesis and focus on the role of PLK1 in regulating mRNA translation. However, knowledge of the role of PLK1 in the regulation of meiosis remains limited.
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Gao J, Yao M, Chang D, Liu J. mTOR (Mammalian Target of Rapamycin): Hitting the Bull's Eye for Enhancing Neurogenesis After Cerebral Ischemia? Stroke 2023; 54:279-285. [PMID: 36321454 DOI: 10.1161/strokeaha.122.040376] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ischemic stroke remains a leading cause of morbidity and disability around the world. The sequelae of serious neurological damage are irreversible due to body's own limited repair capacity. However, endogenous neurogenesis induced by cerebral ischemia plays a critical role in the repair and regeneration of impaired neural cells after ischemic brain injury. mTOR (mammalian target of rapamycin) kinase has been suggested to regulate neural stem cells ability to self-renew and differentiate into proliferative daughter cells, thus leading to improved cell growth, proliferation, and survival. In this review, we summarized the current evidence to support that mTOR signaling pathways may enhance neurogenesis, angiogenesis, and synaptic plasticity following cerebral ischemia, which could highlight the potential of mTOR to be a viable therapeutic target for the treatment of ischemic brain injury.
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Affiliation(s)
- Jiale Gao
- Beijing Key Laboratory of Pharmacology of Chinese Materia Medica, Institute of Basic Medical Sciences of Xiyuan Hospital, China Academy of Chinese Medical Sciences, China (J.G., M.Y., J.L.)
| | - Mingjiang Yao
- Beijing Key Laboratory of Pharmacology of Chinese Materia Medica, Institute of Basic Medical Sciences of Xiyuan Hospital, China Academy of Chinese Medical Sciences, China (J.G., M.Y., J.L.)
| | - Dennis Chang
- NICM Health Research Institute, Western Sydney University, Penrith, Australia (D.C.)
| | - Jianxun Liu
- Beijing Key Laboratory of Pharmacology of Chinese Materia Medica, Institute of Basic Medical Sciences of Xiyuan Hospital, China Academy of Chinese Medical Sciences, China (J.G., M.Y., J.L.)
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Wu W, Yu S, Yu X. Transcription-associated cyclin-dependent kinase 12 (CDK12) as a potential target for cancer therapy. Biochim Biophys Acta Rev Cancer 2023; 1878:188842. [PMID: 36460141 DOI: 10.1016/j.bbcan.2022.188842] [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: 08/16/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 12/05/2022]
Abstract
Cyclin-dependent kinase 12 (CDK12), a transcription-related cyclin dependent kinase (CDK), plays a momentous part in multitudinous biological functions, such as replication, transcription initiation to elongation and termination, precursor mRNA (pre-mRNA) splicing, intron polyadenylation (IPA), and translation. CDK12 can act as a tumour suppressor or oncogene in disparate cellular environments, and its dysregulation likely provokes tumorigenesis. A comprehensive understanding of CDK12 will tremendously facilitate the exploitation of novel tactics for the treatment and precaution of cancer. Currently, CDK12 inhibitors are nonspecific and nonselective, which profoundly hinders the pharmacological target validation and drug exploitation process. Herein, we summarize the newly comprehension of the biological functions of CDK12 with a focus on recently emerged advancements of CDK12-associated therapeutic approaches in cancers.
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Affiliation(s)
- Wence Wu
- Departments of Orthopedics, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Department of Etiology and Carcinogenesis, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Carcinogenesis and Cancer Prevention, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shengji Yu
- Departments of Orthopedics, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Xiying Yu
- Department of Etiology and Carcinogenesis, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; State Key Laboratory of Molecular Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Carcinogenesis and Cancer Prevention, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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Rapchak K, Yagobian SD, Moore J, Khattri M, Shuda M. Merkel cell polyomavirus small T antigen is a viral transcription activator that is essential for viral genome maintenance. PLoS Pathog 2022; 18:e1011039. [PMID: 36574443 PMCID: PMC9829177 DOI: 10.1371/journal.ppat.1011039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/09/2023] [Accepted: 12/01/2022] [Indexed: 12/29/2022] Open
Abstract
Merkel cell polyomavirus (MCV) is a small DNA tumor virus that persists in human skin and causes Merkel cell carcinoma (MCC) in immunocompromised individuals. The multi-functional protein MCV small T (sT) activates viral DNA replication by stabilizing large T (LT) and promotes cell transformation through the LT stabilization domain (LTSD). Using MCVΔsT, a mutant MCV clone that ablates sT, we investigated the role of sT in MCV genome maintenance. sT was dispensable for initiation of viral DNA replication, but essential for maintenance of the MCV genome and activation of viral early and late gene expression for progression of the viral lifecycle. Furthermore, in phenotype rescue studies, exogenous sT activated viral DNA replication and mRNA expression in MCVΔsT through the LTSD. While exogenous LT expression, which mimics LT stabilization, increased viral DNA replication, it did not activate viral mRNA expression. After cataloging transcriptional regulator proteins by proximity-based MCV sT-host protein interaction analysis, we validated LTSD-dependent sT interaction with four transcriptional regulators: Cux1, c-Jun, BRD9, and CBP. Functional studies revealed Cux1 and c-Jun as negative regulators, and CBP and BRD9 as positive regulators of MCV transcription. CBP inhibitor A-485 suppressed sT-induced viral gene activation in replicating MCVΔsT and inhibited early gene expression in MCV-integrated MCC cells. These results suggest that sT promotes viral lifecycle progression by activating mRNA expression and capsid protein production through interaction with the transcriptional regulators. This activity is essential for MCV genome maintenance, suggesting a critical role of sT in MCV persistence and MCC carcinogenesis.
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Affiliation(s)
- Kyle Rapchak
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Shiva D. Yagobian
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Jackson Moore
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Michelle Khattri
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Masahiro Shuda
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
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Targeting the translational machinery in gastrointestinal stromal tumors (GIST): a new therapeutic vulnerability. Sci Rep 2022; 12:8275. [PMID: 35585158 PMCID: PMC9117308 DOI: 10.1038/s41598-022-12000-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 04/27/2022] [Indexed: 01/13/2023] Open
Abstract
Although KIT-mutant GISTs can be effectively treated with tyrosine kinase inhibitors (TKIs), many patients develop resistance to imatinib mesylate (IM) as well as the FDA-approved later-line agents sunitinib, regorafenib and ripretinib. Resistance mechanisms mainly involve secondary mutations in the KIT receptor tyrosine kinase gene indicating continued dependency on the KIT signaling pathway. The fact that the type of secondary mutation confers either sensitivity or resistance towards TKIs and the notion that secondary mutations exhibit intra- and intertumoral heterogeneity complicates the optimal choice of treatment in the imatinib-resistant setting. Therefore, new strategies that target KIT independently of its underlying mutations are urgently needed. Homoharringtonine (HHT) is a first-in-class inhibitor of protein biosynthesis and is FDA-approved for the treatment of chronic myeloid leukemia (CML) that is resistant to at least two TKIs. HHT has also shown activity in KIT-mutant mastocytosis models, which are intrinsically resistant to imatinib and most other TKIs. We hypothesized that HHT could be effective in GIST through downregulation of KIT expression and subsequent decrease of KIT activation and downstream signaling. Testing several GIST cell line models, HHT led to a significant reduction in nascent protein synthesis and was highly effective in the nanomolar range in IM-sensitive and IM-resistant GIST cell lines. HHT treatment resulted in a rapid and complete abolishment of KIT expression and activation, while KIT mRNA levels were minimally affected. The response to HHT involved induction of apoptosis as well as cell cycle arrest. The antitumor activity of HHT was confirmed in a GIST xenograft model. Taken together, inhibition of protein biosynthesis is a promising strategy to overcome TKI resistance in GIST.
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Miettinen TP, Ly KS, Lam A, Manalis SR. Single-cell monitoring of dry mass and dry mass density reveals exocytosis of cellular dry contents in mitosis. eLife 2022; 11:e76664. [PMID: 35535854 PMCID: PMC9090323 DOI: 10.7554/elife.76664] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 04/22/2022] [Indexed: 01/02/2023] Open
Abstract
Cell mass and composition change with cell cycle progression. Our previous work characterized buoyant mass dynamics in mitosis (Miettinen et al., 2019), but how dry mass and cell composition change in mitosis has remained unclear. To better understand mitotic cell growth and compositional changes, we develop a single-cell approach for monitoring dry mass and the density of that dry mass every ~75 s with 1.3% and 0.3% measurement precision, respectively. We find that suspension grown mammalian cells lose dry mass and increase dry mass density following mitotic entry. These changes display large, non-genetic cell-to-cell variability, and the changes are reversed at metaphase-anaphase transition, after which dry mass continues accumulating. The change in dry mass density causes buoyant and dry mass to differ specifically in early mitosis, thus reconciling existing literature on mitotic cell growth. Mechanistically, cells in early mitosis increase lysosomal exocytosis, and inhibition of lysosomal exocytosis decreases the dry mass loss and dry mass density increase in mitosis. Overall, our work provides a new approach for monitoring single-cell dry mass and dry mass density, and reveals that mitosis is coupled to extensive exocytosis-mediated secretion of cellular contents.
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Affiliation(s)
- Teemu P Miettinen
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of TechnologyCambridgeUnited States
- MIT Center for Precision Cancer Medicine, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Kevin S Ly
- Department of Biological Engineering, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Alice Lam
- Department of Biological Engineering, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Scott R Manalis
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of TechnologyCambridgeUnited States
- MIT Center for Precision Cancer Medicine, Massachusetts Institute of TechnologyCambridgeUnited States
- Department of Biological Engineering, Massachusetts Institute of TechnologyCambridgeUnited States
- Department of Mechanical Engineering, Massachusetts Institute of TechnologyCambridgeUnited States
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23
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Differential Sensitivity of the Protein Translation Initiation Machinery and mTOR Signaling to MECP2 Gain- and Loss-of-Function Involves MeCP2 Isoform-Specific Homeostasis in the Brain. Cells 2022; 11:cells11091442. [PMID: 35563748 PMCID: PMC9105805 DOI: 10.3390/cells11091442] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/15/2022] [Accepted: 04/19/2022] [Indexed: 12/25/2022] Open
Abstract
Eukaryotic gene expression is controlled at multiple levels, including gene transcription and protein translation initiation. One molecule with key roles in both regulatory mechanisms is methyl CpG binding protein 2 (MeCP2). MECP2 gain- and loss-of-function mutations lead to Rett Syndrome and MECP2 Duplication Syndrome, respectively. To study MECP2 gain-of-function, we generated stably transduced human brain cells using lentiviral vectors for both MECP2E1 and MECP2E2 isoforms. Stable overexpression was confirmed by Western blot and immunofluorescence. We assessed the impact of MeCP2E1-E2 gain-of-function on the MeCP2 homeostasis regulatory network (MECP2E1/E2-BDNF/BDNF-miR-132), mTOR-AKT signaling, ribosome biogenesis, markers of chromatin structure, and protein translation initiation. We observed that combined co-transduction of MeCP2 isoforms led to protein degradation of MeCP2E1. Proteosome inhibition by MG132 treatment recovered MeCP2E1 protein within an hour, suggesting its induced degradation through the proteosome pathway. No significant change was detected for translation initiation factors as a result of MeCP2E1, MeCP2E2, or combined overexpression of both isoforms. In contrast, analysis of human Rett Syndrome brains tissues compared with controls indicated impaired protein translation initiation, suggesting that such mechanisms may have differential sensitivity to MECP2 gain- and loss-of-function. Collectively, our results provide further insight towards the dose-dependent functional role of MeCP2 isoforms in the human brain.
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24
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Clemm von Hohenberg K, Müller S, Schleich S, Meister M, Bohlen J, Hofmann TG, Teleman AA. Cyclin B/CDK1 and Cyclin A/CDK2 phosphorylate DENR to promote mitotic protein translation and faithful cell division. Nat Commun 2022; 13:668. [PMID: 35115540 PMCID: PMC8813921 DOI: 10.1038/s41467-022-28265-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 01/12/2022] [Indexed: 12/11/2022] Open
Abstract
DENR and MCTS1 have been identified as oncogenes in several different tumor entities. The heterodimeric DENR·MCTS1 protein complex promotes translation of mRNAs containing upstream Open Reading Frames (uORFs). We show here that DENR is phosphorylated on Serine 73 by Cyclin B/CDK1 and Cyclin A/CDK2 at the onset of mitosis, and then dephosphorylated as cells exit mitosis. Phosphorylation of Ser73 promotes mitotic stability of DENR protein and prevents its cleavage at Asp26. This leads to enhanced translation of mRNAs involved in mitosis. Indeed, we find that roughly 40% of all mRNAs with elevated translation in mitosis are DENR targets. In the absence of DENR or of Ser73 phosphorylation, cells display elevated levels of aberrant mitoses and cell death. This provides a mechanism how the cell cycle regulates translation of a subset of mitotically relevant mRNAs during mitosis.
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Affiliation(s)
- Katharina Clemm von Hohenberg
- German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Heidelberg University, 69120, Heidelberg, Germany
- CellNetworks-Cluster of Excellence, Heidelberg University, Heidelberg, Germany
- Department of Medicine III, Universitätsmedizin Mannheim, 68167, Mannheim, Germany
| | - Sandra Müller
- German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Heidelberg University, 69120, Heidelberg, Germany
| | - Sibylle Schleich
- German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Heidelberg University, 69120, Heidelberg, Germany
| | - Matthias Meister
- Division of Viral Transformation Mechanisms, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jonathan Bohlen
- German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany
- Heidelberg University, 69120, Heidelberg, Germany
- CellNetworks-Cluster of Excellence, Heidelberg University, Heidelberg, Germany
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, INSERM U1163, Paris, France
- University of Paris, Imagine Institute, Paris, France
| | - Thomas G Hofmann
- Institute of Toxicology, University Medical Center Mainz at the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), 69120, Heidelberg, Germany.
- Heidelberg University, 69120, Heidelberg, Germany.
- CellNetworks-Cluster of Excellence, Heidelberg University, Heidelberg, Germany.
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25
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Chen C, Zhang X, Wang Y, Chen X, Chen W, Dan S, She S, Hu W, Dai J, Hu J, Cao Q, Liu Q, Huang Y, Qin B, Kang B, Wang YJ. Translational and post-translational control of human naïve versus primed pluripotency. iScience 2022; 25:103645. [PMID: 35005567 PMCID: PMC8718978 DOI: 10.1016/j.isci.2021.103645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 10/22/2021] [Accepted: 12/10/2021] [Indexed: 01/05/2023] Open
Abstract
Deciphering the regulatory network for human naive and primed pluripotency is of fundamental theoretical and applicable significance. Here, by combining quantitative proteomics, phosphoproteomics, and acetylproteomics analyses, we revealed RNA processing and translation as the most differentially regulated processes between naive and primed human embryonic stem cells (hESCs). Although glycolytic primed hESCs rely predominantly on the eukaryotic initiation factor 4E (eIF4E)-mediated cap-dependent pathway for protein translation, naive hESCs with reduced mammalian target of rapamycin complex (mTORC1) activity are more tolerant to eIF4E inhibition, and their bivalent metabolism allows for translating selective mRNAs via both eIF4E-dependent and eIF4E-independent/eIF4A2-dependent pathways to form a more compact naive proteome. Globally up-regulated proteostasis and down-regulated post-translational modifications help to further refine the naive proteome that is compatible with the more rapid cycling of naive hESCs, where CDK1 plays an indispensable coordinative role. These findings may assist in better understanding the unrestricted lineage potential of naive hESCs and in further optimizing conditions for future clinical applications RNA processing and translation are most different between naive and primed hESCs Glycolytic primed hESCs mainly rely on eIF4E-dependent translation Bivalent metabolism in naive hESCs promotes eIF4E-independent translation CDK1 is required for naive pluripotency partially by activating E-cadherin signaling
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Affiliation(s)
- Cheng Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China.,Shaoxing People's Hospital, Shaoxing Hospital, Zhejiang University School of Medicine, Shaoxing, Zhejiang 312000, China
| | - Xiaobing Zhang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Yisha Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Xinyu Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Wenjie Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Songsong Dan
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Shiqi She
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China.,Zhejiang Museum of Natural History, Hangzhou, Zhejiang 310014, China
| | - Weiwei Hu
- Shanghai Bioprofile Technology Co., Ltd., Shanghai 200241, China
| | - Jie Dai
- Shanghai Bioprofile Technology Co., Ltd., Shanghai 200241, China
| | - Jianwen Hu
- Shanghai Bioprofile Technology Co., Ltd., Shanghai 200241, China
| | - Qingyi Cao
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Qianyu Liu
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yinghua Huang
- Laboratory of Metabolism and Cell Fate, Center for Cell Lineage and Development, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Baoming Qin
- Laboratory of Metabolism and Cell Fate, Center for Cell Lineage and Development, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China
| | - Bo Kang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China
| | - Ying-Jie Wang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, China.,Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China
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26
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A genetically-encoded crosslinker screen identifies SERBP1 as a PKCε substrate influencing translation and cell division. Nat Commun 2021; 12:6934. [PMID: 34836941 PMCID: PMC8626422 DOI: 10.1038/s41467-021-27189-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 11/08/2021] [Indexed: 01/09/2023] Open
Abstract
The PKCε-regulated genome protective pathway provides transformed cells a failsafe to successfully complete mitosis. Despite the necessary role for Aurora B in this programme, it is unclear whether its requirement is sufficient or if other PKCε cell cycle targets are involved. To address this, we developed a trapping strategy using UV-photocrosslinkable amino acids encoded in the PKCε kinase domain. The validation of the mRNA binding protein SERBP1 as a PKCε substrate revealed a series of mitotic events controlled by the catalytic form of PKCε. PKCε represses protein translation, altering SERBP1 binding to the 40 S ribosomal subunit and promoting the assembly of ribonucleoprotein granules containing SERBP1, termed M-bodies. Independent of Aurora B, SERBP1 is shown to be necessary for chromosome segregation and successful cell division, correlating with M-body formation. This requirement for SERBP1 demonstrates that Aurora B acts in concert with translational regulation in the PKCε-controlled pathway exerting genome protection.
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27
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Moustafa-Kamal M, Kucharski TJ, El-Assaad W, Abbas YM, Gandin V, Nagar B, Pelletier J, Topisirovic I, Teodoro JG. The mTORC1/S6K/PDCD4/eIF4A Axis Determines Outcome of Mitotic Arrest. Cell Rep 2021; 33:108230. [PMID: 33027666 DOI: 10.1016/j.celrep.2020.108230] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/29/2020] [Accepted: 09/14/2020] [Indexed: 12/26/2022] Open
Abstract
mTOR is a serine/threonine kinase and a master regulator of cell growth and proliferation. Raptor, a scaffolding protein that recruits substrates to mTOR complex 1 (mTORC1), is known to be phosphorylated during mitosis, but the significance of this phosphorylation remains largely unknown. Here we show that raptor expression and mTORC1 activity are dramatically reduced in cells arrested in mitosis. Expression of a non-phosphorylatable raptor mutant reactivates mTORC1 and significantly reduces cytotoxicity of the mitotic poison Taxol. This effect is mediated via degradation of PDCD4, a tumor suppressor protein that inhibits eIF4A activity and is negatively regulated by the mTORC1/S6K pathway. Moreover, pharmacological inhibition of eIF4A is able to enhance the effects of Taxol and restore sensitivity in Taxol-resistant cancer cells. These findings indicate that the mTORC1/S6K/PDCD4/eIF4A axis has a pivotal role in the death versus slippage decision during mitotic arrest and may be exploited clinically to treat tumors resistant to anti-mitotic agents.
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Affiliation(s)
- Mohamed Moustafa-Kamal
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Thomas J Kucharski
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Wissal El-Assaad
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada
| | - Yazan M Abbas
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Valentina Gandin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Bhushan Nagar
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Jerry Pelletier
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Ivan Topisirovic
- Department of Biochemistry, McGill University, Montréal, QC, Canada; Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, and Department of Oncology, McGill University, Montréal, QC, Canada.
| | - Jose G Teodoro
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada.
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28
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Uchiyama J, Ishihama Y, Imami K. Quantitative nascent proteome profiling by dual-pulse labelling with O-propargyl-puromycin and stable isotope-labelled amino acids. J Biochem 2021; 169:227-236. [PMID: 32926143 DOI: 10.1093/jb/mvaa104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/30/2020] [Indexed: 11/13/2022] Open
Abstract
Monitoring translational regulation in response to environmental signals is crucial for understanding cellular proteostasis. However, only limited approaches are currently available for quantifying acute changes in protein synthesis induced by stimuli. Recently, a clickable puromycin analogue, O-propargyl-puromycin (OPP), was developed and applied to label the C-termini of nascent polypeptide chains (NPCs). Following affinity purification via a click reaction, OPP allows for a proteomic analysis of NPCs. Despite its advantage, the affinity purification of NPCs using magnetic beads or resins inherently suffers from significant non-specific protein binding, which hinders accurate quantification of the nascent proteins. To address this issue, we employed dual-pulse labelling of NPCs with both OPP and stable isotope-labelled amino acids to distinguish bona fide NPCs from non-specific proteins, thereby enabling the accurate quantitative profiling of NPCs. We applied this method to dissecting translation responses upon transcriptional inhibition and quantified ∼3,000 nascent proteins. We found that the translation of a subset of ribosomal proteins (e.g. RPSA, RPLP0) as well as signalling proteins (e.g. BCAR3, EFNA1, DUSP1) was significantly repressed by transcription inhibition. Together, the present method provides an accurate and broadly applicable nascent proteome profiling for many biological applications at the level of translation.
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Affiliation(s)
- Junki Uchiyama
- Department of Molecular and Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yasushi Ishihama
- Department of Molecular and Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.,Department of Proteomics and Drug Discovery, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Koshi Imami
- Department of Molecular and Cellular BioAnalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan.,PRESTO, Japan Science and Technology Agency (JST), 5-3 Yonban-cho, Chiyoda-ku, Tokyo 102-0075, Japan
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29
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Githaka JM, Tripathi N, Kirschenman R, Patel N, Pandya V, Kramer DA, Montpetit R, Zhu LF, Sonenberg N, Fahlman RP, Danial NN, Underhill DA, Goping IS. BAD regulates mammary gland morphogenesis by 4E-BP1-mediated control of localized translation in mouse and human models. Nat Commun 2021; 12:2939. [PMID: 34011960 PMCID: PMC8134504 DOI: 10.1038/s41467-021-23269-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 04/20/2021] [Indexed: 02/03/2023] Open
Abstract
Elucidation of non-canonical protein functions can identify novel tissue homeostasis pathways. Herein, we describe a role for the Bcl-2 family member BAD in postnatal mammary gland morphogenesis. In Bad3SA knock-in mice, where BAD cannot undergo phosphorylation at 3 key serine residues, pubertal gland development is delayed due to aberrant tubulogenesis of the ductal epithelium. Proteomic and RPPA analyses identify that BAD regulates focal adhesions and the mRNA translation repressor, 4E-BP1. These results suggest that BAD modulates localized translation that drives focal adhesion maturation and cell motility. Consistent with this, cells within Bad3SA organoids contain unstable protrusions with decreased compartmentalized mRNA translation and focal adhesions, and exhibit reduced cell migration and tubulogenesis. Critically, protrusion stability is rescued by 4E-BP1 depletion. Together our results confirm an unexpected role of BAD in controlling localized translation and cell migration during mammary gland development.
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Affiliation(s)
- John Maringa Githaka
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - Namita Tripathi
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - Raven Kirschenman
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - Namrata Patel
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - Vrajesh Pandya
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - David A. Kramer
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - Rachel Montpetit
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - Lin Fu Zhu
- grid.17089.37Department of Surgery, University of Alberta, Edmonton, AB Canada
| | - Nahum Sonenberg
- grid.14709.3b0000 0004 1936 8649Department of Biochemistry, McGill University, Montreal, QC Canada
| | - Richard P. Fahlman
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada
| | - Nika N. Danial
- grid.65499.370000 0001 2106 9910Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA USA
| | - D. Alan Underhill
- grid.17089.37Department of Oncology, University of Alberta, Edmonton, AB Canada
| | - Ing Swie Goping
- grid.17089.37Department of Biochemistry, University of Alberta, Edmonton, AB Canada ,grid.17089.37Department of Oncology, University of Alberta, Edmonton, AB Canada
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30
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Xiao B, Zuo D, Hirukawa A, Cardiff RD, Lamb R, Sonenberg N, Muller WJ. Rheb1-Independent Activation of mTORC1 in Mammary Tumors Occurs through Activating Mutations in mTOR. Cell Rep 2021; 31:107571. [PMID: 32348753 DOI: 10.1016/j.celrep.2020.107571] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 12/06/2019] [Accepted: 04/02/2020] [Indexed: 11/25/2022] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a master modulator of cellular growth, and its aberrant regulation is recurrently documented within breast cancer. While the small GTPase Rheb1 is the canonical activator of mTORC1, Rheb1-independent mechanisms of mTORC1 activation have also been reported but have not been fully understood. Employing multiple transgenic mouse models of breast cancer, we report that ablation of Rheb1 significantly impedes mammary tumorigenesis. In the absence of Rheb1, a block in tumor initiation can be overcome by multiple independent mutations in Mtor to allow Rheb1-independent reactivation of mTORC1. We further demonstrate that the mTOR kinase is indispensable for tumor initiation as the genetic ablation of mTOR abolishes mammary tumorigenesis. Collectively, our findings demonstrate that mTORC1 activation is indispensable for mammary tumor initiation and that tumors acquire alternative mechanisms of mTORC1 activation.
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Affiliation(s)
- Bin Xiao
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Dongmei Zuo
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Alison Hirukawa
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Robert D Cardiff
- Center for Comparative Medicine, University of California, Davis, Davis, CA 95616, USA
| | | | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Faculty of Medicine, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - William J Muller
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Faculty of Medicine, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada.
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31
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Alboushi L, Hackett AP, Naeli P, Bakhti M, Jafarnejad SM. Multifaceted control of mRNA translation machinery in cancer. Cell Signal 2021; 84:110037. [PMID: 33975011 DOI: 10.1016/j.cellsig.2021.110037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 05/06/2021] [Indexed: 12/15/2022]
Abstract
The mRNA translation machinery is tightly regulated through several, at times overlapping, mechanisms that modulate its efficiency and accuracy. Due to their fast rate of growth and metabolism, cancer cells require an excessive amount of mRNA translation and protein synthesis. However, unfavorable conditions, such as hypoxia, amino acid starvation, and oxidative stress, which are abundant in cancer, as well as many anti-cancer treatments inhibit mRNA translation. Cancer cells adapt to the various internal and environmental stresses by employing specialised transcript-specific translation to survive and gain a proliferative advantage. We will highlight the major signaling pathways and mechanisms of translation that regulate the global or mRNA-specific translation in response to the intra- or extra-cellular signals and stresses that are key components in the process of tumourigenesis.
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Affiliation(s)
- Lilas Alboushi
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Angela P Hackett
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Parisa Naeli
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
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32
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Spevak CC, Elias HK, Kannan L, Ali MAE, Martin GH, Selvaraj S, Eng WS, Ernlund A, Rajasekhar VK, Woolthuis CM, Zhao G, Ha CJ, Schneider RJ, Park CY. Hematopoietic Stem and Progenitor Cells Exhibit Stage-Specific Translational Programs via mTOR- and CDK1-Dependent Mechanisms. Cell Stem Cell 2021; 26:755-765.e7. [PMID: 32386556 DOI: 10.1016/j.stem.2019.12.006] [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: 07/27/2018] [Revised: 08/16/2019] [Accepted: 12/16/2019] [Indexed: 12/11/2022]
Abstract
Hematopoietic stem cells (HSCs) require highly regulated rates of protein synthesis, but it is unclear if they or lineage-committed progenitors preferentially recruit transcripts to translating ribosomes. We utilized polysome profiling, RNA sequencing, and whole-proteomic approaches to examine the translatome in LSK (Lin-Sca-1+c-Kit+) and myeloid progenitor (MP; Lin-Sca-1-c-Kit+) cells. Our studies show that LSKs exhibit low global translation but high translational efficiencies (TEs) of mRNAs required for HSC maintenance. In contrast, MPs activate translation in an mTOR-independent manner due, at least in part, to proteasomal degradation of mTOR by the E3 ubiquitin ligase c-Cbl. In the near absence of mTOR, CDK1 activates eIF4E-dependent translation in MPs through phosphorylation of 4E-BP1. Aberrant activation of mTOR expression and signaling in c-Cbl-deficient MPs results in increased mature myeloid lineage output. Overall, our data demonstrate that hematopoietic stem and progenitor cells (HSPCs) undergo translational reprogramming mediated by previously uncharacterized mechanisms of translational regulation.
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Affiliation(s)
- Christina C Spevak
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Harold K Elias
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Lavanya Kannan
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Mohamed A E Ali
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Gaëlle H Martin
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | | | - William S Eng
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Amanda Ernlund
- Department of Microbiology and Perlmutter Cancer Center, NYU School of Medicine, New York, NY 10016, USA
| | - Vinagolu K Rajasekhar
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Carolien M Woolthuis
- Department of Hematology, Cancer Research Center, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Guangjie Zhao
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Caryn J Ha
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA
| | - Robert J Schneider
- Department of Microbiology and Perlmutter Cancer Center, NYU School of Medicine, New York, NY 10016, USA
| | - Christopher Y Park
- Department of Pathology, NYU School of Medicine, New York, NY 10016, USA.
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33
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Pascual R, Segura-Morales C, Omerzu M, Bellora N, Belloc E, Castellazzi CL, Reina O, Eyras E, Maurice MM, Millanes-Romero A, Méndez R. mRNA spindle localization and mitotic translational regulation by CPEB1 and CPEB4. RNA (NEW YORK, N.Y.) 2020; 27:rna.077552.120. [PMID: 33323527 PMCID: PMC7901846 DOI: 10.1261/rna.077552.120] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 12/02/2020] [Indexed: 05/04/2023]
Abstract
Transition through cell cycle phases requires temporal and spatial regulation of gene expression to ensure accurate chromosome duplication and segregation. This regulation involves dynamic reprogramming of gene expression at multiple transcriptional and posttranscriptional levels. In transcriptionally silent oocytes, the CPEB-family of RNAbinding proteins coordinates temporal and spatial translation regulation of stored maternal mRNAs to drive meiotic progression. CPEB1 mediates mRNA localization to the meiotic spindle, which is required to ensure proper chromosome segregation. Temporal translational regulation also takes place in mitosis, where a large repertoire of transcripts are activated or repressed in specific cell cycle phases. However, whether control of localized translation at the spindle is required for mitosis is unclear, as mitotic and acentriolar-meiotic spindles are functionally and structurally different. Furthermore, the large differences in scale-ratio between cell volume and spindle size in oocytes compared to somatic mitotic cells may generate distinct requirements for gene expression compartmentalization in meiosis and mitosis. Here we show that mitotic spindles contain CPE-localized mRNAs and translating ribosomes. Moreover, CPEB1 and CPEB4 localize in the spindles and they may function sequentially in promoting mitotic stage transitions and correct chromosome segregation. Thus, CPEB1 and CPEB4 bind to specific spindle-associated transcripts controlling the expression and/or localization of their encoded factors that, respectively, drive metaphase and anaphase/cytokinesis.
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Affiliation(s)
- Rosa Pascual
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology
| | - Carolina Segura-Morales
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology
| | - Manja Omerzu
- Oncode Institute and Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht
| | - Nicolás Bellora
- Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales (IPATEC), Universidad Nacional del Comahue - CONICET
| | - Eulàlia Belloc
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology
| | - Chiara Lara Castellazzi
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology
| | - Oscar Reina
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology
| | - Eduardo Eyras
- Department of Experimental and Health Sciences, Universidad Pompeu Fabra
| | - Madelon M Maurice
- Oncode Institute and Department of Cell Biology, Centre for Molecular Medicine, University Medical Centre Utrecht
| | - Alba Millanes-Romero
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology
| | - Raúl Méndez
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology;
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Waldron A, Yajima M. Localized translation on the mitotic apparatus: A history and perspective. Dev Biol 2020; 468:55-58. [PMID: 32979335 DOI: 10.1016/j.ydbio.2020.09.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 09/10/2020] [Accepted: 09/16/2020] [Indexed: 10/23/2022]
Abstract
Localized translation is a proposed biological event that allows mRNA to be translated on site, providing an additional level of protein regulation within a cell. Examples of localized translation have been found or proposed in a variety of cellular contexts from neurons to cancer cells and implicated in both normal development and disease for over a half century. For example, mRNA translation on the mitotic apparatus (MA) was initially hypothesized in the 1950-60s. However, its proof of existence, biological significance and mechanistic details have remained sparse and it is still unclear how well conserved this mechanism may be among different cell types or organisms. In this review, we provide a brief historic summary of translation on the MA and discuss how current and future work may help us understand this biological process that provides a subcellular level of regulation in protein synthesis within a cell.
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Affiliation(s)
- Ashley Waldron
- Department of Molecular Biology Cell Biology Biochemistry, Brown University, 185 Meeting Street, BOX-GL277, Providence, RI 02912, USA
| | - Mamiko Yajima
- Department of Molecular Biology Cell Biology Biochemistry, Brown University, 185 Meeting Street, BOX-GL277, Providence, RI 02912, USA.
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Odle RI, Florey O, Ktistakis NT, Cook SJ. CDK1, the Other 'Master Regulator' of Autophagy. Trends Cell Biol 2020; 31:95-107. [PMID: 33272830 DOI: 10.1016/j.tcb.2020.11.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/30/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022]
Abstract
Autophagy and cap-dependent mRNA translation are tightly regulated by the mechanistic target of rapamycin complex 1 (mTORC1) signalling complex in response to nutrient availability. However, the regulation of these processes, and mTORC1 itself, is different during mitosis, and this has remained an area of significant controversy; for example, studies have argued that autophagy is either repressed or highly active during mitosis. Recent studies have shown that autophagy initiation is repressed, and cap-dependent mRNA translation is maintained during mitosis despite mTORC1 activity being repressed. This is achieved in large part by a switch from mTORC1- to cyclin-dependent kinase 1 (CDK1)-mediated regulation. Here, we review the history and recent advances and seek to present a unifying model to inform the future study of autophagy and mTORC1 during mitosis.
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Affiliation(s)
- Richard I Odle
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Oliver Florey
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Nicholas T Ktistakis
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Simon J Cook
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK.
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36
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Zamfirescu RC, Day ML, Morris MB. mTORC1/2 signaling is downregulated by amino acid-free culture of mouse preimplantation embryos and is only partially restored by amino acid readdition. Am J Physiol Cell Physiol 2020; 320:C30-C44. [PMID: 33052068 DOI: 10.1152/ajpcell.00385.2020] [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] [Indexed: 12/12/2022]
Abstract
Development of the mammalian preimplantation embryo is influenced by autocrine/paracrine factors and the availability of nutrients. Deficiencies of these during in vitro culture reduce the success of assisted reproductive technologies. The mechanistic target of rapamycin complex 1 (mTORC1) pathway integrates external and internal signals, including those by amino acids (AAs), to promote normal preimplantation development. For this reason, AAs are often included in embryo culture media. In this study, we examined how withdrawal and addition of AAs to culture media modulate mTORC1 pathway activity compared with its activity in mouse embryos developed in vivo. Phosphorylation of signaling components downstream of mTORC1, namely, p70 ribosomal protein S6 kinase (p70S6K), ribosomal protein S6, and 4E binding protein 1 (4E-BP1), and that of protein kinase B (Akt), which lies upstream of mTORC1, changed significantly across stages of embryos developed in vivo. For freshly isolated blastocysts placed in vitro, the absence of AAs in the culture medium, even for a few hours, decreased mTORC1 signaling, which could only be partially restored by their addition. Long-term culture of early embryos to blastocysts in the absence of AAs decreased mTORC1 signaling to a greater extent and again this could only be partially restored by their inclusion. This failure to fully restore is probably due to decreased phosphatidylinositol 3-kinase (PI3K)/Akt/mTORC2 signaling in culture, as indicated by decreased P-AktS473. mTORC2 lies upstream of mTORC1 and is insensitive to AAs, and its reduced activity probably results from loss of maternal/autocrine factors. These data highlight reduced mTORC1/2 signaling activity correlating with compromised development in vitro and show that the addition of AAs can only partially offset these effects.
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Affiliation(s)
- Radu C Zamfirescu
- Discipline of Physiology and Bosch Institute, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Margot L Day
- Discipline of Physiology and Bosch Institute, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Michael B Morris
- Discipline of Physiology and Bosch Institute, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Camperdown, New South Wales, Australia
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Translation Regulation by eIF2α Phosphorylation and mTORC1 Signaling Pathways in Non-Communicable Diseases (NCDs). Int J Mol Sci 2020; 21:ijms21155301. [PMID: 32722591 PMCID: PMC7432514 DOI: 10.3390/ijms21155301] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 02/07/2023] Open
Abstract
Non-communicable diseases (NCDs) are medical conditions that, by definition, are non-infectious and non-transmissible among people. Much of current NCDs are generally due to genetic, behavioral, and metabolic risk factors that often include excessive alcohol consumption, smoking, obesity, and untreated elevated blood pressure, and share many common signal transduction pathways. Alterations in cell and physiological signaling and transcriptional control pathways have been well studied in several human NCDs, but these same pathways also regulate expression and function of the protein synthetic machinery and mRNA translation which have been less well investigated. Alterations in expression of specific translation factors, and disruption of canonical mRNA translational regulation, both contribute to the pathology of many NCDs. The two most common pathological alterations that contribute to NCDs discussed in this review will be the regulation of eukaryotic initiation factor 2 (eIF2) by the integrated stress response (ISR) and the mammalian target of rapamycin complex 1 (mTORC1) pathways. Both pathways integrally connect mRNA translation activity to external and internal physiological stimuli. Here, we review the role of ISR control of eIF2 activity and mTORC1 control of cap-mediated mRNA translation in some common NCDs, including Alzheimer’s disease, Parkinson’s disease, stroke, diabetes mellitus, liver cirrhosis, chronic obstructive pulmonary disease (COPD), and cardiac diseases. Our goal is to provide insights that further the understanding as to the important role of translational regulation in the pathogenesis of these diseases.
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Pietropaolo V, Prezioso C, Moens U. Merkel Cell Polyomavirus and Merkel Cell Carcinoma. Cancers (Basel) 2020; 12:E1774. [PMID: 32635198 PMCID: PMC7407210 DOI: 10.3390/cancers12071774] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 12/12/2022] Open
Abstract
Viruses are the cause of approximately 15% of all human cancers. Both RNA and DNA human tumor viruses have been identified, with Merkel cell polyomavirus being the most recent one to be linked to cancer. This virus is associated with about 80% of Merkel cell carcinomas, a rare, but aggressive cutaneous malignancy. Despite its name, the cells of origin of this tumor may not be Merkel cells. This review provides an update on the structure and life cycle, cell tropism and epidemiology of the virus and its oncogenic properties. Putative strategies to prevent viral infection or treat virus-positive Merkel cell carcinoma patients are discussed.
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Affiliation(s)
- Valeria Pietropaolo
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy; (V.P.); (C.P.)
| | - Carla Prezioso
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy; (V.P.); (C.P.)
- IRCSS San Raffaele Pisana, Microbiology of Chronic Neuro-Degenerative Pathologies, 00166 Rome, Italy
| | - Ugo Moens
- Molecular Inflammation Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø—The Arctic University of Norway, 9037 Tromsø, Norway
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Kalous J, Jansová D, Šušor A. Role of Cyclin-Dependent Kinase 1 in Translational Regulation in the M-Phase. Cells 2020; 9:cells9071568. [PMID: 32605021 PMCID: PMC7408968 DOI: 10.3390/cells9071568] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/15/2020] [Accepted: 06/24/2020] [Indexed: 12/20/2022] Open
Abstract
Cyclin dependent kinase 1 (CDK1) has been primarily identified as a key cell cycle regulator in both mitosis and meiosis. Recently, an extramitotic function of CDK1 emerged when evidence was found that CDK1 is involved in many cellular events that are essential for cell proliferation and survival. In this review we summarize the involvement of CDK1 in the initiation and elongation steps of protein synthesis in the cell. During its activation, CDK1 influences the initiation of protein synthesis, promotes the activity of specific translational initiation factors and affects the functioning of a subset of elongation factors. Our review provides insights into gene expression regulation during the transcriptionally silent M-phase and describes quantitative and qualitative translational changes based on the extramitotic role of the cell cycle master regulator CDK1 to optimize temporal synthesis of proteins to sustain the division-related processes: mitosis and cytokinesis.
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40
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Mass measurements during lymphocytic leukemia cell polyploidization decouple cell cycle- and cell size-dependent growth. Proc Natl Acad Sci U S A 2020; 117:15659-15665. [PMID: 32581119 PMCID: PMC7355023 DOI: 10.1073/pnas.1922197117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Cell size is believed to influence cell growth through limited transport efficiency in larger cells. However, this has not been experimentally investigated due to a lack of noninvasive, high-precision growth quantification methods suitable for measuring large cells. Here, we have engineered large versions of microfluidic mass sensors called suspended microchannel resonators in order to study the growth of single mammalian cells that range 100-fold in mass. Our measurements, which decouple growth effects caused by cell cycle and cell size, revealed that absolute cell size does not impose strict transport or other limitations that would inhibit growth and that cell cycle has a large influence on growth. Cell size is believed to influence cell growth and metabolism. Consistently, several studies have revealed that large cells have lower mass accumulation rates per unit mass (i.e., growth efficiency) than intermediate-sized cells in the same population. Size-dependent growth is commonly attributed to transport limitations, such as increased diffusion timescales and decreased surface-to-volume ratio. However, separating cell size- and cell cycle-dependent growth is challenging. To address this, we monitored growth efficiency of pseudodiploid mouse lymphocytic leukemia cells during normal proliferation and polyploidization. This was enabled by the development of large-channel suspended microchannel resonators that allow us to monitor buoyant mass of single cells ranging from 40 pg (small pseudodiploid cell) to over 4,000 pg, with a resolution ranging from ∼1% to ∼0.05%. We find that cell growth efficiency increases, plateaus, and then decreases as cell cycle proceeds. This growth behavior repeats with every endomitotic cycle as cells grow into polyploidy. Overall, growth efficiency changes 33% throughout the cell cycle. In contrast, increasing cell mass by over 100-fold during polyploidization did not change growth efficiency, indicating exponential growth. Consistently, growth efficiency remained constant when cell cycle was arrested in G2. Thus, cell cycle is a primary determinant of growth efficiency. As growth remains exponential over large size scales, our work finds no evidence for transport limitations that would decrease growth efficiency.
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41
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Li Z, Tian X, Ji X, Wang J, Chen H, Wang D, Zhang X. ULK1-ATG13 and their mitotic phospho-regulation by CDK1 connect autophagy to cell cycle. PLoS Biol 2020; 18:e3000288. [PMID: 32516310 PMCID: PMC7282624 DOI: 10.1371/journal.pbio.3000288] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 03/27/2020] [Indexed: 01/08/2023] Open
Abstract
Unc-51-like autophagy activating kinase 1 (ULK1)–autophagy-related 13 (ATG13) is the most upstream autophagy initiation complex that is phosphorylated by mammalian target-of-rapamycin complex 1 (mTORC1) and AMP-activated protein kinase (AMPK) to induce autophagy in asynchronous conditions. However, their phospho-regulation and functions in mitosis and cell cycle remain unknown. Here we show that ULK1-ATG13 complex is differentially regulated throughout the cell cycle, especially in mitosis, in which both ULK1 and ATG13 are highly phosphorylated by the key cell cycle machinery cyclin-dependent kinase 1 (CDK1)/cyclin B. Combining mass spectrometry and site-directed mutagenesis, we found that CDK1-induced ULK1-ATG13 phosphorylation promotes mitotic autophagy and cell cycle progression. Moreover, double knockout (DKO) of ULK1 and ATG13 could block cell cycle progression and significantly decrease cancer cell proliferation in cell line and mouse models. Our results not only bridge the mutual regulation between the core machinery of autophagy and mitosis but also illustrate the positive function of ULK1-ATG13 and their phosphorylation by CDK1 in mitotic autophagy regulation. This study shows that the ULK1-ATG13 autophagy initiation complex is differentially regulated throughout the cell cycle, especially in mitosis, in which both ULK1 and ATG13 are highly phosphorylated by CDK1/cyclin B, promoting mitotic autophagy and cell cycle progression.
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Affiliation(s)
- Zhiyuan Li
- High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
- * E-mail: (XZ); (ZL)
| | - Xiaofei Tian
- High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Xinmiao Ji
- High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Junjun Wang
- High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Hanxiao Chen
- High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Dongmei Wang
- High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
| | - Xin Zhang
- High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, P. R. China
- Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, P. R. China
- * E-mail: (XZ); (ZL)
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42
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Choi SH, Kim S, Jones KA. Gene expression regulation by CDK12: a versatile kinase in cancer with functions beyond CTD phosphorylation. Exp Mol Med 2020; 52:762-771. [PMID: 32451425 PMCID: PMC7272620 DOI: 10.1038/s12276-020-0442-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 04/08/2020] [Accepted: 04/13/2020] [Indexed: 12/21/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) play critical roles in cell cycle progression and gene expression regulation. In human cancer, transcription-associated CDKs can activate oncogenic gene expression programs, whereas cell cycle-regulatory CDKs mainly induce uncontrolled proliferation. Cyclin-dependent kinase 12 (CDK12) belongs to the CDK family of serine/threonine kinases and has been recently found to have multiple roles in gene expression regulation and tumorigenesis. Originally, CDK12 was thought to be one of the transcription-associated CDKs, acting with its cyclin partner Cyclin K to promote the phosphorylation of the C-terminal domain (CTD) of RNA polymerase II and induce transcription elongation. However, recent studies have demonstrated that CDK12 also controls multiple gene expression processes, including transcription termination, mRNA splicing, and translation. Most importantly, CDK12 mutations are frequently found in human tumors. Loss of CDK12 function causes defective expression of DNA damage response (DDR) genes, which eventually results in genome instability, a hallmark of human cancer. Here, we discuss the diverse roles of CDK12 in gene expression regulation and human cancer, focusing on newly identified CDK12 kinase functions in cellular processes and highlighting CDK12 as a promising therapeutic target for human cancer treatment. Better understanding of the roles played by a protein kinase, an enzyme that adds phosphate groups to other molecules, in healthy and diseased states may help scientists identify novel cancer treatments. Cyclin-dependent kinases (CDKs) are a family of protein kinases crucial to cell cycling and gene expression. CDK12 can activate and modulate cancer-related gene expression, but, according to a review by Seung Hyuk Choi and colleagues at the Salk Institute for Biological Studies in La Jolla, USA, further investigations into its exact functioning and control mechanisms are required. CDK12 mutations are frequently found in aggressive breast and ovarian cancers, while loss of CDK12 function results in abnormal expression of DNA damage response genes and genome instability. CDK12 may also regulate drug resistance in cancer cells. The team suggests that therapies targeting CDK12 are worth exploring.
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Affiliation(s)
- Seung Hyuk Choi
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
| | - Seongjae Kim
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Katherine A Jones
- Regulatory Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
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43
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Surface charge of Merkel cell polyomavirus small T antigen determines cell transformation through allosteric FBW7 WD40 domain targeting. Oncogenesis 2020; 9:53. [PMID: 32427880 PMCID: PMC7237485 DOI: 10.1038/s41389-020-0235-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: 02/17/2020] [Revised: 04/27/2020] [Accepted: 04/29/2020] [Indexed: 12/20/2022] Open
Abstract
Merkel cell polyomavirus (MCV) small T (sT) is the main oncoprotein in Merkel cell carcinoma (MCC) development. A unique domain of sT, LT stabilization domain (LSD), has been reported to bind and inactivate multiple SCF (Skp1-Cullin-F-box) E3 ligases. These interactions impede the turnover of MCV large T (LT) antigen and cellular oncoproteins such as c-Myc and cyclin E, thereby promoting viral replication and cell transformation. However, it is currently unclear how this LSD region contributes to multiple transforming activities of sT. Structural docking simulation of sT and F-box and WD repeat domain-containing 7 (FBW7) revealed a novel allosteric interaction between sT and FBW7 WD40 domain. This model is supported by experimental evidence confirming that charge engineering in the LSD alters sT-WD40 binding. Specifically, loss of net positive charge in the LSD prevents sT-FBW7 binding by abrogating the electrostatic interaction, thus impeding inhibition of FBW7 by sT. Furthermore, positively charged mutations in the LSD significantly restored the sT function and its ability to transform rodent fibroblast cells. We infer that the surface charge of sT is a major determinant for targeting E3 ligases, which leads to sT-induced cell transformation, an observation that could be used to develop targeted therapeutics for MCC.
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44
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Kumar S, Xie H, Shi H, Gao J, Juhlin CC, Björnhagen V, Höög A, Lee L, Larsson C, Lui W. Merkel cell polyomavirus oncoproteins induce microRNAs that suppress multiple autophagy genes. Int J Cancer 2020; 146:1652-1666. [PMID: 31180579 PMCID: PMC7003823 DOI: 10.1002/ijc.32503] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 05/09/2019] [Accepted: 05/29/2019] [Indexed: 01/12/2023]
Abstract
Viruses can inhibit host autophagy through multiple mechanisms, and evasion of autophagy plays an important role in immune suppression and viral oncogenesis. Merkel cell polyomavirus (MCPyV) T-antigens are expressed and involved in the pathogenesis of a large proportion of Merkel cell carcinoma (MCC). Yet, how MCPyV induces tumorigenesis is not fully understood. Herein, we show that MCPyV T-antigens induce miR-375, miR-30a-3p and miR-30a-5p expressions, which target multiple key genes involved in autophagy, including ATG7, SQSTM1 (p62) and BECN1. In MCC tumors, low expression of ATG7 and p62 are associated with MCPyV-positive tumors. Ectopic expression of MCPyV small T-antigen and truncated large T-antigen (LT), but not the wild-type LT, resulted in autophagy suppression, suggesting the importance of autophagy evasion in MCPyV-mediated tumorigenesis. Torin-1 treatment induced cell death, which was attenuated by autophagy inhibitor, but not pan-caspase inhibitor, suggesting a potential role of autophagy in promoting cell death in MCC. Conceptually, our study shows that MCPyV oncoproteins suppress autophagy to protect cancer cells from cell death, which contribute to a better understanding of MCPyV-mediated tumorigenesis and potential MCC treatment.
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Affiliation(s)
- Satendra Kumar
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
| | - Hong Xie
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
- Tianjin Life Science Research Center and Department of Pathogen BiologySchool of Basic Medical Sciences, Tianjin Medical UniversityTianjinChina
| | - Hao Shi
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
| | - Jiwei Gao
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
| | - Carl Christofer Juhlin
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
- Department of Clinical Pathology and CytologyKarolinska University HospitalStockholmSweden
| | - Viveca Björnhagen
- Department of Reconstructive Plastic SurgeryKarolinska University HospitalStockholmSweden
| | - Anders Höög
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
- Department of Clinical Pathology and CytologyKarolinska University HospitalStockholmSweden
| | - Linkiat Lee
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
| | - Catharina Larsson
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
- Department of Clinical Pathology and CytologyKarolinska University HospitalStockholmSweden
| | - Weng‐Onn Lui
- Department of Oncology‐PathologyKarolinska Institutet; Cancer Center Karolinska, Karolinska University HospitalStockholmSweden
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45
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Haneke K, Schott J, Lindner D, Hollensen AK, Damgaard CK, Mongis C, Knop M, Palm W, Ruggieri A, Stoecklin G. CDK1 couples proliferation with protein synthesis. J Cell Biol 2020; 219:e201906147. [PMID: 32040547 PMCID: PMC7054999 DOI: 10.1083/jcb.201906147] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 11/20/2019] [Accepted: 01/08/2020] [Indexed: 12/26/2022] Open
Abstract
Cell proliferation exerts a high demand on protein synthesis, yet the mechanisms coupling the two processes are not fully understood. A kinase and phosphatase screen for activators of translation, based on the formation of stress granules in human cells, revealed cell cycle-associated kinases as major candidates. CDK1 was identified as a positive regulator of global translation, and cell synchronization experiments showed that this is an extramitotic function of CDK1. Different pathways including eIF2α, 4EBP, and S6K1 signaling contribute to controlling global translation downstream of CDK1. Moreover, Ribo-Seq analysis uncovered that CDK1 exerts a particularly strong effect on the translation of 5'TOP mRNAs, which includes mRNAs encoding ribosomal proteins and several translation factors. This effect requires the 5'TOP mRNA-binding protein LARP1, concurrent to our finding that LARP1 phosphorylation is strongly dependent on CDK1. Thus, CDK1 provides a direct means to couple cell proliferation with biosynthesis of the translation machinery and the rate of protein synthesis.
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Affiliation(s)
- Katharina Haneke
- Division of Biochemistry, Mannheim Institute for Innate Immunoscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Johanna Schott
- Division of Biochemistry, Mannheim Institute for Innate Immunoscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Doris Lindner
- Division of Biochemistry, Mannheim Institute for Innate Immunoscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Anne Kruse Hollensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | - Cyril Mongis
- Center for Molecular Biology of Heidelberg University, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Michael Knop
- Center for Molecular Biology of Heidelberg University, DKFZ-ZMBH Alliance, Heidelberg, Germany
- Cell Morphogenesis and Signal Transduction, German Cancer Research Center, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Wilhelm Palm
- Cell Signaling and Metabolism, German Cancer Research Center, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Alessia Ruggieri
- Department of Infectious Diseases, Molecular Virology, Center for Integrative Infectious Diseases Research, University of Heidelberg, Heidelberg, Germany
| | - Georg Stoecklin
- Division of Biochemistry, Mannheim Institute for Innate Immunoscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Center for Molecular Biology of Heidelberg University, DKFZ-ZMBH Alliance, Heidelberg, Germany
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46
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Odle RI, Walker SA, Oxley D, Kidger AM, Balmanno K, Gilley R, Okkenhaug H, Florey O, Ktistakis NT, Cook SJ. An mTORC1-to-CDK1 Switch Maintains Autophagy Suppression during Mitosis. Mol Cell 2020; 77:228-240.e7. [PMID: 31733992 PMCID: PMC6964153 DOI: 10.1016/j.molcel.2019.10.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 07/19/2019] [Accepted: 10/10/2019] [Indexed: 01/09/2023]
Abstract
Since nuclear envelope breakdown occurs during mitosis in metazoan cells, it has been proposed that macroautophagy must be inhibited to maintain genome integrity. However, repression of macroautophagy during mitosis remains controversial and mechanistic detail limited to the suggestion that CDK1 phosphorylates VPS34. Here, we show that initiation of macroautophagy, measured by the translocation of the ULK complex to autophagic puncta, is repressed during mitosis, even when mTORC1 is inhibited. Indeed, mTORC1 is inactive during mitosis, reflecting its failure to localize to lysosomes due to CDK1-dependent RAPTOR phosphorylation. While mTORC1 normally represses autophagy via phosphorylation of ULK1, ATG13, ATG14, and TFEB, we show that the mitotic phosphorylation of these autophagy regulators, including at known repressive sites, is dependent on CDK1 but independent of mTOR. Thus, CDK1 substitutes for inhibited mTORC1 as the master regulator of macroautophagy during mitosis, uncoupling autophagy regulation from nutrient status to ensure repression of macroautophagy during mitosis.
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Affiliation(s)
- Richard I Odle
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
| | - Simon A Walker
- Imaging Facility, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - David Oxley
- Proteomics Facility, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Andrew M Kidger
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Kathryn Balmanno
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Rebecca Gilley
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Hanneke Okkenhaug
- Imaging Facility, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Oliver Florey
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Nicholas T Ktistakis
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Simon J Cook
- Signalling Laboratory, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
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47
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Mitchell DC, Menon A, Garner AL. Cyclin-dependent kinase 4 inhibits the translational repressor 4E-BP1 to promote cap-dependent translation during mitosis-G1 transition. FEBS Lett 2019; 594:1307-1318. [PMID: 31853978 DOI: 10.1002/1873-3468.13721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 01/18/2023]
Abstract
Phosphorylation of translational repressor eukaryotic translation initiation factor 4E (eIF4E)-binding protein 1 (4E-BP1) controls the initiation of cap-dependent translation, a type of protein synthesis that is frequently upregulated in human diseases such as cancer. Because of its critical cellular function, it is not surprising that multiple kinases can post-translationally modify 4E-BP1 to drive aberrant cap-dependent translation. We recently reported a site-selective chemoproteomic method for uncovering kinase-substrate interactions, and using this approach, we discovered the cyclin-dependent kinase (CDK)4 as a new 4E-BP1 kinase. Herein, we describe our extension of this work and reveal the role of CDK4 in modulating 4E-BP1 activity in the transition from mitosis to G1, thereby demonstrating a novel role for this kinase in cell cycle regulation.
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Affiliation(s)
- Dylan C Mitchell
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, USA
| | - Arya Menon
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA
| | - Amanda L Garner
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, USA.,Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI, USA
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48
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An T, Liu Y, Gourguechon S, Wang CC, Li Z. CDK Phosphorylation of Translation Initiation Factors Couples Protein Translation with Cell-Cycle Transition. Cell Rep 2019; 25:3204-3214.e5. [PMID: 30540951 PMCID: PMC6350937 DOI: 10.1016/j.celrep.2018.11.063] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/18/2018] [Accepted: 11/15/2018] [Indexed: 01/17/2023] Open
Abstract
Protein translation in eukaryotes is cell-cycle dependent, with translation rates more robust in G1 phase of the cell cycle than in mitosis. However, whether the fundamental cell-cycle control machinery directly activates protein translation during the G1/S cell-cycle transition remains unknown. Using the early divergent eukaryote Trypanosoma brucei as a model organism, we report that the G1 cyclin-dependent kinase CRK1 phosphorylates two translation initiation factors, eIF4E4 and PABP1, to promote the G1/S cell-cycle transition and global protein translation. Phosphorylation of eIF4E4 by CRK1 enhances binding to the m7G cap structure and interaction with eIF4E4 and eIF4G3, and phosphorylation of PABP1 by CRK1 promotes association with the poly(A) sequence, self-interaction, and interaction with eIF4E4. These findings demonstrate that cyclin-dependent kinase-mediated regulation of translation initiation factors couples global protein translation with the G1/S cell-cycle transition. Protein translation is cell-cycle dependent, with more robust translation rates in the G1 phase of the cell cycle than in mitosis. An et al. show that the G1 cyclin-dependent kinase CRK1 phosphorylates translation initiation factors eIF4E4 and PABP1 to couple protein translation initiation with the G1/S cell-cycle transition.
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Affiliation(s)
- Tai An
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yi Liu
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Stéphane Gourguechon
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ching C Wang
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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49
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Spatio-temporal expression of ANK2 promotes cytokinesis in oocytes. Sci Rep 2019; 9:13121. [PMID: 31511568 PMCID: PMC6739377 DOI: 10.1038/s41598-019-49483-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 08/21/2019] [Indexed: 01/01/2023] Open
Abstract
In the absence of transcription, the regulation of gene expression in oocytes is controlled almost exclusively at the level of transcriptome and proteome stabilization, and translation. A subset of maternal transcripts is stored in a translationally dormant state in the oocyte, and temporally driven translation of specific mRNAs propel meiotic progression, oocyte-to-embryo transition and early embryo development. We identified Ank2.3 as the only transcript variant present in the mouse oocyte and discovered that it is translated after nuclear envelope breakdown. Here we show that Ank2.3 mRNA is localized in higher concentration in the oocyte nucleoplasm and, after nuclear envelope breakdown, in the newly forming spindle where its translation occurs. Furthermore, we reveal that Ank2.3 mRNA contains an oligo-pyrimidine motif at 5'UTR that predetermines its translation through a cap-dependent pathway. Lastly, we show that prevention of ANK2 translation leads to abnormalities in oocyte cytokinesis.
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50
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Boye E, Grallert B. eIF2α phosphorylation and the regulation of translation. Curr Genet 2019; 66:293-297. [PMID: 31485739 DOI: 10.1007/s00294-019-01026-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 12/27/2022]
Abstract
We discuss novel insight into the role and consequences of the phosphorylation of the translation initiation factor eIF2α in the context of stress responses and cell-cycle regulation. eIF2α is centrally located to regulate translation and its phosphorylation in response to different environmental challenges is one of the best characterized stress-response pathways. In addition to its role in stress management, eIF2α phosphorylation is also linked to cell-cycle progression and memory consolidation in the nervous system. The best known consequences of eIF2α phosphorylation are downregulation of global translation and stimulation of translation of some mRNAs. However, recent evidence shows that (i) eIF2α phosphorylation is not always required for the downregulation of global translation after exposure to stress and (ii) eIF2α phosphorylation does not necessarily lead to the downregulation of global translation. These results suggest that the textbook view of eIF2α phosphorylation needs to be revised and that there must be additional regulatory mechanisms at play.
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Affiliation(s)
- Erik Boye
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Beáta Grallert
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway.
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