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Fan H, Zhou Z, Zheng W, Guan Y, Meng Q, Wang W, Dong J, Wan L, Zhu J, Zeng Y, Liu R, Gu H, Lin G, Chen B, Sang Q, Wang L. Homozygous variants in CDC23 cause female infertility characterized by oocyte maturation defects. Hum Genet 2023; 142:1621-1631. [PMID: 37768355 DOI: 10.1007/s00439-023-02606-5] [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: 06/04/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023]
Abstract
Oocyte maturation defects are major phenotypes resulting in female infertility. Although many genetic factors have been found to be responsible for these phenotypes, the underlying pathogenic genes and variants remain to be identified. The anaphase promoting complex or cyclosome (APC/C) is known to be essential in the metaphase-to-anaphase transition. In this study, we identified two homozygous missense variants (c.986A > G, p.Y329C and c.988C > T, p.R330C) in CDC23 that are responsible for female infertility characterized by oocyte maturation defects in three infertile individuals. CDC23 (cell division cycle 23) is one of the core subunits of the APC/C. In vitro experiments showed that the variant c.986A > G (p.Y329C) led to a decrease in CDC23 protein level and the variant c.988C > T (p.R330C) changed the localization of CDC23 in HeLa cells and mouse oocytes. In vivo studies showed that Cdc23Y329C/Y329C mice successfully mimicked the patients' phenotype by causing low expression of CDC23 and APC4 and the accumulation of securin and cyclin B1 in oocytes. AZ3146 treatment was able to rescue the phenotype. Taken together, our findings reveal the important roles of CDC23 in human oocyte maturation and provide a new genetic marker for female infertility.
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Affiliation(s)
- Huizhen Fan
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Zhou Zhou
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
- NHC Key Lab of Reproduction Regulation, Shanghai Engineering Research Center of Reproductive Health Drug and Devices, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai, 200237, China
| | - Wei Zheng
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, 410078, China
| | - Yichun Guan
- Department of Reproductive Medicine, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Qingxia Meng
- Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, 215000, China
| | - Wenjing Wang
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Jie Dong
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Liuxia Wan
- Department of Reproductive Medicine, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Jiawei Zhu
- Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, 215000, China
| | - Yang Zeng
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Ruyi Liu
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Hao Gu
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Ge Lin
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, 410078, China
| | - Biaobang Chen
- NHC Key Lab of Reproduction Regulation, Shanghai Engineering Research Center of Reproductive Health Drug and Devices, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Shanghai, 200237, China.
| | - Qing Sang
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China.
| | - Lei Wang
- Institute of Pediatrics, Children's Hospital of Fudan University, the Institutes of Biomedical Sciences, the State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China.
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Malavašič P, Polajžer S, Lovšin N. Anaphase-Promoting Complex Subunit 1 Associates with Bone Mineral Density in Human Osteoporotic Bone. Int J Mol Sci 2023; 24:12895. [PMID: 37629076 PMCID: PMC10454667 DOI: 10.3390/ijms241612895] [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: 07/14/2023] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
Genome-wide association studies (GWAS) are one of the most common approaches to identify genetic loci that are associated with bone mineral density (BMD). Such novel genetic loci represent new potential targets for the prevention and treatment of fragility fractures. GWAS have identified hundreds of associations with BMD; however, only a few have been functionally evaluated. A locus significantly associated with femoral neck BMD at the genome-wide level is intronic SNP rs17040773 located in the intronic region of the anaphase-promoting complex subunit 1 (ANAPC1) gene (p = 1.5 × 10-9). Here, we functionally evaluate the role of ANAPC1 in bone remodelling by examining the expression of ANAPC1 in human bone and muscle tissues and during the osteogenic differentiation of human primary mesenchymal stem cells (MSCs). The expression of ANAPC1 was significantly decreased 2.3-fold in bone tissues and 6.2-fold in muscle tissue from osteoporotic patients as compared to the osteoarthritic and control tissues. Next, we show that the expression of ANAPC1 changes during the osteogenic differentiation process of human MSCs. Moreover, the silencing of ANAPC1 in human osteosarcoma (HOS) cells reduced RUNX2 expression, suggesting that ANAPC1 affects osteogenic differentiation through RUNX2. Altogether, our results indicate that ANAPC1 plays a role in bone physiology and in the development of osteoporosis.
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Affiliation(s)
- Petra Malavašič
- General Hospital Novo Mesto, Šmihelska Cesta 1, 8000 Novo Mesto, Slovenia;
| | - Sara Polajžer
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta 7, 1000 Ljubljana, Slovenia
| | - Nika Lovšin
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta 7, 1000 Ljubljana, Slovenia
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3
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Lai HY, Yu YH, Jhou YT, Liao CW, Leu JY. Multiple intermolecular interactions facilitate rapid evolution of essential genes. Nat Ecol Evol 2023; 7:745-755. [PMID: 36997737 PMCID: PMC10172115 DOI: 10.1038/s41559-023-02029-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 02/21/2023] [Indexed: 04/01/2023]
Abstract
Essential genes are commonly assumed to function in basic cellular processes and to change slowly. However, it remains unclear whether all essential genes are similarly conserved or if their evolutionary rates can be accelerated by specific factors. To address these questions, we replaced 86 essential genes of Saccharomyces cerevisiae with orthologues from four other species that diverged from S. cerevisiae about 50, 100, 270 and 420 Myr ago. We identify a group of fast-evolving genes that often encode subunits of large protein complexes, including anaphase-promoting complex/cyclosome (APC/C). Incompatibility of fast-evolving genes is rescued by simultaneously replacing interacting components, suggesting it is caused by protein co-evolution. Detailed investigation of APC/C further revealed that co-evolution involves not only primary interacting proteins but also secondary ones, suggesting the evolutionary impact of epistasis. Multiple intermolecular interactions in protein complexes may provide a microenvironment facilitating rapid evolution of their subunits.
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Affiliation(s)
- Huei-Yi Lai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yen-Hsin Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Ting Jhou
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Chia-Wei Liao
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Jun-Yi Leu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
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Jaiswal N, Nandi D, Cheema PS, Nag A. The anaphase-promoting complex/cyclosome co-activator, Cdh1, is a novel target of human papillomavirus 16 E7 oncoprotein in cervical oncogenesis. Carcinogenesis 2022; 43:988-1001. [PMID: 35738876 DOI: 10.1093/carcin/bgac057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 06/01/2022] [Accepted: 06/23/2022] [Indexed: 01/13/2023] Open
Abstract
The transforming properties of the high-risk human papillomavirus (HPV) E7 oncoprotein are indispensable for driving the virus life cycle and pathogenesis. Besides inactivation of the retinoblastoma family of tumor suppressors as part of its oncogenic endeavors, E7-mediated perturbations of eminent cell cycle regulators, checkpoint proteins and proto-oncogenes are considered to be the tricks of its transformative traits. However, many such critical interactions are still unknown. In the present study, we have identified the anaphase-promoting complex/cyclosome (APC) co-activator, Cdh1, as a novel interacting partner and a degradation target of E7. We found that HPV16 E7-induced inactivation of Cdh1 promoted abnormal accumulation of multiple Cdh1 substrates. Such a mode of deregulation possibly contributes to HPV-mediated cervical oncogenesis. Our mapping studies recognized the C-terminal zinc-finger motif of E7 to associate with Cdh1 and interfere with the timely degradation of FoxM1, a bona fide Cdh1 substrate and a potent oncogene. Importantly, the E7 mutant with impaired interaction with Cdh1 exhibited defects in its ability for overriding typical cell cycle transition and oncogenic transformation, thereby validating the functional and pathological significance of the E7-Cdh1 axis during cervical carcinoma progression. Altogether, the findings from our study discover a unique nexus between E7 and APC/C-Cdh1, thereby adding to our understanding of the mechanism of E7-induced carcinogenesis and provide a promising target for the management of cervical carcinoma.
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Affiliation(s)
- Neha Jaiswal
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Marg, New Delhi, India
| | - Deeptashree Nandi
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Marg, New Delhi, India
| | - Pradeep Singh Cheema
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Marg, New Delhi, India
| | - Alo Nag
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Marg, New Delhi, India
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de Oliveira PN, da Silva LFC, Eloy NB. The role of APC/C in cell cycle dynamics, growth and development in cereal crops. FRONTIERS IN PLANT SCIENCE 2022; 13:987919. [PMID: 36247602 PMCID: PMC9558237 DOI: 10.3389/fpls.2022.987919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
Cereal crops can be considered the basis of human civilization. Thus, it is not surprising that these crops are grown in larger quantities worldwide than any other food supply and provide more energy to humankind than any other provision. Additionally, attempts to harness biomass consumption continue to increase to meet human energy needs. The high pressures for energy will determine the demand for crop plants as resources for biofuel, heat, and electricity. Thus, the search for plant traits associated with genetic increases in yield is mandatory. In multicellular organisms, including plants, growth and development are driven by cell division. These processes require a sequence of intricated events that are carried out by various protein complexes and molecules that act punctually throughout the cycle. Temporal controlled degradation of key cell division proteins ensures a correct onset of the different cell cycle phases and exit from the cell division program. Considering the cell cycle, the Anaphase-Promoting Complex/Cyclosome (APC/C) is an important conserved multi-subunit ubiquitin ligase, marking targets for degradation by the 26S proteasome. Studies on plant APC/C subunits and activators, mainly in the model plant Arabidopsis, revealed that they play a pivotal role in several developmental processes during growth. However, little is known about the role of APC/C in cereal crops. Here, we discuss the current understanding of the APC/C controlling cereal crop development.
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Abstract
Cytomegaloviruses (CMVs) are among the largest pathogenic viruses in mammals. To enable replication of their long double-stranded DNA genomes, CMVs induce profound changes in cell cycle regulation. A hallmark of CMV cell cycle control is the establishment of an unusual cell cycle arrest at the G1/S transition, which is characterized by the coexistence of cell cycle stimulatory and inhibitory activities. While CMVs interfere with cellular DNA synthesis and cell division, they activate S-phase-specific gene expression and nucleotide metabolism. This is facilitated by a set of CMV gene products that target master regulators of G1/S progression such as cyclin E and A kinases, Rb-E2F transcription factors, p53-p21 checkpoint proteins, the APC/C ubiquitin ligase, and the nucleotide hydrolase SAMHD1. While the major themes of cell cycle regulation are well conserved between human and murine CMVs (HCMV and MCMV), there are considerable differences at the level of viral cell cycle effectors and their mechanisms of action. Furthermore, both viruses have evolved unique mechanisms to sense the host cell cycle state and modulate the infection program accordingly. This review provides an overview of conserved and divergent features of G1/S control by MCMV and HCMV.
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7
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Human Immunodeficiency Virus Type 1 Vpr Mediates Degradation of APC1, a Scaffolding Component of the Anaphase-Promoting Complex/Cyclosome. J Virol 2021; 95:e0097120. [PMID: 34011540 DOI: 10.1128/jvi.00971-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
HIV-1 encodes several accessory proteins-Nef, Vif, Vpr, and Vpu-whose functions are to modulate the cellular environment to favor immune evasion and viral replication. While Vpr was shown to mediate a G2/M cell cycle arrest and provide a replicative advantage during infection of myeloid cells, the mechanisms underlying these functions remain unclear. In this study, we defined HIV-1 Vpr proximity interaction network using the BioID proximity labeling approach and identified 352 potential Vpr partners/targets, including several complexes, such as the cell cycle-regulatory anaphase-promoting complex/cyclosome (APC/C). Herein, we demonstrate that both the wild type and cell cycle-defective mutants of Vpr induce the degradation of APC1, an essential APC/C scaffolding protein, and show that this activity relies on the recruitment of DCAF1 by Vpr and the presence of a functional proteasome. Vpr forms a complex with APC1, and the APC/C coactivators Cdh1 and Cdc20 are associated with these complexes. Interestingly, we found that Vpr encoded by the prototypic HIV-1 NL4.3 does not interact efficiently with APC1 and is unable to mediate its degradation as a result of a N28S-G41N amino acid substitution. In contrast, we show that APC1 degradation is a conserved feature of several primary Vpr variants from transmitted/founder virus. Functionally, Vpr-mediated APC1 degradation did not impact the ability of the protein to induce a G2 cell cycle arrest during infection of CD4+ T cells or enhance HIV-1 replication in macrophages, suggesting that this conserved activity may be important for other aspects of HIV-1 pathogenesis. IMPORTANCE The function of the Vpr accessory protein during HIV-1 infection remains poorly defined. Several cellular targets of Vpr were previously identified, but their individual degradation does not fully explain the ability of Vpr to impair the cell cycle or promote HIV-1 replication in macrophages. Here, we used the unbiased proximity labeling approach, called BioID, to further define the Vpr proximity interaction network and identified several potentially new Vpr partners/targets. We validated our approach by focusing on a cell cycle master regulator, the APC/C complex, and demonstrated that Vpr mediated the degradation of a critical scaffolding component of APC/C called APC1. Furthermore, we showed that targeting of APC/C by Vpr did not impact the known activity of Vpr. Since degradation of APC1 is a conserved feature of several primary variants of Vpr, it is likely that the interplay between Vpr and APC/C governs other aspects of HIV-1 pathogenesis.
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Saleme MDLS, Andrade IR, Eloy NB. The Role of Anaphase-Promoting Complex/Cyclosome (APC/C) in Plant Reproduction. FRONTIERS IN PLANT SCIENCE 2021; 12:642934. [PMID: 33719322 PMCID: PMC7943633 DOI: 10.3389/fpls.2021.642934] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/03/2021] [Indexed: 05/06/2023]
Abstract
Most eukaryotic species propagate through sexual reproduction that requires male and female gametes. In flowering plants, it starts through a single round of DNA replication (S phase) and two consecutive chromosome segregation (meiosis I and II). Subsequently, haploid mitotic divisions occur, which results in a male gametophyte (pollen grain) and a female gametophyte (embryo sac) formation. In order to obtain viable gametophytes, accurate chromosome segregation is crucial to ensure ploidy stability. A precise gametogenesis progression is tightly regulated in plants and is controlled by multiple mechanisms to guarantee a correct evolution through meiotic cell division and sexual differentiation. In the past years, research in the field has shown an important role of the conserved E3-ubiquitin ligase complex, Anaphase-Promoting Complex/Cyclosome (APC/C), in this process. The APC/C is a multi-subunit complex that targets proteins for degradation via proteasome 26S. The functional characterization of APC/C subunits in Arabidopsis, which is one of the main E3 ubiquitin ligase that controls cell cycle, has revealed that all subunits investigated so far are essential for gametophytic development and/or embryogenesis.
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9
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VanGenderen C, Harkness TAA, Arnason TG. The role of Anaphase Promoting Complex activation, inhibition and substrates in cancer development and progression. Aging (Albany NY) 2020; 12:15818-15855. [PMID: 32805721 PMCID: PMC7467358 DOI: 10.18632/aging.103792] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/14/2020] [Indexed: 02/07/2023]
Abstract
The Anaphase Promoting Complex (APC), a multi-subunit ubiquitin ligase, facilitates mitotic and G1 progression, and is now recognized to play a role in maintaining genomic stability. Many APC substrates have been observed overexpressed in multiple cancer types, such as CDC20, the Aurora A and B kinases, and Forkhead box M1 (FOXM1), suggesting APC activity is important for cell health. We performed BioGRID analyses of the APC coactivators CDC20 and CDH1, which revealed that at least 69 proteins serve as APC substrates, with 60 of them identified as playing a role in tumor promotion and 9 involved in tumor suppression. While these substrates and their association with malignancies have been studied in isolation, the possibility exists that generalized APC dysfunction could result in the inappropriate stabilization of multiple APC targets, thereby changing tumor behavior and treatment responsiveness. It is also possible that the APC itself plays a crucial role in tumorigenesis through its regulation of mitotic progression. In this review the connections between APC activity and dysregulation will be discussed with regards to cell cycle dysfunction and chromosome instability in cancer, along with the individual roles that the accumulation of various APC substrates may play in cancer progression.
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Affiliation(s)
- Cordell VanGenderen
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Troy Anthony Alan Harkness
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Terra Gayle Arnason
- Department of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.,Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
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Mizrak A, Morgan DO. Polyanions provide selective control of APC/C interactions with the activator subunit. Nat Commun 2019; 10:5807. [PMID: 31862931 PMCID: PMC6925294 DOI: 10.1038/s41467-019-13864-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 12/04/2019] [Indexed: 01/18/2023] Open
Abstract
Transient interactions between the anaphase-promoting complex/cyclosome (APC/C) and its activator subunit Cdc20 or Cdh1 generate oscillations in ubiquitylation activity necessary to maintain the order of cell cycle events. Activator binds the APC/C with high affinity and exhibits negligible dissociation kinetics in vitro, and it is not clear how the rapid turnover of APC/C-activator complexes is achieved in vivo. Here, we describe a mechanism that controls APC/C-activator interactions based on the availability of substrates. We find that APC/C-activator dissociation is stimulated by abundant cellular polyanions such as nucleic acids and polyphosphate. Polyanions also interfere with substrate ubiquitylation. However, engagement with high-affinity substrate blocks the inhibitory effects of polyanions on activator binding and APC/C activity. We propose that this mechanism amplifies the effects of substrate affinity on APC/C function, stimulating processive ubiquitylation of high-affinity substrates and suppressing ubiquitylation of low-affinity substrates.
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Affiliation(s)
- Arda Mizrak
- Department of Physiology, University of California, San Francisco, CA, 94143, USA
| | - David O Morgan
- Department of Physiology, University of California, San Francisco, CA, 94143, USA.
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11
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Melloy PG. The anaphase-promoting complex: A key mitotic regulator associated with somatic mutations occurring in cancer. Genes Chromosomes Cancer 2019; 59:189-202. [PMID: 31652364 DOI: 10.1002/gcc.22820] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 12/14/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that helps control chromosome separation and exit from mitosis in many different kinds of organisms, including yeast, flies, worms, and humans. This review represents a new perspective on the connection between APC/C subunit mutations and cancer. The complex nature of APC/C and limited mutation analysis of its subunits has made it difficult to determine the relationship of each subunit to cancer. In this work, cancer genomic data were examined to identify APC/C subunits with a greater than 5% alteration frequency in 11 representative cancers using the cBioPortal database. Using the Genetic Determinants of Cancer Patient Survival database, APC/C subunits were also studied and found to be significantly associated with poor patient prognosis in several cases. In comparing these two kinds of cancer genomics data to published large-scale genomic analyses looking for cancer driver genes, ANAPC1 and ANAPC3/CDC27 stood out as being represented in all three types of analyses. Seven other subunits were found to be associated both with >5% alteration frequency in certain cancers and being associated with an effect on cancer patient prognosis. The aim of this review is to provide new approaches for investigators conducting in vivo studies of APC/C subunits and cancer progression. In turn, a better understanding of these APC/C subunits and their role in different cancers will help scientists design drugs that are more precisely targeted to certain cancers, using APC/C mutation status as a biomarker.
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Affiliation(s)
- Patricia G Melloy
- Department of Biological and Allied Health Sciences, Fairleigh Dickinson University, Madison, New Jersey
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12
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Mutations in ANAPC1, Encoding a Scaffold Subunit of the Anaphase-Promoting Complex, Cause Rothmund-Thomson Syndrome Type 1. Am J Hum Genet 2019; 105:625-630. [PMID: 31303264 DOI: 10.1016/j.ajhg.2019.06.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 06/11/2019] [Indexed: 11/21/2022] Open
Abstract
Rothmund-Thomson syndrome (RTS) is an autosomal-recessive disorder characterized by poikiloderma, sparse hair, short stature, and skeletal anomalies. Type 2 RTS, which is defined by the presence of bi-allelic mutations in RECQL4, is characterized by increased cancer susceptibility and skeletal anomalies, whereas the genetic basis of RTS type 1, which is associated with juvenile cataracts, is unknown. We studied ten individuals, from seven families, who had RTS type 1 and identified a deep intronic splicing mutation of the ANAPC1 gene, a component of the anaphase-promoting complex/cyclosome (APC/C), in all affected individuals, either in the homozygous state or in trans with another mutation. Fibroblast studies showed that the intronic mutation causes the activation of a 95 bp pseudoexon, leading to mRNAs with premature termination codons and nonsense-mediated decay, decreased ANAPC1 protein levels, and prolongation of interphase. Interestingly, mice that were heterozygous for a knockout mutation have an increased incidence of cataracts. Our results demonstrate that deficiency in the APC/C is a cause of RTS type 1 and suggest a possible link between the APC/C and RECQL4 helicase because both proteins are involved in DNA repair and replication.
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13
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Curtis NL, Bolanos-Garcia VM. The Anaphase Promoting Complex/Cyclosome (APC/C): A Versatile E3 Ubiquitin Ligase. Subcell Biochem 2019; 93:539-623. [PMID: 31939164 DOI: 10.1007/978-3-030-28151-9_18] [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: 03/25/2023]
Abstract
In the present chapter we discuss the essential roles of the human E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) in mitosis as well as the emerging evidence of important APC/C roles in cellular processes beyond cell division control such as regulation of genomic integrity and cell differentiation of the nervous system. We consider the potential incipient role of APC/C dysregulation in the pathophysiology of the neurological disorder Alzheimer's disease (AD). We also discuss how certain Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) viruses take control of the host's cell division regulatory system through harnessing APC/C ubiquitin ligase activity and hypothesise the plausible molecular mechanisms underpinning virus manipulation of the APC/C. We also examine how defects in the function of this multisubunit protein assembly drive abnormal cell proliferation and lastly argue the potential of APC/C as a promising therapeutic target for the development of innovative therapies for the treatment of chronic malignancies such as cancer.
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Affiliation(s)
- Natalie L Curtis
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, England, UK
| | - Victor M Bolanos-Garcia
- Faculty of Health and Life Sciences, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, England, UK.
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14
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Watson ER, Brown NG, Peters JM, Stark H, Schulman BA. Posing the APC/C E3 Ubiquitin Ligase to Orchestrate Cell Division. Trends Cell Biol 2018; 29:117-134. [PMID: 30482618 DOI: 10.1016/j.tcb.2018.09.007] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/23/2018] [Accepted: 09/25/2018] [Indexed: 01/01/2023]
Abstract
The anaphase promoting complex/cyclosome (APC/C) E3 ligase controls mitosis and nonmitotic pathways through interactions with proteins that coordinate ubiquitylation. Since the discovery that the catalytic subunits of APC/C are conformationally dynamic cullin and RING proteins, many unexpected and intricate regulatory mechanisms have emerged. Here, we review structural knowledge of this regulation, focusing on: (i) coactivators, E2 ubiquitin (Ub)-conjugating enzymes, and inhibitors engage or influence multiple sites on APC/C including the cullin-RING catalytic core; and (ii) the outcomes of these interactions rely on mobility of coactivators and cullin-RING domains, which permits distinct conformations specifying different functions. Thus, APC/C is not simply an interaction hub, but is instead a dynamic, multifunctional molecular machine whose structure is remodeled by binding partners to achieve temporal ubiquitylation regulating cell division.
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Affiliation(s)
- Edmond R Watson
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, 82152, Germany
| | - Nicholas G Brown
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Campus Vienna Biocenter (VBC) 1, 1030 Vienna, Austria
| | - Holger Stark
- Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Brenda A Schulman
- Department of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, Martinsried, 82152, Germany; Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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15
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APC/C FZR-1 Controls SAS-5 Levels To Regulate Centrosome Duplication in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2017; 7:3937-3946. [PMID: 29030390 PMCID: PMC5714490 DOI: 10.1534/g3.117.300260] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
As the primary microtubule-organizing center, centrosomes play a key role in establishing mitotic bipolar spindles that secure correct transmission of genomic content. For the fidelity of cell division, centrosome number must be strictly controlled by duplicating only once per cell cycle. Proper levels of centrosome proteins are shown to be critical for normal centrosome number and function. Overexpressing core centrosome factors leads to extra centrosomes, while depleting these factors results in centrosome duplication failure. In this regard, protein turnover by the ubiquitin-proteasome system provides a vital mechanism for the regulation of centrosome protein levels. Here, we report that FZR-1, the Caenorhabditis elegans homolog of Cdh1/Hct1/Fzr, a coactivator of the anaphase promoting complex/cyclosome (APC/C), an E3 ubiquitin ligase, functions as a negative regulator of centrosome duplication in the C. elegans embryo. During mitotic cell division in the early embryo, FZR-1 is associated with centrosomes and enriched at nuclei. Loss of fzr-1 function restores centrosome duplication and embryonic viability to the hypomorphic zyg-1(it25) mutant, in part, through elevated levels of SAS-5 at centrosomes. Our data suggest that the APC/CFZR-1 regulates SAS-5 levels by directly recognizing the conserved KEN-box motif, contributing to proper centrosome duplication. Together, our work shows that FZR-1 plays a conserved role in regulating centrosome duplication in C. elegans.
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Alfieri C, Zhang S, Barford D. Visualizing the complex functions and mechanisms of the anaphase promoting complex/cyclosome (APC/C). Open Biol 2017; 7:170204. [PMID: 29167309 PMCID: PMC5717348 DOI: 10.1098/rsob.170204] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/10/2017] [Indexed: 12/17/2022] Open
Abstract
The anaphase promoting complex or cyclosome (APC/C) is a large multi-subunit E3 ubiquitin ligase that orchestrates cell cycle progression by mediating the degradation of important cell cycle regulators. During the two decades since its discovery, much has been learnt concerning its role in recognizing and ubiquitinating specific proteins in a cell-cycle-dependent manner, the mechanisms governing substrate specificity, the catalytic process of assembling polyubiquitin chains on its target proteins, and its regulation by phosphorylation and the spindle assembly checkpoint. The past few years have witnessed significant progress in understanding the quantitative mechanisms underlying these varied APC/C functions. This review integrates the overall functions and properties of the APC/C with mechanistic insights gained from recent cryo-electron microscopy (cryo-EM) studies of reconstituted human APC/C complexes.
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Affiliation(s)
- Claudio Alfieri
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Suyang Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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17
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Chi J, Zheng X, Gao M, Zhao J, Li D, Li J, Dong L, Ruan X. Integrated microRNA-mRNA analyses of distinct expression profiles in follicular thyroid tumors. Oncol Lett 2017; 14:7153-7160. [PMID: 29344146 PMCID: PMC5754833 DOI: 10.3892/ol.2017.7146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 08/10/2017] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRNAs/miRs) are small non-coding RNAs identified in plants, animals and certain viruses; they function in RNA silencing and post-transcriptional regulation of gene expression. miRNAs also serve an important role in the pathogenesis, diagnosis and treatment of tumors. However, few studies have investigated the role of miRNAs in thyroid tumors. In the present study, the expression of miRNA and mRNA was compared between follicular thyroid carcinoma (FTC) and follicular thyroid adenoma (FA) samples, and then miRNA-mRNA regulatory network analysis was performed. Microarray datasets (GSE29315 and GSE62054) were downloaded from the Gene Expression Omnibus, and profiling data were processed with R software. Differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) were determined, and Gene Ontology enrichment analysis was subsequently performed for DEGs using the Database for Annotation, Visualization and Integrated Discovery. The target genes of the DEMs were identified with miRWalk, miRecords and TarMir databases. Network analysis of the DEMs and DEMs-targeted DEGs was performed using Cytoscape software. In GSE62054, 23 downregulated and 9 upregulated miRNAs were identified. In GSE29315, 42 downregulated and 44 upregulated mRNAs were identified. A total of 36 miRNA-gene pairs were also identified. Network analysis indicated a co-regulatory association between miR-296-5p, miR-10a, miR-139-5p, miR-452, miR-493, miR-7, miR-137, miR-144, miR-145 and corresponding targeted mRNAs, including TNF receptor superfamily member 11b, benzodiazepine receptor (peripheral) -associated protein 1, and transforming growth factor β receptor 2. These results suggest that miRNA-mRNAs networks serve an important role in the pathogenesis, diagnosis and treatment of FTC and FA.
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Affiliation(s)
- Jiadong Chi
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China.,Department of Graduate College, Tianjin Medical University, Tianjin 300070, P.R. China
| | - Xiangqian Zheng
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China
| | - Ming Gao
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China
| | - Jingzhu Zhao
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China
| | - Dapeng Li
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China
| | - Jiansen Li
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China
| | - Li Dong
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China
| | - Xianhui Ruan
- Department of Thyroid and Neck Tumors, Tianjin Medical University Cancer Institute and Hospital, Oncology Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center of Cancer, Tianjin 300060, P.R. China
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18
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Rahimi H, Shokrgozar MA, Madadkar-Sobhani A, Mahdian R, Foroumadi A, Karimipoor M. Structural Insight into Anaphase Promoting Complex 3 Structure and Docking with a Natural Inhibitory Compound. Adv Biomed Res 2017; 6:26. [PMID: 28401073 PMCID: PMC5359995 DOI: 10.4103/2277-9175.201683] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Anaphase promoting complex (APC) is the biggest Cullin-RING E3 ligase and is very important in cell cycle control; many anti-cancer agents target this. APC controls the onset of chromosome separation and mitotic exit through securin and cyclin B degradation, respectively. Its APC3 subunit identifies the APC activators-Cdh1 and Cdc20. MATERIALS AND METHODS The structural model of the APC3 subunit of APC was developed by means of computational techniques; the binding of a natural inhibitory compound to APC3 was also investigated. RESULTS It was found that APC3 structure consists of numerous helices organized in anti-parallel and the overall model is superhelical of tetratrico-peptide repeat (TPR) domains. Furthermore, binding pocket of the natural inhibitory compound as APC3 inhibitor was shown. CONCLUSION The findings are beneficial to understand the mechanism of the APC activation and design inhibitory compounds.
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Affiliation(s)
- Hamzeh Rahimi
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | | | - Armin Madadkar-Sobhani
- Department of Life Sciences, Barcelona Supercomputing Center, Barcelona, Spain; Department of Bioinformatics, Institute of Biophysics and Biochemistry, University of Tehran, Tehran, Iran
| | - Reza Mahdian
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Alireza Foroumadi
- Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Morteza Karimipoor
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
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19
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Cdc20: At the Crossroads between Chromosome Segregation and Mitotic Exit. Trends Biochem Sci 2017; 42:193-205. [PMID: 28202332 DOI: 10.1016/j.tibs.2016.12.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/13/2016] [Accepted: 12/06/2016] [Indexed: 11/21/2022]
Abstract
Cell-division cycle protein 20 homologue (Cdc20) has important functions in chromosome segregation and mitotic exit. Cdc20 is the target of the spindle assembly checkpoint (SAC) and a key cofactor of the anaphase-promoting complex or cyclosome (APC/C) E3 ubiquitin ligase, thus regulating APC/C ubiquitin activity on specific substrates for their subsequent degradation by the proteasome. Here we discuss the roles of Cdc20 in SAC signalling and mitotic exit, describe how the integration of traditional approaches with emerging technologies has revealed new details of Cdc20 functions, comment about the potential of Cdc20 as a therapeutic target for the treatment of human malignancies, and discuss recent advances and controversies in the mechanistic understanding of the control of chromosome segregation during cell division.
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20
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Corbett KD. Molecular Mechanisms of Spindle Assembly Checkpoint Activation and Silencing. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2017; 56:429-455. [PMID: 28840248 DOI: 10.1007/978-3-319-58592-5_18] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In eukaryotic cell division, the Spindle Assembly Checkpoint (SAC) plays a key regulatory role by monitoring the status of chromosome-microtubule attachments and allowing chromosome segregation only after all chromosomes are properly attached to spindle microtubules. While the identities of SAC components have been known, in some cases, for over two decades, the molecular mechanisms of the SAC have remained mostly mysterious until very recently. In the past few years, advances in biochemical reconstitution, structural biology, and bioinformatics have fueled an explosion in the molecular understanding of the SAC. This chapter seeks to synthesize these recent advances and place them in a biological context, in order to explain the mechanisms of SAC activation and silencing at a molecular level.
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Affiliation(s)
- Kevin D Corbett
- Ludwig Institute for Cancer Research, San Diego Branch, La Jolla, CA, USA.
- Departments of Cellular & Molecular Medicine and Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, 92093, USA.
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21
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Velma V, Dasari SR, Tchounwou PB. Low Doses of Cisplatin Induce Gene Alterations, Cell Cycle Arrest, and Apoptosis in Human Promyelocytic Leukemia Cells. Biomark Insights 2016; 11:113-21. [PMID: 27594783 PMCID: PMC4998075 DOI: 10.4137/bmi.s39445] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 04/17/2016] [Accepted: 04/26/2016] [Indexed: 12/20/2022] Open
Abstract
Cisplatin is a known antitumor drug, but its mechanisms of action are not fully elucidated. In this research, we studied the anticancer potential of cisplatin at doses of 1, 2, or 3 µM using HL-60 cells as a test model. We investigated cisplatin effects at the molecular level using RNA sequencing, cell cycle analysis, and apoptotic assay after 24, 48, 72, and 96 hours of treatment. The results show that many genes responsible for molecular and cellular functions were significantly altered. Cisplatin treatment also caused the cells to be arrested at the DNA synthesis phase, and as the time increases, the cells gradually accumulated at the sub-G1 phase. Also, as the dose increases, a significant number of cells entered into the apoptotic and necrotic stages. Altogether, the data show that low doses of cisplatin significantly impact the viability of HL-60 cells, through modulation of gene expression, cell cycle, and apoptosis.
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Affiliation(s)
- Venkatramreddy Velma
- Cellomics and Toxicogenomics Research Laboratory, NIH/NIMHD RCMI-Center for Environmental Health, College of Science, Engineering and Technology, Jackson State University, Jackson, MS, USA
| | - Shaloam R Dasari
- Cellomics and Toxicogenomics Research Laboratory, NIH/NIMHD RCMI-Center for Environmental Health, College of Science, Engineering and Technology, Jackson State University, Jackson, MS, USA
| | - Paul B Tchounwou
- Cellomics and Toxicogenomics Research Laboratory, NIH/NIMHD RCMI-Center for Environmental Health, College of Science, Engineering and Technology, Jackson State University, Jackson, MS, USA
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22
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Abstract
The spindle assembly checkpoint is a safeguard mechanism that coordinates cell-cycle progression during mitosis with the state of chromosome attachment to the mitotic spindle. The checkpoint prevents mitotic cells from exiting mitosis in the presence of unattached or improperly attached chromosomes, thus avoiding whole-chromosome gains or losses and their detrimental effects on cell physiology. Here, I review a considerable body of recent progress in the elucidation of the molecular mechanisms underlying checkpoint signaling, and identify a number of unresolved questions.
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Affiliation(s)
- Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany; Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany.
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23
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Rahimi H, Ahmadzadeh A, Yousef-amoli S, Kokabee L, Shokrgozar MA, Mahdian R, Karimipoor M. The expression pattern of APC2 and APC7 in various cancer cell lines and AML patients. Adv Med Sci 2015; 60:259-63. [PMID: 26046517 DOI: 10.1016/j.advms.2015.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 03/11/2015] [Accepted: 04/30/2015] [Indexed: 01/29/2023]
Abstract
PURPOSE Anaphase promoting complex (APC/C) is an E3 ligase enzyme, which ubiquinates various proteins involved in the cell cycle. This protein complex may have a pivotal role in the cell cycle control affecting pathological conditions such as cancer. APC7 and APC2 subunits of the APC/C complex are involved in the substrate recognition and the catalytic reaction, respectively. MATERIALS AND METHODS In this study, quantitative Real-time PCR was used to analyse APC2 and APC7 expression in different cancer cell lines as well as AML patient's blood cells. RESULTS The results showed that APC2 and APC7 subunits were both over expressed in cancer cell lines (p=0.008). The mean expression ratio of APC2 and APC7 in different cancer cells were 2.60±0.22 and 4.83±0.11, respectively. An increase in expression of APC2 and APC7 was seen among 12 out of 14 AML patients (85%). There was a significant positive correlation between APC2 upregulation and the detection of splenomegaly in the patients (r=0.808, p=0.001). CONCLUSION This was the first study suggesting that APC/C upregulation may contribute to the pathogenesis of cancer and can be used as a molecular biomarker to predict the progression and the prognosis of AML.
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Affiliation(s)
- Hamzeh Rahimi
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Ahmad Ahmadzadeh
- Thalassemia and Hemoglobinopathy Research Center, Shafa Hospital, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shamseddin Yousef-amoli
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Leila Kokabee
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | | | - Reza Mahdian
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
| | - Mortaza Karimipoor
- Molecular Medicine Department, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran.
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24
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Zhang T, Qi ST, Huang L, Ma XS, Ouyang YC, Hou Y, Shen W, Schatten H, Sun QY. Cyclin B3 controls anaphase onset independent of spindle assembly checkpoint in meiotic oocytes. Cell Cycle 2015; 14:2648-54. [PMID: 26125114 DOI: 10.1080/15384101.2015.1064567] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cyclin B3 is a relatively new member of the cyclin family whose functions are little known. We found that depletion of cyclin B3 inhibited metaphase-anaphase transition as indicated by a well-sustained MI spindle and cyclin B1 expression in meiotic oocytes after extended culture. This effect was independent of spindle assembly checkpoint activity, since both Bub3 and BubR1 signals were not observed at kinetochores in MI-arrested cells. The metaphase I arrest was not rescued by either Mad2 knockdown or cdc20 overexpression, but it was rescued by securin RNAi. We conclude that cyclin B3 controls the metaphase-anaphase transition by activating APC/C(cdc20) in meiotic oocytes, a process that does not rely on SAC activity.
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Affiliation(s)
- Teng Zhang
- a Institute of Reproductive Sciences; College of Animal Science and Technology; Qingdao Agricultural University ; Qingdao , China
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25
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Chang L, Zhang Z, Yang J, McLaughlin SH, Barford D. Atomic structure of the APC/C and its mechanism of protein ubiquitination. Nature 2015; 522:450-454. [PMID: 26083744 PMCID: PMC4608048 DOI: 10.1038/nature14471] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/10/2015] [Indexed: 12/12/2022]
Abstract
The anaphase-promoting complex (APC/C) is a multimeric RING E3 ubiquitin ligase that controls chromosome segregation and mitotic exit. Its regulation by coactivator subunits, phosphorylation, the mitotic checkpoint complex and interphase early mitotic inhibitor 1 (Emi1) ensures the correct order and timing of distinct cell-cycle transitions. Here we use cryo-electron microscopy to determine atomic structures of APC/C-coactivator complexes with either Emi1 or a UbcH10-ubiquitin conjugate. These structures define the architecture of all APC/C subunits, the position of the catalytic module and explain how Emi1 mediates inhibition of the two E2s UbcH10 and Ube2S. Definition of Cdh1 interactions with the APC/C indicates how they are antagonized by Cdh1 phosphorylation. The structure of the APC/C with UbcH10-ubiquitin reveals insights into the initiating ubiquitination reaction. Our results provide a quantitative framework for the design of future experiments to investigate APC/C functions in vivo.
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MESH Headings
- Anaphase-Promoting Complex-Cyclosome/chemistry
- Anaphase-Promoting Complex-Cyclosome/metabolism
- Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Antigens, CD
- Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc1 Subunit, Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc10 Subunit, Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Apc11 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc11 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc3 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc3 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc8 Subunit, Anaphase-Promoting Complex-Cyclosome/chemistry
- Apc8 Subunit, Anaphase-Promoting Complex-Cyclosome/metabolism
- Apc8 Subunit, Anaphase-Promoting Complex-Cyclosome/ultrastructure
- Cadherins/chemistry
- Cadherins/metabolism
- Cadherins/ultrastructure
- Catalytic Domain
- Cell Cycle Proteins/chemistry
- Cell Cycle Proteins/metabolism
- Cell Cycle Proteins/ultrastructure
- Cryoelectron Microscopy
- Cytoskeletal Proteins/chemistry
- Cytoskeletal Proteins/metabolism
- F-Box Proteins/chemistry
- F-Box Proteins/metabolism
- F-Box Proteins/ultrastructure
- Humans
- Lysine/metabolism
- Models, Molecular
- Phosphorylation
- Protein Binding
- Protein Subunits/chemistry
- Protein Subunits/metabolism
- Structure-Activity Relationship
- Substrate Specificity
- Ubiquitin/chemistry
- Ubiquitin/metabolism
- Ubiquitin/ultrastructure
- Ubiquitin-Conjugating Enzymes/chemistry
- Ubiquitin-Conjugating Enzymes/metabolism
- Ubiquitin-Conjugating Enzymes/ultrastructure
- Ubiquitination
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Affiliation(s)
- Leifu Chang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Stephen H McLaughlin
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
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26
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Ren YQ, Fu F, Han J. MiR-27a modulates radiosensitivity of triple-negative breast cancer (TNBC) cells by targeting CDC27. Med Sci Monit 2015; 21:1297-303. [PMID: 25943633 PMCID: PMC4548742 DOI: 10.12659/msm.893974] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background MiR-27a is significantly overexpressed in triple-negative breast cancer (TNBC). However, the exact biological function of MiR-27a in TNBC is not fully understood. In this study, we verified miR-27a expression in TNBC cells and explored how its overexpression modulates radiosensitivity of the cells. Material/Method qRT-PCR analysis was performed to study miR-27a expression in TNBC lines MDA-MB-435 and MDA-MB-231 and in normal human breast epithelial cell line MCF10A. Dual luciferase assay was performed to verify a putative downstream target of miR-27a, CDC27. CCK-8 assay was used to assess the influence of miR-27a-CDC27 axis on cell proliferation under irradiation (IR) treatment. Results We confirmed significantly higher miR-27a expression in 2 TNBC cell lines – MDA-MB-435 and MDA-MB-231 – than in human breast epithelial cell line MCF10A. miR-27a could modulate proliferation and radiosensitivity of TNBC cells. CDC-27 is a direct target of miR-27a and its downregulation conferred increased radioresistance of the cells. Conclusions The miR-27a-CDC27 axis might play an important role in modulating response to radiotherapy in TNBC cells. Testing miR-27a expression might be a useful way to identify a subgroup of patients who will benefit from an IR-based therapeutic approach.
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Affiliation(s)
- Yong-qiang Ren
- Clinical Laboratory, The Central Hospital of Yishui, Linyi, Shandong, China (mainland)
| | - Fengkui Fu
- Dpartment of Radiology, People's Hospital of Binzhou, Binzhou, Shandong, China (mainland)
| | - Jianjun Han
- Department of Breast Surgery, Affiliated Hospital of Hebei University of Engineering, Handan, Hebei, China (mainland)
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27
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Studies on the Contribution of Human Cytomegalovirus UL21a and UL97 to Viral Growth and Inactivation of the Anaphase-Promoting Complex/Cyclosome (APC/C) E3 Ubiquitin Ligase Reveal a Unique Cellular Mechanism for Downmodulation of the APC/C Subunits APC1, APC4, and APC5. J Virol 2015; 89:6928-39. [PMID: 25903336 DOI: 10.1128/jvi.00403-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 04/17/2015] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Human cytomegalovirus (HCMV) deregulates the cell cycle by several means, including inactivation of the anaphase-promoting complex/cyclosome (APC/C) E3 ubiquitin ligase. Viral proteins UL97 and UL21a, respectively, affect the APC/C by phosphorylation of APC/C coactivator Cdh1 and by inducing the degradation of subunits APC4 and APC5, which along with APC1 form the APC/C platform subcomplex. The aim of this study was to further characterize the mechanism of APC/C inactivation and define the relative contributions of UL21a and UL97 to APC/C substrate accumulation and to viral growth. We show that in uninfected cells, UL21a but not UL97 can disrupt APC/C function, leading to the accumulation of substrates. We find that UL21a is necessary and sufficient to induce the degradation of APC1, in addition to the previously reported APC4 and APC5. We also demonstrate that there is a previously unreported cellular mechanism for a specific decrease in the levels of all three platform subunits, APC1, APC4, and APC5, upon the depletion of any one of these subunits or of subunit APC8. Finally, we show that at a low multiplicity of infection, either UL97 or UL21a can partially complement a growth-defective mutant virus lacking both UL21a and UL97, with significantly greater benefit afforded by the expression of both proteins. This double mutant also can be partially rescued by inactivation of the APC/C using small interfering RNAs against specific subunits. These results further our understanding of HCMV's interaction with the cell cycle machinery and reveal a new cellular pattern of APC/C subunit downmodulation. IMPORTANCE HCMV lytic infection subverts the host cell cycle machinery in multiple ways. A major effect is inactivation of the APC/C, which plays a central role in the control of cell cycle progression. This study provides further insight into the mechanism of inactivation. We discovered that the APC1 subunit, which along with APC4 and APC5 form the platform subcomplex of the APC/C, is an additional target of the degradation induced by HCMV protein UL21a. This study also shows for the first time that there is a unique cellular process in uninfected cells whereby depletion of APC1, APC4, APC5, or APC8 recapitulates the pattern of HCMV-mediated APC/C subunit degradation.
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28
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Barford D. Understanding the structural basis for controlling chromosome division. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2015; 373:20130392. [PMID: 25624511 PMCID: PMC4308986 DOI: 10.1098/rsta.2013.0392] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The process of chromosome division, termed mitosis, involves a complex sequence of events that is tightly controlled to ensure that the faithful segregation of duplicated chromosomes is coordinated with each cell division cycle. The large macromolecular complex responsible for regulating this process is the anaphase-promoting complex or cyclosome (APC/C). In humans, the APC/C is assembled from 20 subunits derived from 15 different proteins. The APC/C functions to ubiquitinate cell cycle regulatory proteins, thereby targeting them for destruction by the proteasome. This review describes our research aimed at understanding the structure and mechanism of the APC/C. We have determined the crystal structures of individual subunits and subcomplexes that provide atomic models to interpret density maps of the whole complex derived from single particle cryo-electron microscopy. With this information, we are generating pseudo-atomic models of functional states of the APC/C that provide insights into its overall architecture and mechanisms of substrate recognition, catalysis and regulation by inhibitory complexes.
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Affiliation(s)
- David Barford
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
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Roccuzzo M, Visintin C, Tili F, Visintin R. FEAR-mediated activation of Cdc14 is the limiting step for spindle elongation and anaphase progression. Nat Cell Biol 2015; 17:251-61. [PMID: 25706236 DOI: 10.1038/ncb3105] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 01/09/2015] [Indexed: 01/01/2023]
Abstract
Cleavage of cohesins and cyclin-dependent kinase (CDK) inhibition are thought to be sufficient for triggering chromosome segregation. Here we identify an essential requirement for anaphase chromosome movement. We show that, at anaphase onset, the phosphatase Cdc14 and the polo-like kinase Cdc5 are redundantly required to drive spindle elongation. This role of Cdc14 is mediated by the FEAR network, a group of proteins that activates Cdc14 at anaphase onset, and we suggest that Cdc5 facilitates both Cdc14 activation and CDK inhibition. We further identify the kinesin-5 motor protein Cin8 as a key target of Cdc14. Indeed, Cin8 mutants lacking critical CDK phosphorylation sites suppress the requirement for Cdc14 and Cdc5 in anaphase spindle elongation. Our results indicate that cohesin dissolution and CDK inhibition per se are not sufficient to drive sister chromatid segregation but that the motor protein Cin8 must be activated to elongate the spindle.
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Affiliation(s)
- Michela Roccuzzo
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
| | - Clara Visintin
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
| | - Federico Tili
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
| | - Rosella Visintin
- Department of Experimental Oncology, European Institute of Oncology, Milan 20139, Italy
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30
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Guo H, Chen W, Ming J, Zhong R, Yi P, Zhu B, Miao X, Huang T. Association between polymorphisms in cdc27 and breast cancer in a Chinese population. Tumour Biol 2015; 36:5299-304. [PMID: 25680405 DOI: 10.1007/s13277-015-3190-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 01/30/2015] [Indexed: 10/24/2022] Open
Abstract
Cdc27, as a core component of anaphase-promoting complex (APC), is a cell cycle regulator, which participates in control of mitotic checkpoint and surveys the mitotic spindle to maintain chromosomal integrity. It was hypothesized that polymorphisms in cdc27 gene might contribute to the susceptibility of breast cancer (BC) through influencing the mitotic progression of cells. Therefore, a hospital-based case-control study with 463 BC patients and 536 controls was implemented to investigate the association of six single-nucleotide polymorphisms (SNPs) in cdc27 and BC risk in a Chinese Han population. Among the six SNPs, two SNPs of rs11570443 and rs12601027 were positively correlated with BC risk. Individuals carrying rs11570443-CT or CC genotypes showed a higher BC risk with the OR of 1.75 (95 % confidence interval (CI) = 1.13-1.69), compared with those carrying rs11570443-TT genotype. For rs12601027, an increased BC risk was significantly associated with homozygote TT genotype (odds ratio (OR) = 1.49, 95 % CI = 1.12-1.98) compared with homozygote CC and heterozygote CT genotypes. In addition, a significant interaction effect of these two SNPs was found. The rs12601027-TT in combination with rs11570443-CT/CC genotypes showed a strongly elevated risk of BC compared with rs12601027-CC/CT and rs11570443-TT genotype (OR = 1.95, 95 % CI = 1.06-3.59). These findings suggested that polymorphisms in cdc27 may contribute to the susceptibility of BC though functional studies are needed to further elucidate the underling mechanisms of the associations.
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Affiliation(s)
- Hui Guo
- Department of Breast and Thyroid Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
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Rahimi H, Negahdari B, Shokrgozar M, Madadkar-Sobhani A, Mahdian R, Foroumadi A, Amin MK, Karimipoor M. A structural model of the anaphase promoting complex co-activator (Cdh1) and in silico design of inhibitory compounds. Res Pharm Sci 2015; 10:59-67. [PMID: 26430458 PMCID: PMC4578213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Anaphase promoting complex (APC) controls cell cycle and chromosome segregation. The APC activation occurs after binding of co-activators, cdh1 and cdc20. Cdh1 plays a role in cancer pathogenesis and is known as a potential drug target. The main aim of this study was prediction of 3D structure of cdh1 and designing the inhibitory compounds based on the structural model. First, 3D structure of cdh1 was predicted by means of homology modelling and molecular dynamics tools, MODELLER and Gromacs package, respectively. Then, inhibitory compounds were designed using virtual screening and molecular docking by means AutoDock package. The overall structure of cdh1 is propeller like and each DW40 repeat contains four anti-parallel beta-sheets. Moreover, binding pocket of the inhibitory compounds was determined. The results might be helpful in finding a suitable cdh1 inhibitor for the treatment of cancer.
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Affiliation(s)
- H. Rahimi
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, I.R. Iran
| | - B. Negahdari
- Department of Medical Biotechnology, Advanced Medical Science School, Tehran University of Medical Sciences, Tehran, I.R. Iran
| | - M.A. Shokrgozar
- National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, I.R. Iran
| | - A. Madadkar-Sobhani
- Life Sciences Department, Barcelona Supercomputing Center (BSC), Barcelona 08034, Spain,Department of Bioinformatics, Institute of Biophysics and Biochemistry (IBB), University of Tehran, Tehran, I.R. Iran
| | - R. Mahdian
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, I.R. Iran
| | - A. Foroumadi
- Faculty of Pharmacy and Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences, Tehran, I.R. Iran
| | - M. Kafshdouzi Amin
- Faculty of Paramedical Sciences, Qazvin University of Medical Sciences, Qazvin, I.R. Iran
| | - M. Karimipoor
- Department of Molecular Medicine, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, I.R. Iran,Corresponding author: M. Karimipoor Tel: 0098 9122806133, Fax: 00982166480780
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32
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Yamaguchi M, Yu S, Qiao R, Weissmann F, Miller DJ, VanderLinden R, Brown NG, Frye JJ, Peters JM, Schulman BA. Structure of an APC3-APC16 complex: insights into assembly of the anaphase-promoting complex/cyclosome. J Mol Biol 2014; 427:1748-64. [PMID: 25490258 DOI: 10.1016/j.jmb.2014.11.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 11/14/2014] [Accepted: 11/15/2014] [Indexed: 01/05/2023]
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a massive E3 ligase that controls mitosis by catalyzing ubiquitination of key cell cycle regulatory proteins. The APC/C assembly contains two subcomplexes: the "Platform" centers around a cullin-RING-like E3 ligase catalytic core; the "Arc Lamp" is a hub that mediates transient association with regulators and ubiquitination substrates. The Arc Lamp contains the small subunits APC16, CDC26, and APC13, and tetratricopeptide repeat (TPR) proteins (APC7, APC3, APC6, and APC8) that homodimerize and stack with quasi-2-fold symmetry. Within the APC/C complex, APC3 serves as center for regulation. APC3's TPR motifs recruit substrate-binding coactivators, CDC20 and CDH1, via their C-terminal conserved Ile-Arg (IR) tail sequences. Human APC3 also binds APC16 and APC7 and contains a >200-residue loop that is heavily phosphorylated during mitosis, although the basis for APC3 interactions and whether loop phosphorylation is required for ubiquitination are unclear. Here, we map the basis for human APC3 assembly with APC16 and APC7, report crystal structures of APC3Δloop alone and in complex with the C-terminal domain of APC16, and test roles of APC3's loop and IR tail binding surfaces in APC/C-catalyzed ubiquitination. The structures show how one APC16 binds asymmetrically to the symmetric APC3 dimer and, together with biochemistry and prior data, explain how APC16 recruits APC7 to APC3, show how APC3's C-terminal domain is rearranged in the full APC/C assembly, and visualize residues in the IR tail binding cleft important for coactivator-dependent ubiquitination. Overall, the results provide insights into assembly, regulation, and interactions of TPR proteins and the APC/C.
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Affiliation(s)
- Masaya Yamaguchi
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shanshan Yu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Renping Qiao
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Florian Weissmann
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Darcie J Miller
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Ryan VanderLinden
- Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105 USA
| | - Nicholas G Brown
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jeremiah J Frye
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jan-Michael Peters
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Brenda A Schulman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105 USA.
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Kelly A, Wickliffe KE, Song L, Fedrigo I, Rape M. Ubiquitin chain elongation requires E3-dependent tracking of the emerging conjugate. Mol Cell 2014; 56:232-245. [PMID: 25306918 DOI: 10.1016/j.molcel.2014.09.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 12/22/2022]
Abstract
Protein modification with ubiquitin chains is an essential signaling event catalyzed by E3 ubiquitin ligases. Most human E3s contain a signature RING domain that recruits a ubiquitin-charged E2 and a separate domain for substrate recognition. How RING-E3s can build polymeric ubiquitin chains while binding substrates and E2s at defined interfaces remains poorly understood. Here, we show that the RING-E3 APC/C catalyzes chain elongation by strongly increasing the affinity of its E2 for the distal acceptor ubiquitin in a growing conjugate. This function of the APC/C requires its coactivator as well as conserved residues of the E2 and ubiquitin. APC/C's ability to track the tip of an emerging conjugate is required for APC/C-substrate degradation and accurate cell division. Our results suggest that RING-E3s tether the distal ubiquitin of a growing chain in proximity to the active site of their E2s, allowing them to assemble polymeric conjugates without altering their binding to substrate or E2.
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Affiliation(s)
- Aileen Kelly
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Katherine E Wickliffe
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Ling Song
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Indro Fedrigo
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Michael Rape
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA.
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34
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Chang LF, Zhang Z, Yang J, McLaughlin SH, Barford D. Molecular architecture and mechanism of the anaphase-promoting complex. Nature 2014; 513:388-393. [PMID: 25043029 PMCID: PMC4456660 DOI: 10.1038/nature13543] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 05/28/2014] [Indexed: 12/12/2022]
Abstract
The ubiquitination of cell cycle regulatory proteins by the anaphase-promoting complex/cyclosome (APC/C) controls sister chromatid segregation, cytokinesis and the establishment of the G1 phase of the cell cycle. The APC/C is an unusually large multimeric cullin-RING ligase. Its activity is strictly dependent on regulatory coactivator subunits that promote APC/C-substrate interactions and stimulate its catalytic reaction. Because the structures of many APC/C subunits and their organization within the assembly are unknown, the molecular basis for these processes is poorly understood. Here, from a cryo-electron microscopy reconstruction of a human APC/C-coactivator-substrate complex at 7.4 Å resolution, we have determined the complete secondary structural architecture of the complex. With this information we identified protein folds for structurally uncharacterized subunits, and the definitive location of all 20 APC/C subunits within the 1.2 MDa assembly. Comparison with apo APC/C shows that the coactivator promotes a profound allosteric transition involving displacement of the cullin-RING catalytic subunits relative to the degron-recognition module of coactivator and APC10. This transition is accompanied by increased flexibility of the cullin-RING subunits and enhanced affinity for UBCH10-ubiquitin, changes which may contribute to coactivator-mediated stimulation of APC/C E3 ligase activity.
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Affiliation(s)
- Lei-Fu Chang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Jing Yang
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | | | - David Barford
- Division of Structural Biology, Institute of Cancer Research, 237 Fulham Road, London, SW3 6JB, UK
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
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35
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Synergistic blockade of mitotic exit by two chemical inhibitors of the APC/C. Nature 2014; 514:646-9. [PMID: 25156254 DOI: 10.1038/nature13660] [Citation(s) in RCA: 180] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 07/04/2014] [Indexed: 02/07/2023]
Abstract
Protein machines are multi-subunit protein complexes that orchestrate highly regulated biochemical tasks. An example is the anaphase-promoting complex/cyclosome (APC/C), a 13-subunit ubiquitin ligase that initiates the metaphase-anaphase transition and mitotic exit by targeting proteins such as securin and cyclin B1 for ubiquitin-dependent destruction by the proteasome. Because blocking mitotic exit is an effective approach for inducing tumour cell death, the APC/C represents a potential novel target for cancer therapy. APC/C activation in mitosis requires binding of Cdc20 (ref. 5), which forms a co-receptor with the APC/C to recognize substrates containing a destruction box (D-box). Here we demonstrate that we can synergistically inhibit APC/C-dependent proteolysis and mitotic exit by simultaneously disrupting two protein-protein interactions within the APC/C-Cdc20-substrate ternary complex. We identify a small molecule, called apcin (APC inhibitor), which binds to Cdc20 and competitively inhibits the ubiquitylation of D-box-containing substrates. Analysis of the crystal structure of the apcin-Cdc20 complex suggests that apcin occupies the D-box-binding pocket on the side face of the WD40-domain. The ability of apcin to block mitotic exit is synergistically amplified by co-addition of tosyl-l-arginine methyl ester, a small molecule that blocks the APC/C-Cdc20 interaction. This work suggests that simultaneous disruption of multiple, weak protein-protein interactions is an effective approach for inactivating a protein machine.
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36
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The zinc-binding region (ZBR) fragment of Emi2 can inhibit APC/C by targeting its association with the coactivator Cdc20 and UBE2C-mediated ubiquitylation. FEBS Open Bio 2014; 4:689-703. [PMID: 25161877 PMCID: PMC4141206 DOI: 10.1016/j.fob.2014.06.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 06/16/2014] [Accepted: 06/30/2014] [Indexed: 01/21/2023] Open
Abstract
Overexpression of the ZBR fragment of Emi2, but not of Emi1, induces abnormal cell division. The Emi2 ZBR fragment impairs the association of the coactivator Cdc20 with APC/C. The Emi2 ZBR fragment inhibits ubiquitylation by the cullin-RING of APC/C and E2C. The Emi2 ZBR-specific residues for APC/C inhibitory activity have been identified.
Anaphase-promoting complex or cyclosome (APC/C) is a multisubunit ubiquitin ligase E3 that targets cell-cycle regulators. Cdc20 is required for full activation of APC/C in M phase, and mediates substrate recognition. In vertebrates, Emi2/Erp1/FBXO43 inhibits APC/C-Cdc20, and functions as a cytostatic factor that causes long-term M phase arrest of mature oocytes. In this study, we found that a fragment corresponding to the zinc-binding region (ZBR) domain of Emi2 inhibits cell-cycle progression, and impairs the association of Cdc20 with the APC/C core complex in HEK293T cells. Furthermore, we revealed that the ZBR fragment of Emi2 inhibits in vitro ubiquitin chain elongation catalyzed by the APC/C cullin-RING ligase module, the ANAPC2–ANAPC11 subcomplex, in combination with the ubiquitin chain-initiating E2, E2C/UBE2C/UbcH10. Structural analyses revealed that the Emi2 ZBR domain uses different faces for the two mechanisms. Thus, the double-faced ZBR domain of Emi2 antagonizes the APC/C function by inhibiting both the binding with the coactivator Cdc20 and ubiquitylation mediated by the cullin-RING ligase module and E2C. In addition, the tail region between the ZBR domain and the C-terminal RL residues [the post-ZBR (PZ) region] interacts with the cullin subunit, ANAPC2. In the case of the ZBR fragment of the somatic paralogue of Emi2, Emi1/FBXO5, these inhibitory activities against cell division and ubiquitylation were not observed. Finally, we identified two sets of key residues in the Emi2 ZBR domain that selectively exert each of the dual Emi2-specific modes of APC/C inhibition, by their mutation in the Emi2 ZBR domain and their transplantation into the Emi1 ZBR domain.
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37
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Activation of the APC/C ubiquitin ligase by enhanced E2 efficiency. Curr Biol 2014; 24:1556-62. [PMID: 24930963 DOI: 10.1016/j.cub.2014.05.052] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/21/2014] [Accepted: 05/22/2014] [Indexed: 01/20/2023]
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a protein-ubiquitin ligase (E3) that initiates the final events of mitosis by catalyzing the ubiquitination and proteasomal destruction of securin, cyclins, and other substrates [1, 2]. Like other members of the RING family of E3s [3, 4], the APC/C catalyzes direct ubiquitin transfer from an E2-ubiquitin conjugate (E2-Ub) to lysine residues on the protein substrate. The APC/C is activated at specific cell-cycle stages by association with an activator subunit, Cdc20 or Cdh1, which provides binding sites for specific substrate sequence motifs, or degrons. Activator might also stimulate catalytic activity [5, 6], but the underlying mechanisms are not known. Here, we dissected activator function using an artificial fusion substrate in which the N-terminal region of securin was linked to an APC/C core subunit. This fusion substrate bound tightly to the APC/C and was ubiquitinated at a low rate in the absence of activator. Ubiquitination of this substrate was stimulated by activator, due primarily to a dramatic stimulation of E2 sensitivity (Km) and catalytic rate (kcat), which together resulted in a 670-fold stimulation of kcat/Km. Thus, activator is not simply a substrate adaptor, but also enhances catalysis by promoting a more efficient interaction with the E2-Ub. Interestingly, full E2 stimulation required activator interaction with degron motifs on the substrate. We conclude that formation of a complete APC/C-activator-substrate complex leads to a major enhancement of E2 efficiency, providing an unusual substrate-assisted catalytic mechanism that limits efficient ubiquitin transfer to specific substrates.
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38
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Sanhaji M, Ritter A, Belsham HR, Friel CT, Roth S, Louwen F, Yuan J. Polo-like kinase 1 regulates the stability of the mitotic centromere-associated kinesin in mitosis. Oncotarget 2014; 5:3130-44. [PMID: 24931513 PMCID: PMC4102797 DOI: 10.18632/oncotarget.1861] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 03/24/2014] [Indexed: 12/13/2022] Open
Abstract
Proper bi-orientation of chromosomes is critical for the accurate segregation of chromosomes in mitosis. A key regulator of this process is MCAK, the mitotic centromere-associated kinesin. During mitosis the activity and localization of MCAK are regulated by mitotic key kinases including Plk1 and Aurora B. We show here that S621 in the MCAK's C-terminal domain is the major phosphorylation site for Plk1. This phosphorylation regulates MCAK's stability and facilitates its recognition by the ubiquitin/proteasome dependent APC/C(Cdc20) pathway leading to its D-box dependent degradation in mitosis. While phosphorylation of S621 does not directly affect its microtubule depolymerising activity, loss of Plk1 phosphorylation on S621 indirectly enhances its depolymerization activity in vivo by stabilizing MCAK, leading to an increased level of protein. Interfering with phosphorylation at S621 causes spindle formation defects and chromosome misalignments. Therefore, this study suggests a new mechanism by which Plk1 regulates MCAK: by regulating its degradation and hence controlling its turnover in mitosis.
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Affiliation(s)
- Mourad Sanhaji
- Department of Gynecology and Obstetrics, School of Medicine, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
| | - Andreas Ritter
- Department of Gynecology and Obstetrics, School of Medicine, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
| | - Hannah R. Belsham
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom
| | - Claire T. Friel
- School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, NG7 2UH, United Kingdom
| | - Susanne Roth
- Department of Gynecology and Obstetrics, School of Medicine, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
| | - Frank Louwen
- Department of Gynecology and Obstetrics, School of Medicine, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
| | - Juping Yuan
- Department of Gynecology and Obstetrics, School of Medicine, J. W. Goethe-University, Theodor-Stern-Kai 7, D-60590 Frankfurt, Germany
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He Y, Tollini L, Kim TH, Itahana Y, Zhang Y. The anaphase-promoting complex/cyclosome is an E3 ubiquitin ligase for Mdm2. Cell Cycle 2014; 13:2101-9. [PMID: 24804778 DOI: 10.4161/cc.29106] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The Mdm2 proto-oncoprotein is the primary negative regulator for p53. While it is believed that Mdm2 degradation is regulated via its own E3 ubiquitin ligase activity, recent development of knock-in mouse models demonstrates that Mdm2 E3 ligase function is dispensable for self-degradation in vivo. Here, we show that the anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase for Mdm2 degradation. We demonstrate that APC2, a scaffold subunit of APC/C, binds to Mdm2 and is required for Mdm2 polyubiquitination and proteasomal degradation. Downregulation of APC2 by RNAi results in transcription-independent accumulation of Mdm2 and attenuation of stress-induced p53 stabilization, leading to decreased senescence and increased cell survival. Furthermore, APC2 expression is frequently downregulated in human cancers; in tumor cell lines, APC2 downregulation correlates with Mdm2 overexpression. Our study shows the regulation of Mdm2 by the E3 ubiquitin ligase APC/C and has important therapeutic implications for tumors with Mdm2 overexpression.
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Affiliation(s)
- Yizhou He
- Department of Radiation Oncology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Lineberger Comprehensive Cancer Center; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Curriculum in Genetics and Molecular Biology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Laura Tollini
- Department of Radiation Oncology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Lineberger Comprehensive Cancer Center; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Curriculum in Genetics and Molecular Biology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Tae-Hyung Kim
- Department of Radiation Oncology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Lineberger Comprehensive Cancer Center; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Yoko Itahana
- Department of Radiation Oncology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Lineberger Comprehensive Cancer Center; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA
| | - Yanping Zhang
- Department of Radiation Oncology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Lineberger Comprehensive Cancer Center; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Department of Pharmacology; School of Medicine; University of North Carolina at Chapel Hill; Chapel Hill, NC USA; Laboratory of Biological Cancer Therapy; Xuzhou Medical College; Xuzhou, China
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40
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Zhang J, Wan L, Dai X, Sun Y, Wei W. Functional characterization of Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligases in tumorigenesis. Biochim Biophys Acta Rev Cancer 2014; 1845:277-93. [PMID: 24569229 DOI: 10.1016/j.bbcan.2014.02.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 02/09/2014] [Accepted: 02/12/2014] [Indexed: 12/25/2022]
Abstract
The Anaphase Promoting Complex/Cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that primarily governs cell cycle progression. APC/C is composed of at least 14 core subunits and recruits its substrates for ubiquitination via one of the two adaptor proteins, Cdc20 or Cdh1, in M or M/early G1 phase, respectively. Furthermore, recent studies have shed light on crucial functions for APC/C in maintaining genomic integrity, neuronal differentiation, cellular metabolism and tumorigenesis. To gain better insight into the in vivo physiological functions of APC/C in regulating various cellular processes, particularly development and tumorigenesis, a number of mouse models of APC/C core subunits, coactivators or inhibitors have been established and characterized. However, due to their essential role in cell cycle regulation, most of the germline knockout mice targeting the APC/C pathway are embryonic lethal, indicating the need for generating conditional knockout mouse models to assess the role in tumorigenesis for each APC/C signaling component in specific tissues. In this review, we will first provide a brief introduction of the ubiquitin-proteasome system (UPS) and the biochemical activities and cellular functions of the APC/C E3 ligase. We will then focus primarily on characterizing genetic mouse models used to understand the physiological roles of each APC/C signaling component in embryogenesis, cell proliferation, development and carcinogenesis. Finally, we discuss future research directions to further elucidate the physiological contributions of APC/C components during tumorigenesis and validate their potentials as a novel class of anti-cancer targets.
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Affiliation(s)
- Jinfang Zhang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Lixin Wan
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Xiangpeng Dai
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Yi Sun
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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Bessat M. Knockdown of APC/C-associated genes and its effect on viability and cell cycle of protozoan parasite of Trypanosoma brucei. Parasitol Res 2014; 113:1555-62. [PMID: 24532012 DOI: 10.1007/s00436-014-3800-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/28/2014] [Indexed: 12/20/2022]
Abstract
In the eukaryotic pathogen of Trypanosoma brucei, the anaphase promoting complex or cyclosome (APC/C) is composed of ten subunit proteins which are conserved in kinetoplastid protozoan parasites. During the course of APC/C characterization by PTP tagging and mass spectrometry, some other proteins were found to be associated in substoichiometric ratio to APC/C. These proteins could not be assigned as APC/C core components as they are below the threshold imposed by mass spectrometry identification and therefore they are termed non-core APC/C-associated proteins. Here in this study, functional roles of these proteins were investigated through reverse genetics approach. mRNAs of protein-encoding genes were individually knocked down by RNA interference and the resulting phenotypes were assayed through functional assays such as growth curve, cell cycle progression by flow cytometry, and DNA profiles by DAPI staining and microscopy examination. Based on the presented data, these proteins are playing essential functions in the cell biology of T. brucei; and more specifically, in regulating its cell cycle progression. Thus, the non-core APC/C-associated proteins appear to play important roles in complementing APC/C specialized function in the cell cycle of T. brucei.
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Affiliation(s)
- Mohamed Bessat
- Department of Parasitology, Faculty of Veterinary Medicine, Alexandria University, P.O. Box 22758, Edfina-Rasheed Line, Behaira, Egypt,
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42
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Hein JB, Nilsson J. Stable MCC binding to the APC/C is required for a functional spindle assembly checkpoint. EMBO Rep 2014; 15:264-72. [PMID: 24464857 DOI: 10.1002/embr.201337496] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The spindle assembly checkpoint (SAC) delays progression into anaphase until all chromosomes have aligned on the metaphase plate by inhibiting Cdc20, the mitotic co-activator of the APC/C. Mad2 and BubR1 bind and inhibit Cdc20, thereby forming the mitotic checkpoint complex (MCC), which can bind stably to the APC/C. Whether MCC formation per se is sufficient for a functional SAC or MCC association with the APC/C is required remains unclear. Here, we analyze the role of two conserved motifs in Cdc20, IR and C-Box, in binding of the MCC to the APC/C. Mutants in both motifs assemble the MCC normally, but IR motif integrity is particularly important for stable binding to the APC/C. Cells expressing Cdc20 with a mutated IR motif have a compromised SAC, as uninhibited Cdc20 can compete with the MCC for APC/C binding and activate it. We thus show that stable MCC association with the APC/C is critical for a functional SAC.
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Affiliation(s)
- Jamin B Hein
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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43
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Zhang Z, Chang L, Yang J, Conin N, Kulkarni K, Barford D. The four canonical tpr subunits of human APC/C form related homo-dimeric structures and stack in parallel to form a TPR suprahelix. J Mol Biol 2013; 425:4236-48. [PMID: 23583778 PMCID: PMC3898896 DOI: 10.1016/j.jmb.2013.04.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 03/28/2013] [Accepted: 04/05/2013] [Indexed: 12/18/2022]
Abstract
The anaphase-promoting complex or cyclosome (APC/C) is a large E3 RING-cullin ubiquitin ligase composed of between 14 and 15 individual proteins. A striking feature of the APC/C is that only four proteins are involved in directly recognizing target proteins and catalyzing the assembly of a polyubiquitin chain. All other subunits, which account for >80% of the mass of the APC/C, provide scaffolding functions. A major proportion of these scaffolding subunits are structurally related. In metazoans, there are four canonical tetratricopeptide repeat (TPR) proteins that form homo-dimers (Apc3/Cdc27, Apc6/Cdc16, Apc7 and Apc8/Cdc23). Here, we describe the crystal structure of the N-terminal homo-dimerization domain of Schizosaccharomyces pombe Cdc23 (Cdc23(Nterm)). Cdc23(Nterm) is composed of seven contiguous TPR motifs that self-associate through a related mechanism to those of Cdc16 and Cdc27. Using the Cdc23(Nterm) structure, we generated a model of full-length Cdc23. The resultant "V"-shaped molecule docks into the Cdc23-assigned density of the human APC/C structure determined using negative stain electron microscopy (EM). Based on sequence conservation, we propose that Apc7 forms a homo-dimeric structure equivalent to those of Cdc16, Cdc23 and Cdc27. The model is consistent with the Apc7-assigned density of the human APC/C EM structure. The four canonical homo-dimeric TPR proteins of human APC/C stack in parallel on one side of the complex. Remarkably, the uniform relative packing of neighboring TPR proteins generates a novel left-handed suprahelical TPR assembly. This finding has implications for understanding the assembly of other TPR-containing multimeric complexes.
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Affiliation(s)
| | | | | | | | - Kiran Kulkarni
- Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
| | - David Barford
- Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
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A eukaryotic molecular target candidate of roxithromycin: fungal differentiation as a sensitive drug target analysis system. Biosci Biotechnol Biochem 2013; 77:1539-47. [PMID: 23832352 DOI: 10.1271/bbb.130210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Roxithromycin (RXM), active against prokaryotes, has beneficial side effects such as anti-cancer activities on mammalian cells, but the mechanisms underlying these effects remain unclear. We found that RXM inhibited the cellular differentiation of the rice blast fungus Magnaporthe oryzae. Hence, we screened the targets of RXM by the T7 phage display method with fungal genomic DNA, and identified MoCDC27 (M. oryzae Cell Division Cycle 27) as a candidate. We generated mocdc27 knockdown mutants that the appressoria formation was less affected by RXM. A complemented mutant restored sensitivity against RXM to the level of the wild type. These results suggest that MoCDC27 was involved in the inhibition of appressorium formation by RXM, and that the complex of RXM-MoCDC27 affected another molecule involved in appressorium formation. The T7 phage display method with fungal genomic DNA can be a useful tool in the quest for drug target.
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Mutually dependent degradation of Ama1p and Cdc20p terminates APC/C ubiquitin ligase activity at the completion of meiotic development in yeast. Cell Div 2013; 8:9. [PMID: 23816140 PMCID: PMC3734102 DOI: 10.1186/1747-1028-8-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 06/12/2013] [Indexed: 12/18/2022] Open
Abstract
Background The execution of meiotic nuclear divisions in S. cerevisiae is regulated by protein degradation mediated by the anaphase promoting complex/cyclosome (APC/C) ubiquitin ligase. The correct timing of APC/C activity is essential for normal chromosome segregation. During meiosis, the APC/C is activated by the association of either Cdc20p or the meiosis-specific factor Ama1p. Both Ama1p and Cdc20p are targeted for degradation as cells exit meiosis II with Cdc20p being destroyed by APC/CAma1. In this study we investigated how Ama1p is down regulated at the completion of meiosis. Findings Here we show that Ama1p is a substrate of APC/CCdc20 but not APC/CCdh1 in meiotic cells. Cdc20p binds Ama1p in vivo and APC/CCdc20 ubiquitylates Ama1p in vitro. Ama1p ubiquitylation requires one of two degradation motifs, a D-box and a “KEN-box” like motif called GxEN. Finally, Ama1p degradation does not require its association with the APC/C via its conserved APC/C binding motifs (C-box and IR) and occurs simultaneously with APC/CAma1-mediated Cdc20p degradation. Conclusions Unlike the cyclical nature of mitotic cell division, meiosis is a linear pathway leading to the production of quiescent spores. This raises the question of how the APC/C is reset prior to spore germination. This and a previous study revealed that Cdc20p and Ama1p direct each others degradation via APC/C-dependent degradation. These findings suggest a model that the APC/C is inactivated by mutual degradation of the activators. In addition, these results support a model in which Ama1p and Cdc20p relocate to the substrate address within the APC/C cavity prior to degradation.
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Abstract
Viruses commonly manipulate cell cycle progression to create cellular conditions that are most beneficial to their replication. To accomplish this feat, viruses often target critical cell cycle regulators in order to have maximal effect with minimal input. One such master regulator is the large, multisubunit E3 ubiquitin ligase anaphase-promoting complex (APC) that targets effector proteins for ubiquitination and proteasome degradation. The APC is essential for cells to progress through anaphase, exit from mitosis, and prevent a premature entry into S phase. These far-reaching effects of the APC on the cell cycle are through its ability to target a number of substrates, including securin, cyclin A, cyclin B, thymidine kinase, geminin, and many others. Recent studies have identified several proteins from a number of viruses that can modulate APC activity by different mechanisms, highlighting the potential of the APC in driving viral replication or pathogenesis. Most notably, human cytomegalovirus (HCMV) protein pUL21a was recently identified to disable the APC via a novel mechanism by targeting APC subunits for degradation, both during virus infection and in isolation. Importantly, HCMV lacking both viral APC regulators is significantly attenuated, demonstrating the impact of the APC on a virus infection. Work in this field will likely lead to novel insights into viral replication and pathogenesis and APC function and identify novel antiviral and anticancer targets. Here we review viral mechanisms to regulate the APC, speculate on their roles during infection, and identify questions to be addressed in future studies.
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Abstract
The anaphase-promoting complex or cyclosome (APC/C) is a conserved, multisubunit E3 ubiquitin (Ub) ligase that is active both in dividing and in postmitotic cells. Its contributions to life are especially well studied in the domain of cell division, in which the APC/C lies at the epicenter of a regulatory network that controls the directionality and timing of cell cycle events. Biochemical and structural work is shedding light on the overall organization of APC/C subunits and on the mechanism of substrate recognition and Ub chain initiation and extension as well as on the molecular mechanisms of a checkpoint that seizes control of APC/C activity during mitosis. Here, we review how these recent advancements are modifying our understanding of the APC/C.
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Affiliation(s)
- Ivana Primorac
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany
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48
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Barford D, Takagi Y, Schultz P, Berger I. Baculovirus expression: tackling the complexity challenge. Curr Opin Struct Biol 2013; 23:357-64. [PMID: 23628287 PMCID: PMC7125881 DOI: 10.1016/j.sbi.2013.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 03/18/2013] [Accepted: 03/29/2013] [Indexed: 10/26/2022]
Abstract
Most essential functions in eukaryotic cells are catalyzed by complex molecular machines built of many subunits. To fully understand their biological function in health and disease, it is imperative to study these machines in their entirety. The provision of many essential multiprotein complexes of higher eukaryotes including humans, can be a considerable challenge, as low abundance and heterogeneity often rule out their extraction from native source material. The baculovirus expression vector system (BEVS), specifically tailored for multiprotein complex production, has proven itself to be uniquely suited for overcoming this impeding bottleneck. Here we highlight recent major achievements in multiprotein complex structure research that were catalyzed by this versatile recombinant complex expression tool.
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Affiliation(s)
- David Barford
- Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK
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49
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Bessat M, Knudsen G, Burlingame AL, Wang CC. A minimal anaphase promoting complex/cyclosome (APC/C) in Trypanosoma brucei. PLoS One 2013; 8:e59258. [PMID: 23533609 PMCID: PMC3606461 DOI: 10.1371/journal.pone.0059258] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 02/13/2013] [Indexed: 12/16/2022] Open
Abstract
The anaphase-promoting complex/cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that initiates chromosome segregation and mitotic exit by targeting critical cell-cycle regulators for proteolytic destruction. Previously, seven APC/C subunit homologues were identified in the genome of Trypanosoma brucei. In the present study, we tested five of them in yeast complementation studies and found none of them capable of complementing the yeast mutants lacking the corresponding subunits, suggesting significant discrepancies between the two APC/C’s. Subunit homologues of mitotic checkpoint complex (MCC) have not yet been identified in T. brucei, raising the possibility that a MCC-APC/C complex equivalent may not exist in T. brucei. We performed tandem affinity purification of the protein complex containing a APC1 fusion protein expressed in the cells enriched in different phases of the cell cycle of procyclic form T. brucei, and compared their protein profiles using LC-MS/MS analyses. The seven putative APC/C subunits were identified in the protein complex throughout the cell cycle together with three additional proteins designated the associated proteins (AP) AP1, AP2 and AP3. Abundance of the 10 proteins remained relatively unchanged throughout the cell cycle, suggesting that they are the core subunits of APC/C. AP1 turned out to be a homologue of APC4. An RNAi knockdown of APC4 and AP3 showed no detectable cellular phenotype, whereas an AP2 knockdown enriched the cells in G2/M phase. The AP2-depleted cells showed stabilized mitotic cyclin B. An accumulation of poly-ubiquitinated cyclin B was indicated in the cells treated with the proteasome inhibitor MG132, demonstrating the involvement of proteasome in degrading poly-ubiquitinated cyclin B. In all, a 10-subunit APC/C machinery with a conserved function is identified in T. brucei without linking to a MCC-like complex, thus indicating a unique T. brucei APC/C.
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Affiliation(s)
- Mohamed Bessat
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
| | - Giselle Knudsen
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
| | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
| | - Ching C. Wang
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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50
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Sedgwick GG, Hayward DG, Di Fiore B, Pardo M, Yu L, Pines J, Nilsson J. Mechanisms controlling the temporal degradation of Nek2A and Kif18A by the APC/C-Cdc20 complex. EMBO J 2013; 32:303-14. [PMID: 23288039 PMCID: PMC3553385 DOI: 10.1038/emboj.2012.335] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 11/26/2012] [Indexed: 12/23/2022] Open
Abstract
The Anaphase Promoting Complex/Cyclosome (APC/C) in complex with its co-activator Cdc20 is responsible for targeting proteins for ubiquitin-mediated degradation during mitosis. The activity of APC/C-Cdc20 is inhibited during prometaphase by the Spindle Assembly Checkpoint (SAC) yet certain substrates escape this inhibition. Nek2A degradation during prometaphase depends on direct binding of Nek2A to the APC/C via a C-terminal MR dipeptide but whether this motif alone is sufficient is not clear. Here, we identify Kif18A as a novel APC/C-Cdc20 substrate and show that Kif18A degradation depends on a C-terminal LR motif. However in contrast to Nek2A, Kif18A is not degraded until anaphase showing that additional mechanisms contribute to Nek2A degradation. We find that dimerization via the leucine zipper, in combination with the MR motif, is required for stable Nek2A binding to and ubiquitination by the APC/C. Nek2A and the mitotic checkpoint complex (MCC) have an overlap in APC/C subunit requirements for binding and we propose that Nek2A binds with high affinity to apo-APC/C and is degraded by the pool of Cdc20 that avoids inhibition by the SAC.
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Affiliation(s)
- Garry G Sedgwick
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
- BRIC, University of Copenhagen, Copenhagen, Denmark
| | - Daniel G Hayward
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
- BRIC, University of Copenhagen, Copenhagen, Denmark
| | - Barbara Di Fiore
- The Gurdon Institute and Department of Zoology, University of Cambridge, Cambridge, UK
| | - Mercedes Pardo
- Proteomics Mass Spectrometry Laboratory, The Wellcome Trust Sanger Institute, Cambridge, UK
| | - Lu Yu
- Proteomics Mass Spectrometry Laboratory, The Wellcome Trust Sanger Institute, Cambridge, UK
| | - Jonathon Pines
- The Gurdon Institute and Department of Zoology, University of Cambridge, Cambridge, UK
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Science, University of Copenhagen, Copenhagen, Denmark
- BRIC, University of Copenhagen, Copenhagen, Denmark
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