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Tong H, Liu X, Peng C, Shen B, Zhu Z. Silencing of KNTC1 inhibits hepatocellular carcinoma cells progression via suppressing PI3K/Akt pathway. Cell Signal 2023; 101:110498. [PMID: 36273753 DOI: 10.1016/j.cellsig.2022.110498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 11/30/2022]
Abstract
Kinetochore associated 1 (KNTC1) encodes a kinetochore component in Rod-Zwilch-ZW10 (RZZ) complex which is essential for the segregation of sister chromatids during mitosis and participates in the spindle checkpoint. Recent research demonstrated that kinetochore proteins may be potential biomarkers and may contribute to the development of human malignancies. Our immunohistochemistry experiment showed that KNTC1 was highly expressed in hepatocellular carcinoma (HCC) tissues and correlated with terrible prognosis, indicating that KNTC1 acts a pivotal role in HCC development. Furthermore, lentivirus delivered short hairpin RNA (shRNA) KNTC1 (Lv-shKNTC1) was applied to infect BEL-7404 and SK-HEP-1 to identify roles of KNTC1 on HCC. Lv-shKNTC1 cells showed reduced proliferation ability, increased apoptosis and decreased migration ability. In vivo experiments suggested that xenografts grow significantly slower upon the silencing of KNTC1. Mechanistically, the protein levels of PIK3CA, p-Akt, CCND1, CDK6 are all down-regulated in Lv-KNTC1 cells and the Lv-shKNTC1 tumor tissues of nude mice. Therefore, KNTC1 may affect the biological activity of HCC cells through PI3K/Akt signaling pathway. Further studies revealed that ZW10 is a pivotal protein that participates in KNTC1-induced regulation of PI3K/Akt signaling pathway. In summary, the key finding of this report highlighted the significance of KNTC1 in tumor regression of HCC, demonstrating KNTC1 as an innovative target for adjuvant treatment of HCC.
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Affiliation(s)
- Hui Tong
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaohui Liu
- CNRS-LIA124, Sino-French Research Center for Life Sciences and Genomics, State Key Laboratory of Medical Genomics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chenghong Peng
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Baiyong Shen
- Department of General Surgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Zhecheng Zhu
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
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2
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BUBs Are New Biomarkers of Promoting Tumorigenesis and Affecting Prognosis in Breast Cancer. DISEASE MARKERS 2022; 2022:2760432. [PMID: 35493295 PMCID: PMC9053761 DOI: 10.1155/2022/2760432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/25/2022] [Indexed: 12/31/2022]
Abstract
Background A tumor occurs because of abnormal cell multiplication caused by many variables like a significant disturbance in the regulation of cell growth and the instability of chromosome mitosis. Budding uninhibited by benzimidazoles 1 (BUB1), BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B), and budding uninhibited by benzimidazoles 3 (BUB3) are key regulators of mitosis, and their abnormal expression is highly correlated with breast cancer (BrCa), sarcoma, hepatic carcinoma, and other malignant tumors. However, the occurrence of BUBs (BUB1, BUB1B, and BUB3) and the development of BrCa have not been systematically explained. Methods Find out the target gene by looking up literature on PubMed and CNKI. Using the R software, TCGA, GEO, Kaplan-Meier Plotter, TIMER, and other databases, we studied the level of transcription, genetic changes, and physiological functions of BUBs in BrCa patients and their relationship with the origin, development, prognosis, immunity, and drug resistance of BrCa patients. Findings. We found that the high expression level of BUBs in BrCa tissues proposed a poor prognosis. The multivariate Cox regression analysis suggested that BUB1B and BUB3 might be independent prognostic factors of BrCa. In addition, the Metascape functional enrichment analysis showed that BUBs may be involved in the composition of the spindle, chromosome, and other structures and play a role in mitosis, sister chromatid separation, and other processes. Pathway enrichment suggests that BUBs may affect the cell cycle and lead to abnormal proliferation. Meanwhile, we also found that BUB3 can negatively regulate B lymphocytes, and BUB1 and BUB1B inhibit immune responses by promoting the secretion level of checkpoint molecules of the immune system, leading to immune escape of tumor cells. Conclusion We speculate that BUB1, BUB1B, and BUB3 may be therapeutic targets for BrCa patients and also provide new therapeutic strategies for BrCa treatment.
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3
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Carvalhal S, Bader I, Rooimans MA, Oostra AB, Balk JA, Feichtinger RG, Beichler C, Speicher MR, van Hagen JM, Waisfisz Q, van Haelst M, Bruijn M, Tavares A, Mayr JA, Wolthuis RMF, Oliveira RA, de Lange J. Biallelic BUB1 mutations cause microcephaly, developmental delay, and variable effects on cohesion and chromosome segregation. SCIENCE ADVANCES 2022; 8:eabk0114. [PMID: 35044816 PMCID: PMC8769543 DOI: 10.1126/sciadv.abk0114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Budding uninhibited by benzimidazoles (BUB1) contributes to multiple mitotic processes. Here, we describe the first two patients with biallelic BUB1 germline mutations, who both display microcephaly, intellectual disability, and several patient-specific features. The identified mutations cause variable degrees of reduced total protein level and kinase activity, leading to distinct mitotic defects. Both patients’ cells show prolonged mitosis duration, chromosome segregation errors, and an overall functional spindle assembly checkpoint. However, while BUB1 levels mostly affect BUBR1 kinetochore recruitment, impaired kinase activity prohibits centromeric recruitment of Aurora B, SGO1, and TOP2A, correlating with anaphase bridges, aneuploidy, and defective sister chromatid cohesion. We do not observe accelerated cohesion fatigue. We hypothesize that unresolved DNA catenanes increase cohesion strength, with concomitant increase in anaphase bridges. In conclusion, BUB1 mutations cause a neurodevelopmental disorder, with clinical and cellular phenotypes that partially resemble previously described syndromes, including autosomal recessive primary microcephaly, mosaic variegated aneuploidy, and cohesinopathies.
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Affiliation(s)
- Sara Carvalhal
- Instituto Gulbenkian de Ciência, R. Q.ta Grande 6, 2780-156 Oeiras, Portugal
- Algarve Biomedical Center Research Institute, Universidade do Algarve, 8005-139 Faro, Portugal
- Centre for Biomedical Research, Universidade do Algarve, 8005-139 Faro, Portugal
| | - Ingrid Bader
- Unit of Clinical Genetics, Paracelsus Medical University, Salzburg, Austria
| | - Martin A. Rooimans
- Cancer Center Amsterdam, Amsterdam University Medical Centers, Oncogenetics Section, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
| | - Anneke B. Oostra
- Cancer Center Amsterdam, Amsterdam University Medical Centers, Oncogenetics Section, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
| | - Jesper A. Balk
- Cancer Center Amsterdam, Amsterdam University Medical Centers, Oncogenetics Section, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
| | - René G. Feichtinger
- Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Christine Beichler
- Institute of Human Genetics, Diagnostic and Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria
| | - Michael R. Speicher
- Institute of Human Genetics, Diagnostic and Research Center for Molecular BioMedicine, Medical University of Graz, Graz, Austria
| | - Johanna M. van Hagen
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
| | - Quinten Waisfisz
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
| | - Mieke van Haelst
- Department of Clinical Genetics, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
| | - Martijn Bruijn
- Northwest Clinics, Wilhelminalaan 12, 1815 JD Alkmaar, Netherlands
| | - Alexandra Tavares
- Instituto Gulbenkian de Ciência, R. Q.ta Grande 6, 2780-156 Oeiras, Portugal
| | - Johannes A. Mayr
- Department of Pediatrics, University Hospital Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Rob M. F. Wolthuis
- Cancer Center Amsterdam, Amsterdam University Medical Centers, Oncogenetics Section, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
| | - Raquel A. Oliveira
- Instituto Gulbenkian de Ciência, R. Q.ta Grande 6, 2780-156 Oeiras, Portugal
- Corresponding author. (R.A.O.); (J.d.L.)
| | - Job de Lange
- Cancer Center Amsterdam, Amsterdam University Medical Centers, Oncogenetics Section, De Boelelaan 1118, 1081 HV Amsterdam, Netherlands
- Corresponding author. (R.A.O.); (J.d.L.)
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4
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Lin T, Zhang Y, Lin Z, Peng L. ZWINT is a Promising Therapeutic Biomarker Associated with the Immune Microenvironment of Hepatocellular Carcinoma. Int J Gen Med 2021; 14:7487-7501. [PMID: 34744456 PMCID: PMC8566006 DOI: 10.2147/ijgm.s340057] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 10/20/2021] [Indexed: 12/15/2022] Open
Abstract
Background The prognosis of patients with advanced hepatocellular carcinoma (HCC) is still poor, effective therapeutic targets are needed. ZW10 interacting kinetochore protein (Zwint) is an essential component of the mitotic spindle checkpoint and is upregulated in cancers. Disappointing, the role of ZWINT in HCC has not been fully illuminated. Methods Multiple tools, including TIMER2.0, Oncomine, GEPIA2, UALCAN, LinkedOmics, Kaplan-Meier Plotter, cBioPortal, and MethSurv, etc. were applied to comprehensively analyze the expression, genetic alternations, clinicopathological relevance, prognostic value, and DNA methylation of ZWINT, along with its correlations with immune infiltration in HCC. Besides, gene set enrichment analysis (GSEA) and protein-protein interaction (PPI) analysis were performed for the correlated genes of ZWINT, closely interconnected clusters and hub proteins in the PPI network were discovered to learn the underlying biological mechanisms. Results We found ZWINT was significantly upregulated in diverse cancers including HCC, compared with the corresponding normal controls. ZWINT upregulation was significantly associated with unfavorable clinicopathological features and survivals of HCC patients. Genetic alternations of ZWINT frequently occurred, which were linked to worse outcomes of HCC patients. The results of GSEA displayed ZWINT and its correlated genes might be components of condensed chromosomes and spindles, which participated in biological processes and signaling pathways involving DNA replication, cytokinesis, and cell cycle checkpoint, etc. Three highly interconnected clusters and 10 hub proteins were identified from the PPI network constructed with the correlated genes of ZWINT. Moreover, ZWINT expression was found positively correlated with infiltration levels of various immune cells, especially myeloid-derived suppressor cells. Conclusion This study demonstrated ZWINT might be a promising unfavorable prognostic biomarker and a therapeutic target of HCC, which could regulate HCC progression through cell division and immunosuppression.
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Affiliation(s)
- Tong Lin
- The Fourth Clinical Medical School, Guangzhou University of Chinese Medicine, Shenzhen, People's Republic of China
| | - Yingzhao Zhang
- The Fourth Clinical Medical School, Guangzhou University of Chinese Medicine, Shenzhen, People's Republic of China
| | - Zhimei Lin
- The Fourth Clinical Medical School, Guangzhou University of Chinese Medicine, Shenzhen, People's Republic of China
| | - Lisheng Peng
- Department of Science and Education, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, People's Republic of China
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5
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Kops GJPL, Snel B, Tromer EC. Evolutionary Dynamics of the Spindle Assembly Checkpoint in Eukaryotes. Curr Biol 2021; 30:R589-R602. [PMID: 32428500 DOI: 10.1016/j.cub.2020.02.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The tremendous diversity in eukaryotic life forms can ultimately be traced back to evolutionary modifications at the level of molecular networks. Deep understanding of these modifications will not only explain cellular diversity, but will also uncover different ways to execute similar processes and expose the evolutionary 'rules' that shape the molecular networks. Here, we review the evolutionary dynamics of the spindle assembly checkpoint (SAC), a signaling network that guards fidelity of chromosome segregation. We illustrate how the interpretation of divergent SAC systems in eukaryotic species is facilitated by combining detailed molecular knowledge of the SAC and extensive comparative genome analyses. Ultimately, expanding this to other core cellular systems and experimentally interrogating such systems in organisms from all major lineages may start outlining the routes to and eventual manifestation of the cellular diversity of eukaryotic life.
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Affiliation(s)
- Geert J P L Kops
- Oncode Institute, Hubrecht Institute - KNAW (Royal Netherlands Academy of Arts and Sciences) and University Medical Centre Utrecht, Utrecht, The Netherlands.
| | - Berend Snel
- Theoretical Biology and Bioinformatics, Department of Biology, Science Faculty, Utrecht University, Utrecht, The Netherlands.
| | - Eelco C Tromer
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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6
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Uehara DT, Mitsubuchi H, Inazawa J. A missense variant in NUF2, a component of the kinetochore NDC80 complex, causes impaired chromosome segregation and aneuploidy associated with microcephaly and short stature. Hum Genet 2021; 140:1047-1060. [PMID: 33721060 DOI: 10.1007/s00439-021-02273-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 02/28/2021] [Indexed: 12/11/2022]
Abstract
Mutations in proteins involved in cell division and chromosome segregation, such as microtubule-regulating, centrosomal and kinetochore proteins, are associated with microcephaly and/or short stature. In particular, the kinetochore plays an essential role in mitosis and cell division by mediating connections between chromosomal DNA and spindle microtubules. To date, only a few genes encoding proteins of the kinetochore complex have been identified as causes of syndromes that include microcephaly. We report a male patient with a rare de novo missense variant in NUF2, after trio whole-exome sequencing analysis. The patient presented with microcephaly and short stature, with additional features, such as bilateral vocal cord paralysis, micrognathia and atrial septal defect. NUF2 encodes a subunit of the NDC80 complex in the outer kinetochore, important for correct microtubule binding and spindle assembly checkpoint. The mutated residue is buried at the calponin homology (CH) domain at the N-terminus of NUF2, which interacts with the N-terminus of NDC80. The variant caused the loss of hydrophobic interactions in the core of the CH domain of NUF2, thereby impairing the stability of NDC80-NUF2. Analysis using a patient-derived lymphoblastoid cell line revealed markedly reduced protein levels of both NUF2 and NDC80, aneuploidy, increased micronuclei formation and spindle abnormality. Our findings suggest that NUF2 may be the first member of the NDC80 complex to be associated with a human disorder.
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Affiliation(s)
- Daniela Tiaki Uehara
- Department of Molecular Cytogenetics, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan
| | - Hiroshi Mitsubuchi
- Department of Neonatology, Kumamoto University Hospital, Kumamoto, Japan
| | - Johji Inazawa
- Department of Molecular Cytogenetics, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
- Bioresource Research Center, Tokyo Medical and Dental University, Tokyo, Japan.
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7
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Germline AGO2 mutations impair RNA interference and human neurological development. Nat Commun 2020; 11:5797. [PMID: 33199684 PMCID: PMC7670403 DOI: 10.1038/s41467-020-19572-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 09/21/2020] [Indexed: 12/29/2022] Open
Abstract
ARGONAUTE-2 and associated miRNAs form the RNA-induced silencing complex (RISC), which targets mRNAs for translational silencing and degradation as part of the RNA interference pathway. Despite the essential nature of this process for cellular function, there is little information on the role of RISC components in human development and organ function. We identify 13 heterozygous mutations in AGO2 in 21 patients affected by disturbances in neurological development. Each of the identified single amino acid mutations result in impaired shRNA-mediated silencing. We observe either impaired RISC formation or increased binding of AGO2 to mRNA targets as mutation specific functional consequences. The latter is supported by decreased phosphorylation of a C-terminal serine cluster involved in mRNA target release, increased formation of dendritic P-bodies in neurons and global transcriptome alterations in patient-derived primary fibroblasts. Our data emphasize the importance of gene expression regulation through the dynamic AGO2-RNA association for human neuronal development. AGO2 binds to miRNAs to repress expression of cognate target mRNAs. Here the authors report that heterozygous AGO2 mutations result in defects in neurological development and impair RNA interference.
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8
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Simmons AJ, Park R, Sterling NA, Jang MH, van Deursen JMA, Yen TJ, Cho SH, Kim S. Nearly complete deletion of BubR1 causes microcephaly through shortened mitosis and massive cell death. Hum Mol Genet 2020; 28:1822-1836. [PMID: 30668728 DOI: 10.1093/hmg/ddz022] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/14/2018] [Accepted: 01/15/2019] [Indexed: 02/06/2023] Open
Abstract
BUB-related 1 (BubR1) encoded by Budding Uninhibited by Benzimidazole 1B (BUB1B) is a crucial mitotic checkpoint protein ensuring proper segregation of chromosomes during mitosis. Mutations of BUB1B are responsible for mosaic variegated aneuploidy (MVA), a human congenital disorder characterized by extensive abnormalities in chromosome number. Although microcephaly is a prominent feature of MVA carrying the BUB1B mutation, how BubR1 deficiency disturbs neural progenitor proliferation and neuronal output and leads to microcephaly is unknown. Here we show that conditional loss of BubR1 in mouse cerebral cortex recapitulates microcephaly. BubR1-deficient cortex includes a strikingly reduced number of late-born, but not of early-born, neurons, although BubR1 expression is substantially reduced from an early stage. Importantly, absence of BubR1 decreases the proportion of neural progenitors in mitosis, specifically in metaphase, suggesting shortened mitosis owing to premature chromosome segregation. In the BubR1 mutant, massive apoptotic cell death, which is likely due to the compromised genomic integrity that results from aberrant mitosis, depletes progenitors and neurons during neurogenesis. There is no apparent alteration in centrosome number, spindle formation or primary cilia, suggesting that the major effect of BubR1 deficiency on neural progenitors is to impair the mitotic checkpoint. This finding highlights the importance of the mitotic checkpoint in the pathogenesis of microcephaly. Furthermore, the ependymal cell layer does not form in the conditional knockout, revealing an unrecognized role of BubR1 in assuring the integrity of the ventricular system, which may account for the presence of hydrocephalus in some patients.
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Affiliation(s)
- Ambrosia J Simmons
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine Temple University, Philadelphia, PA, USA.,MD/Ph.D. program, Lewis Katz School of Medicine Temple University, Philadelphia, PA, USA
| | - Raehee Park
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine Temple University, Philadelphia, PA, USA
| | - Noelle A Sterling
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine Temple University, Philadelphia, PA, USA
| | - Mi-Hyeon Jang
- Department of Neurologic Surgery, Mayo Clinic College of Medicine, Rochester, MN, USA.,Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jan M A van Deursen
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | | | - Seo-Hee Cho
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine Temple University, Philadelphia, PA, USA
| | - Seonhee Kim
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine Temple University, Philadelphia, PA, USA
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9
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Abstract
The goal of mitosis is to form two daughter cells each containing one copy of each mother cell chromosome, replicated in the previous S phase. To achieve this, sister chromatids held together back-to-back at their primary constriction, the centromere, have to interact with microtubules of the mitotic spindle so that each chromatid takes connections with microtubules emanating from opposite spindle poles (we will refer to this condition as bipolar attachment). Only once all replicated chromosomes have reached bipolar attachments can sister chromatids lose cohesion with each other, at the onset of anaphase, and move toward opposite spindle poles, being segregated into what will soon become the daughter cell nucleus. Prevention of errors in chromosome segregation is granted by a safeguard mechanism called Spindle Assembly Checkpoint (SAC). Until all chromosomes are bipolarly oriented at the equator of the mitotic spindle, the SAC prevents loss of sister chromatid cohesion, thus anaphase onset, and maintains the mitotic state by inhibiting inactivation of the major M phase promoting kinase, the cyclin B-cdk1 complex (Cdk1). Here, we review recent mechanistic insights about the circuitry that links Cdk1 to the SAC to ensure correct achievement of the goal of mitosis.
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Affiliation(s)
- Angela Flavia Serpico
- CEINGE Biotecnologie Avanzate, Naples, 80145, Italy.,DMMBM, University of Naples "Federico II", Naples, 80131, Italy
| | - Domenico Grieco
- CEINGE Biotecnologie Avanzate, Naples, 80145, Italy.,Department of Pharmacy, University of Naples "Federico II", Naples, 80131, Italy
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10
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The Mitotic Apparatus and Kinetochores in Microcephaly and Neurodevelopmental Diseases. Cells 2019; 9:cells9010049. [PMID: 31878213 PMCID: PMC7016623 DOI: 10.3390/cells9010049] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/18/2019] [Accepted: 12/21/2019] [Indexed: 12/15/2022] Open
Abstract
Regulators of mitotic division, when dysfunctional or expressed in a deregulated manner (over- or underexpressed) in somatic cells, cause chromosome instability, which is a predisposing condition to cancer that is associated with unrestricted proliferation. Genes encoding mitotic regulators are growingly implicated in neurodevelopmental diseases. Here, we briefly summarize existing knowledge on how microcephaly-related mitotic genes operate in the control of chromosome segregation during mitosis in somatic cells, with a special focus on the role of kinetochore factors. Then, we review evidence implicating mitotic apparatus- and kinetochore-resident factors in the origin of congenital microcephaly. We discuss data emerging from these works, which suggest a critical role of correct mitotic division in controlling neuronal cell proliferation and shaping the architecture of the central nervous system.
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11
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Ling YH, Lin Z, Yuen KWY. Genetic and epigenetic effects on centromere establishment. Chromosoma 2019; 129:1-24. [PMID: 31781852 DOI: 10.1007/s00412-019-00727-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/24/2019] [Accepted: 10/10/2019] [Indexed: 01/19/2023]
Abstract
Endogenous chromosomes contain centromeres to direct equal chromosomal segregation in mitosis and meiosis. The location and function of existing centromeres is usually maintained through cell cycles and generations. Recent studies have investigated how the centromere-specific histone H3 variant CENP-A is assembled and replenished after DNA replication to epigenetically propagate the centromere identity. However, existing centromeres occasionally become inactivated, with or without change in underlying DNA sequences, or lost after chromosomal rearrangements, resulting in acentric chromosomes. New centromeres, known as neocentromeres, may form on ectopic, non-centromeric chromosomal regions to rescue acentric chromosomes from being lost, or form dicentric chromosomes if the original centromere is still active. In addition, de novo centromeres can form after chromatinization of purified DNA that is exogenously introduced into cells. Here, we review the phenomena of naturally occurring and experimentally induced new centromeres and summarize the genetic (DNA sequence) and epigenetic features of these new centromeres. We compare the characteristics of new and native centromeres to understand whether there are different requirements for centromere establishment and propagation. Based on our understanding of the mechanisms of new centromere formation, we discuss the perspectives of developing more stably segregating human artificial chromosomes to facilitate gene delivery in therapeutics and research.
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Affiliation(s)
- Yick Hin Ling
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Zhongyang Lin
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong
| | - Karen Wing Yee Yuen
- School of Biological Sciences, The University of Hong Kong, Kadoorie Biological Sciences Building, Pokfulam Road, Hong Kong.
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12
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Etemad B, Vertesy A, Kuijt TEF, Sacristan C, van Oudenaarden A, Kops GJPL. Spindle checkpoint silencing at kinetochores with submaximal microtubule occupancy. J Cell Sci 2019; 132:jcs.231589. [PMID: 31138679 DOI: 10.1242/jcs.231589] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 05/17/2019] [Indexed: 11/20/2022] Open
Abstract
The spindle assembly checkpoint (SAC) ensures proper chromosome segregation by monitoring kinetochore-microtubule interactions. SAC proteins are shed from kinetochores once stable attachments are achieved. Human kinetochores consist of hundreds of SAC protein recruitment modules and bind up to 20 microtubules, raising the question of how the SAC responds to intermediate attachment states. We show that one protein module ('RZZS-MAD1-MAD2') of the SAC is removed from kinetochores at low microtubule occupancy and remains absent at higher occupancies, while another module ('BUB1-BUBR1') is retained at substantial levels irrespective of attachment states. These behaviours reflect different silencing mechanisms: while BUB1 displacement is almost fully dependent on MPS1 inactivation, MAD1 (also known as MAD1L1) displacement is not. Artificially tuning the affinity of kinetochores for microtubules further shows that ∼50% occupancy is sufficient to shed MAD2 and silence the SAC. Kinetochores thus respond as a single unit to shut down SAC signalling at submaximal occupancy states, but retain one SAC module. This may ensure continued SAC silencing on kinetochores with fluctuating occupancy states while maintaining the ability for fast SAC re-activation.
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Affiliation(s)
- Banafsheh Etemad
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Abel Vertesy
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Timo E F Kuijt
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Carlos Sacristan
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Alexander van Oudenaarden
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
| | - Geert J P L Kops
- Oncode Institute, Hubrecht Institute - KNAW and University Medical Centre Utrecht, Utrecht, 3584 CT, The Netherlands
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