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Day M, Tetik B, Parlak M, Almeida-Hernández Y, Räschle M, Kaschani F, Siegert H, Marko A, Sanchez-Garcia E, Kaiser M, Barker IA, Pearl LH, Oliver AW, Boos D. TopBP1 utilises a bipartite GINS binding mode to support genome replication. Nat Commun 2024; 15:1797. [PMID: 38413589 PMCID: PMC10899662 DOI: 10.1038/s41467-024-45946-0] [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: 06/21/2023] [Accepted: 02/07/2024] [Indexed: 02/29/2024] Open
Abstract
Activation of the replicative Mcm2-7 helicase by loading GINS and Cdc45 is crucial for replication origin firing, and as such for faithful genetic inheritance. Our biochemical and structural studies demonstrate that the helicase activator GINS interacts with TopBP1 through two separate binding surfaces, the first involving a stretch of highly conserved amino acids in the TopBP1-GINI region, the second a surface on TopBP1-BRCT4. The two surfaces bind to opposite ends of the A domain of the GINS subunit Psf1. Mutation analysis reveals that either surface is individually able to support TopBP1-GINS interaction, albeit with reduced affinity. Consistently, either surface is sufficient for replication origin firing in Xenopus egg extracts and becomes essential in the absence of the other. The TopBP1-GINS interaction appears sterically incompatible with simultaneous binding of DNA polymerase epsilon (Polε) to GINS when bound to Mcm2-7-Cdc45, although TopBP1-BRCT4 and the Polε subunit PolE2 show only partial competitivity in binding to Psf1. Our TopBP1-GINS model improves the understanding of the recently characterised metazoan pre-loading complex. It further predicts the coordination of three molecular origin firing processes, DNA polymerase epsilon arrival, TopBP1 ejection and GINS integration into Mcm2-7-Cdc45.
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Affiliation(s)
- Matthew Day
- School of Biological and Behavioural Sciences, Blizard Institute, Queen Mary University of London, London, E1 2AT, UK.
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK.
| | - Bilal Tetik
- Molecular Genetics II, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
| | - Milena Parlak
- Molecular Genetics II, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
| | - Yasser Almeida-Hernández
- Computational Bioengineering, Fakultät Bio- und Chemieingenieurwesen, Technical University Dortmund, Emil-Figge Str. 66, 44227, Dortmund, Germany
- Computational Biochemistry, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
| | - Markus Räschle
- Molecular Genetics, Technical University Kaiserslautern, Paul-Ehrlich Straße 24, 67663, Kaiserslautern, Germany
| | - Farnusch Kaschani
- Analytics Core Facility Essen, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
- Chemical Biology, Center of Medical Biotechnology, University Duisburg-Essen, Fakultät Biologie, Essen, Germany
| | - Heike Siegert
- Molecular Genetics II, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
| | - Anika Marko
- Molecular Genetics II, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
| | - Elsa Sanchez-Garcia
- Computational Bioengineering, Fakultät Bio- und Chemieingenieurwesen, Technical University Dortmund, Emil-Figge Str. 66, 44227, Dortmund, Germany
- Computational Biochemistry, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
| | - Markus Kaiser
- Analytics Core Facility Essen, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany
- Chemical Biology, Center of Medical Biotechnology, University Duisburg-Essen, Fakultät Biologie, Essen, Germany
| | - Isabel A Barker
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK
| | - Laurence H Pearl
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK.
- Division of Structural Biology, Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London, SW1E 6BT, UK.
| | - Antony W Oliver
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9RQ, UK.
| | - Dominik Boos
- Molecular Genetics II, Center of Medical Biotechnology, University of Duisburg-Essen, Universitätsstraße 2-5, 45141, Essen, Germany.
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Khamidullina AI, Abramenko YE, Bruter AV, Tatarskiy VV. Key Proteins of Replication Stress Response and Cell Cycle Control as Cancer Therapy Targets. Int J Mol Sci 2024; 25:1263. [PMID: 38279263 PMCID: PMC10816012 DOI: 10.3390/ijms25021263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/14/2024] [Accepted: 01/17/2024] [Indexed: 01/28/2024] Open
Abstract
Replication stress (RS) is a characteristic state of cancer cells as they tend to exchange precision of replication for fast proliferation and increased genomic instability. To overcome the consequences of improper replication control, malignant cells frequently inactivate parts of their DNA damage response (DDR) pathways (the ATM-CHK2-p53 pathway), while relying on other pathways which help to maintain replication fork stability (ATR-CHK1). This creates a dependency on the remaining DDR pathways, vulnerability to further destabilization of replication and synthetic lethality of DDR inhibitors with common oncogenic alterations such as mutations of TP53, RB1, ATM, amplifications of MYC, CCNE1 and others. The response to RS is normally limited by coordination of cell cycle, transcription and replication. Inhibition of WEE1 and PKMYT1 kinases, which prevent unscheduled mitosis entry, leads to fragility of under-replicated sites. Recent evidence also shows that inhibition of Cyclin-dependent kinases (CDKs), such as CDK4/6, CDK2, CDK8/19 and CDK12/13 can contribute to RS through disruption of DNA repair and replication control. Here, we review the main causes of RS in cancers as well as main therapeutic targets-ATR, CHK1, PARP and their inhibitors.
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Affiliation(s)
- Alvina I. Khamidullina
- Laboratory of Molecular Oncobiology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia; (A.I.K.); (Y.E.A.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia
| | - Yaroslav E. Abramenko
- Laboratory of Molecular Oncobiology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia; (A.I.K.); (Y.E.A.)
| | - Alexandra V. Bruter
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia
| | - Victor V. Tatarskiy
- Laboratory of Molecular Oncobiology, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia; (A.I.K.); (Y.E.A.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov Street, 119334 Moscow, Russia
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Mohammed OA, Alghamdi M, Alfaifi J, Alamri MMS, Al-Shahrani AM, Alharthi MH, Alshahrani AM, Alhalafi AH, Adam MIE, Bahashwan E, Jarallah AlQahtani AA, BinAfif WF, Abdel-Reheim MA, Abdel Mageed SS, Doghish AS. The emerging role of miRNAs in myocardial infarction: From molecular signatures to therapeutic targets. Pathol Res Pract 2024; 253:155087. [PMID: 38183820 DOI: 10.1016/j.prp.2023.155087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 12/28/2023] [Accepted: 12/30/2023] [Indexed: 01/08/2024]
Abstract
Globally, myocardial infarction (MI) and other cardiovascular illnesses have long been considered the top killers. Heart failure and mortality are the results of myocardial apoptosis, cardiomyocyte fibrosis, and cardiomyocyte hypertrophy, all of which are caused by MI. MicroRNAs (miRNAs) play a crucial regulatory function in the progression and advancement of heart disease following an MI. By consolidating the existing data on miRNAs, our aim is to gain a more comprehensive understanding of their role in the pathological progression of myocardial injury after MI and to identify potential crucial target pathways. Also included are the primary treatment modalities and their most recent developments. miRNAs have the ability to regulate both normal and pathological activity, including the key signaling pathways. As a result, they may exert medicinal benefits. This review presents a comprehensive analysis of the role of miRNAs in MI with a specific emphasis on their impact on the regeneration of cardiomyocytes and other forms of cell death, such as apoptosis, necrosis, and autophagy. Furthermore, the targets of pro- and anti-MI miRNAs are comparatively elucidated.
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Affiliation(s)
- Osama A Mohammed
- Department of Pharmacology, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia.
| | - Mushabab Alghamdi
- Department of Internal Medicine, Division of Rheumatology, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Jaber Alfaifi
- Department of Child Health, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Mohannad Mohammad S Alamri
- Department of Family and Community Medicine, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Abdullah M Al-Shahrani
- Department of Family and Community Medicine, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Muffarah Hamid Alharthi
- Department of Family and Community Medicine, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Abdullah M Alshahrani
- Department of Family and Community Medicine, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Abdullah Hassan Alhalafi
- Department of Family and Community Medicine, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Masoud I E Adam
- Department of Medical Education and Internal Medicine, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Emad Bahashwan
- Department of Internal Medicine, Division of Dermatology, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - AbdulElah Al Jarallah AlQahtani
- Department of Internal Medicine, Division of Dermatology, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Waad Fuad BinAfif
- Department of Internal Medicine, College of Medicine, University of Bisha, Bisha 61922, Saudi Arabia
| | - Mustafa Ahmed Abdel-Reheim
- Department of Pharmaceutical Sciences, College of Pharmacy, Shaqra University, Shaqra 11961, Saudi Arabia; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni Suef 62521, Egypt.
| | - Sherif S Abdel Mageed
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Ahmed S Doghish
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt; Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City 11231, Cairo, Egypt.
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Ranjan A, Thoenen EA, Kaida A, Wood S, Van Dyke T, Iwakuma T. Characterization of an Mtbp Hypomorphic Allele in a Diethylnitrosamine-Induced Liver Carcinogenesis Model. Cancers (Basel) 2023; 15:4596. [PMID: 37760565 PMCID: PMC10526184 DOI: 10.3390/cancers15184596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
MTBP is implicated in cell cycle progression, DNA replication, and cancer metastasis. However, the function of MTBP remains enigmatic and is dependent on cellular contexts and its cellular localization. To understand the in vivo physiological role of MTBP, it is important to generate Mtbp knockout mice. However, complete deletion of the Mtbp gene in mice results in early embryonic lethality, while its heterozygous deletion shows modest biological phenotypes, including enhanced cancer metastasis. To overcome this and better characterize the in vivo physiological function of MTBP, we, for the first time, generated mice that carry an Mtbp hypomorphic allele (MtbpH) in which Mtbp protein is expressed at approximately 30% of that in the wild-type allele. We treated wild-type, Mtbp+/-, and MtbpH/- mice with a liver carcinogen, diethylnitrosamine (DEN), and found that the MtbpH/- mice showed worse overall survival when compared to the wild-type mice. Consistent with previous reports using human liver cancer cells, mouse embryonic fibroblasts (MEFs) from the MtbpH/- mice showed an increase in the nuclear localization of p-Erk1/2 and migratory potential. Thus, MtbpH/- mice and cells from MtbpH/- mice are valuable to understand the in vivo physiological role of Mtbp and validate the diverse functions of MTBP that have been observed in human cells.
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Affiliation(s)
- Atul Ranjan
- Department of Pediatrics, Children’s Mercy Research Institute, Kansas City, MO 64108, USA
| | - Elizabeth A. Thoenen
- Department of Pediatrics, Children’s Mercy Research Institute, Kansas City, MO 64108, USA
| | - Atsushi Kaida
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Stephanie Wood
- Department of Pathology & Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | | | - Tomoo Iwakuma
- Department of Pediatrics, Children’s Mercy Research Institute, Kansas City, MO 64108, USA
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Kasprzak A. Prognostic Biomarkers of Cell Proliferation in Colorectal Cancer (CRC): From Immunohistochemistry to Molecular Biology Techniques. Cancers (Basel) 2023; 15:4570. [PMID: 37760539 PMCID: PMC10526446 DOI: 10.3390/cancers15184570] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/04/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023] Open
Abstract
Colorectal cancer (CRC) is one of the most common and severe malignancies worldwide. Recent advances in diagnostic methods allow for more accurate identification and detection of several molecular biomarkers associated with this cancer. Nonetheless, non-invasive and effective prognostic and predictive testing in CRC patients remains challenging. Classical prognostic genetic markers comprise mutations in several genes (e.g., APC, KRAS/BRAF, TGF-β, and TP53). Furthermore, CIN and MSI serve as chromosomal markers, while epigenetic markers include CIMP and many other candidates such as SERP, p14, p16, LINE-1, and RASSF1A. The number of proliferation-related long non-coding RNAs (e.g., SNHG1, SNHG6, MALAT-1, CRNDE) and microRNAs (e.g., miR-20a, miR-21, miR-143, miR-145, miR-181a/b) that could serve as potential CRC markers has also steadily increased in recent years. Among the immunohistochemical (IHC) proliferative markers, the prognostic value regarding the patients' overall survival (OS) or disease-free survival (DFS) has been confirmed for thymidylate synthase (TS), cyclin B1, cyclin D1, proliferating cell nuclear antigen (PCNA), and Ki-67. In most cases, the overexpression of these markers in tissues was related to worse OS and DFS. However, slowly proliferating cells should also be considered in CRC therapy (especially radiotherapy) as they could represent a reservoir from which cells are recruited to replenish the rapidly proliferating population in response to cell-damaging factors. Considering the above, the aim of this article is to review the most common proliferative markers assessed using various methods including IHC and selected molecular biology techniques (e.g., qRT-PCR, in situ hybridization, RNA/DNA sequencing, next-generation sequencing) as prognostic and predictive markers in CRC.
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Affiliation(s)
- Aldona Kasprzak
- Department of Histology and Embryology, University of Medical Sciences, Swiecicki Street 6, 60-781 Poznan, Poland
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Elsakka EGE, Abulsoud AI, El-Mahdy HA, Ismail A, Elballal MS, Mageed SSA, Khidr EG, Mohammed OA, Sarhan OM, Elkhawaga SY, El-Husseiny AA, Abdelmaksoud NM, El-Demerdash AA, Shahin RK, Midan HM, Elrebehy MA, Doghish AA, Doghish AS. miRNAs orchestration of cardiovascular diseases - Particular emphasis on diagnosis, and progression. Pathol Res Pract 2023; 248:154613. [PMID: 37327567 DOI: 10.1016/j.prp.2023.154613] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 06/18/2023]
Abstract
MicroRNAs (miRNAs; miRs) are small non-coding ribonucleic acids sequences vital in regulating gene expression. They are significant in many biological and pathological processes and are even detectable in various body fluids such as serum, plasma, and urine. Research has demonstrated that the irregularity of miRNA in multiplying cardiac cells is linked to developmental deformities in the heart's structure. It has also shown that miRNAs are crucial in diagnosing and progressing several cardiovascular diseases (CVDs). The review covers the function of miRNAs in the pathophysiology of CVD. Additionally, the review provides an overview of the potential role of miRNAs as disease-specific diagnostic and prognostic biomarkers for human CVD, as well as their biological implications in CVD.
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Affiliation(s)
- Elsayed G E Elsakka
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt
| | - Ahmed I Abulsoud
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt; Biochemistry Department, Faculty of Pharmacy, Heliopolis University, Cairo 11785, Egypt
| | - Hesham A El-Mahdy
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt.
| | - Ahmed Ismail
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt
| | - Mohammed S Elballal
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Sherif S Abdel Mageed
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Emad Gamil Khidr
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt
| | - Osama A Mohammed
- Department of Clinical Pharmacology, Faculty of Medicine, Bisha University, Bisha 61922, Saudi Arabia; Department of Clinical Pharmacology, Faculty of Medicine, Ain Shams University, Cairo 11566, Egypt
| | - Omnia M Sarhan
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Samy Y Elkhawaga
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt
| | - Ahmed A El-Husseiny
- Biochemistry and Molecular Biology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt; Department of Biochemistry, Faculty of Pharmacy, Egyptian Russian University, Badr City, 11829 Cairo, Egypt
| | | | - Aya A El-Demerdash
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Reem K Shahin
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Heba M Midan
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Mahmoud A Elrebehy
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt
| | - Ayman A Doghish
- Department of Cardiovascular & Thoracic Surgery, Ain-Shams University Hospital, Faculty of Medicine, Cairo, Egypt
| | - Ahmed S Doghish
- Department of Biochemistry, Faculty of Pharmacy, Badr University in Cairo (BUC), Badr City, Cairo 11829, Egypt; Faculty of Pharmacy (Boys), Al-Azhar University, Nasr City, 11231 Cairo, Egypt.
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Han F, Wang C, Cheng P, Liu T, Wang WS. Bone marrow mesenchymal stem cells derived exosomal miRNAs can modulate diabetic bone-fat imbalance. Front Endocrinol (Lausanne) 2023; 14:1149168. [PMID: 37124755 PMCID: PMC10145165 DOI: 10.3389/fendo.2023.1149168] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 03/09/2023] [Indexed: 05/02/2023] Open
Abstract
Background Diabetes mellitus is a chronic metabolic disease with systemic complications. Patient with diabetes have increased risks of bone fracture. Previous studies report that diabetes could affect bone metabolism, however, the underlying mechanism is still unclear. Methods We isolated exosomes secreted by bone marrow mesenchymal stem cells of normal and diabetic mice and test their effects on osteogenesis and adipogenesis. Then we screened the differential microRNAs by high-throughput sequencing and explored the function of key microRNA in vitro and in vivo. Results We find that lower bone mass and higher marrow fat accumulation, also called bone-fat imbalance, exists in diabetic mouse model. Exosomes secreted by normal bone marrow mesenchymal stem cells (BMSCs-Exos) enhanced osteogenesis and suppressed adipogenesis, while these effects were diminished in diabetic BMSCs-Exos. miR-221, as one of the highly expressed miRNAs within diabetic BMSCs-Exos, showed abilities of suppressing osteogenesis and promoting adipogenesis both in vitro and in vivo. Elevation of miR-221 level in normal BMSCs-Exos impairs the ability of regulating osteogenesis and adipogenesis. Intriguingly, using the aptamer delivery system, delivery normal BMSCs-Exos specifically to BMSCs increased bone mass, reduced marrow fat accumulation, and promoted bone regeneration in diabetic mice. Conclusion We demonstrate that BMSCs derived exosomal miR-221 is a key regulator of diabetic osteoporosis, which may represent a potential therapeutic target for diabetes-related skeletal disorders.
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Affiliation(s)
- Fei Han
- Medical College, Shihezi University, Shihezi, Xinjiang, China
- Department of Orthopaedics, The First Affiliated Hospital of the Medical College, Shihezi University, Shihezi, Xinjiang, China
| | - Chao Wang
- Medical College, Shihezi University, Shihezi, Xinjiang, China
- Department of Orthopaedics, The First Affiliated Hospital of the Medical College, Shihezi University, Shihezi, Xinjiang, China
| | - Peng Cheng
- Division of Geriatric Endocrinology, The First Affiliated Hospital, Nanjing Medical University, Nanjing, China
- *Correspondence: Peng Cheng, ; Ting Liu, ; Wei-Shan Wang,
| | - Ting Liu
- Department of Endocrinology, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, Hunan, China
- *Correspondence: Peng Cheng, ; Ting Liu, ; Wei-Shan Wang,
| | - Wei-Shan Wang
- Medical College, Shihezi University, Shihezi, Xinjiang, China
- Department of Orthopaedics, The First Affiliated Hospital of the Medical College, Shihezi University, Shihezi, Xinjiang, China
- *Correspondence: Peng Cheng, ; Ting Liu, ; Wei-Shan Wang,
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Dimerization of Firing Factors for Replication Origin Activation in Eukaryotes: A Crucial Process for Simultaneous Assembly of Bidirectional Replication Forks? BIOLOGY 2022; 11:biology11060928. [PMID: 35741449 PMCID: PMC9219616 DOI: 10.3390/biology11060928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Chromosomal DNA must be faithfully duplicated and segregated into two daughter cells when cells divide. DNA synthesis initiates from specific regions known as the origins of replication. When it starts, a pair of the replication fork is established, and each replication fork moves away from replication origins. In each replication fork, replicative helicase unwinds DNA from a double to a single strand. This implies that two sets of active helicase are generated from each replication origin. To make this possible, two sets of replicative helicases are loaded onto replication origins as inactive dimers first. When S-phase specific cyclin-dependent kinases, S-CDKs, are activated, the inactive helicase is converted into the active helicase with the aid of other factors called firing factors. Although two sets of firing factors seem to be required to activate two sets of helicase, it is largely unknown whether two sets of firing factors function simultaneously to establish bidirectional replication forks in a coordinated way. We introduce our current understanding of firing factor dimerization and discuss its potential contribution to bidirectional replication fork formation in this review. Abstract Controlling the activity of the heterohexameric Mcm2–7 replicative helicase is crucial for regulation of replication origin activity in eukaryotes. Because bidirectional replication forks are generated from every replication origin, when origins are licensed for replication in the first step of DNA replication, two inactive Mcm2–7 heterohexiameric complexes are loaded around double stranded DNA as a head-to-head double hexamer. The helicases are subsequently activated via a ‘firing’ reaction, in which the Mcm2–7 double hexamer is converted into two active helicase units, the CMG complex, by firing factors. Dimerization of firing factors may contribute to this process by allowing simultaneous activation of two sets of helicases and thus efficient assembly of bidirectional replication forks. An example of this is dimerization of the firing factor Sld3/Treslin/Ticrr via its binding partner, Sld7/MTBP. In organisms in which no Sld7 ortholog has been identified, such as the fission yeast Schizosaccharomyces pombe, Sld3 itself has a dimerization domain, and it has been suggested that this self-interaction is crucial for the firing reaction in this organism. Dimerization induces a conformational change in Sdl3 that appears to be critical for the firing reaction. Moreover, Mcm10 also seems to be regulated by self-interaction in yeasts. Although it is not yet clear to what extent dimerization of firing factors contributes to the firing reaction in eukaryotes, we discuss the possible roles of firing factor dimerization in simultaneous helicase activation.
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Grieb BC, Eischen CM. MTBP and MYC: A Dynamic Duo in Proliferation, Cancer, and Aging. BIOLOGY 2022; 11:biology11060881. [PMID: 35741402 PMCID: PMC9219613 DOI: 10.3390/biology11060881] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/29/2022] [Accepted: 06/02/2022] [Indexed: 12/21/2022]
Abstract
The oncogenic transcription factor c-MYC (MYC) is highly conserved across species and is frequently overexpressed or dysregulated in human cancers. MYC regulates a wide range of critical cellular and oncogenic activities including proliferation, metabolism, metastasis, apoptosis, and differentiation by transcriptionally activating or repressing the expression of a large number of genes. This activity of MYC is not carried out in isolation, instead relying on its association with a myriad of protein cofactors. We determined that MDM Two Binding Protein (MTBP) indirectly binds MYC and is a novel MYC transcriptional cofactor. MTBP promotes MYC-mediated transcriptional activity, proliferation, and cellular transformation by binding in a protein complex with MYC at MYC-bound promoters. This discovery provided critical context for data linking MTBP to aging as well as a rapidly expanding body of evidence demonstrating MTBP is overexpressed in many human malignancies, is often linked to poor patient outcomes, and is necessary for cancer cell survival. As such, MTBP represents a novel and potentially broad reaching oncologic drug target, particularly when MYC is dysregulated. Here we have reviewed the discovery of MTBP and the initial controversy with its function as well as its associations with proliferation, MYC, DNA replication, aging, and human cancer.
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Affiliation(s)
- Brian C. Grieb
- Vanderbilt-Ingram Cancer Center, Division of Hematology/Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
- Department of Cell & Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Christine M. Eischen
- Department of Cancer Biology and the Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
- Correspondence:
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10
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Gillespie PJ, Blow JJ. DDK: The Outsourced Kinase of Chromosome Maintenance. BIOLOGY 2022; 11:biology11060877. [PMID: 35741398 PMCID: PMC9220011 DOI: 10.3390/biology11060877] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/31/2022] [Accepted: 06/02/2022] [Indexed: 11/16/2022]
Abstract
The maintenance of genomic stability during the mitotic cell-cycle not only demands that the DNA is duplicated and repaired with high fidelity, but that following DNA replication the chromatin composition is perpetuated and that the duplicated chromatids remain tethered until their anaphase segregation. The coordination of these processes during S phase is achieved by both cyclin-dependent kinase, CDK, and Dbf4-dependent kinase, DDK. CDK orchestrates the activation of DDK at the G1-to-S transition, acting as the ‘global’ regulator of S phase and cell-cycle progression, whilst ‘local’ control of the initiation of DNA replication and repair and their coordination with the re-formation of local chromatin environments and the establishment of chromatid cohesion are delegated to DDK. Here, we discuss the regulation and the multiple roles of DDK in ensuring chromosome maintenance. Regulation of replication initiation by DDK has long been known to involve phosphorylation of MCM2-7 subunits, but more recent results have indicated that Treslin:MTBP might also be important substrates. Molecular mechanisms by which DDK regulates replisome stability and replicated chromatid cohesion are less well understood, though important new insights have been reported recently. We discuss how the ‘outsourcing’ of activities required for chromosome maintenance to DDK allows CDK to maintain outright control of S phase progression and the cell-cycle phase transitions whilst permitting ongoing chromatin replication and cohesion establishment to be completed and achieved faithfully.
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11
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Zaffar E, Ferreira P, Sanchez-Pulido L, Boos D. The Role of MTBP as a Replication Origin Firing Factor. BIOLOGY 2022; 11:biology11060827. [PMID: 35741348 PMCID: PMC9219753 DOI: 10.3390/biology11060827] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/20/2022] [Accepted: 05/22/2022] [Indexed: 12/12/2022]
Abstract
The initiation step of replication at replication origins determines when and where in the genome replication machines, replisomes, are generated. Tight control of replication initiation helps facilitate the two main tasks of genome replication, to duplicate the genome accurately and exactly once each cell division cycle. The regulation of replication initiation must ensure that initiation occurs during the S phase specifically, that no origin fires more than once per cell cycle, that enough origins fire to avoid non-replicated gaps, and that the right origins fire at the right time but only in favorable circumstances. Despite its importance for genetic homeostasis only the main molecular processes of eukaryotic replication initiation and its cellular regulation are understood. The MTBP protein (Mdm2-binding protein) is so far the last core replication initiation factor identified in metazoan cells. MTBP is the orthologue of yeast Sld7. It is essential for origin firing, the maturation of pre-replicative complexes (pre-RCs) into replisomes, and is emerging as a regulation focus targeted by kinases and by regulated degradation. We present recent insight into the structure and cellular function of the MTBP protein in light of recent structural and biochemical studies revealing critical molecular details of the eukaryotic origin firing reaction. How the roles of MTBP in replication and other cellular processes are mutually connected and are related to MTBP's contribution to tumorigenesis remains largely unclear.
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Affiliation(s)
- Eman Zaffar
- Molecular Genetics II, Centre for Medical Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany; (E.Z.); (P.F.)
| | - Pedro Ferreira
- Molecular Genetics II, Centre for Medical Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany; (E.Z.); (P.F.)
| | - Luis Sanchez-Pulido
- Medical Research Council Human Genetics Unit, IGC, University of Edinburgh, Edinburgh EH9 3JR, UK;
| | - Dominik Boos
- Molecular Genetics II, Centre for Medical Biotechnology, University of Duisburg-Essen, 45141 Essen, Germany; (E.Z.); (P.F.)
- Correspondence: ; Tel.: +49-201-183-4132
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12
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The Mediator kinase module: an interface between cell signaling and transcription. Trends Biochem Sci 2022; 47:314-327. [DOI: 10.1016/j.tibs.2022.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 01/11/2022] [Accepted: 01/17/2022] [Indexed: 12/14/2022]
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13
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Ferreira P, Sanchez-Pulido L, Marko A, Ponting CP, Boos D. Refining the domain architecture model of the replication origin firing factor Treslin/TICRR. Life Sci Alliance 2022; 5:5/5/e202101088. [PMID: 35091422 PMCID: PMC8807876 DOI: 10.26508/lsa.202101088] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 11/24/2022] Open
Abstract
Faithful genome duplication requires appropriately controlled replication origin firing. The metazoan origin firing regulation hub Treslin/TICRR and its yeast orthologue Sld3 share the Sld3-Treslin domain and the adjacent TopBP1/Dpb11 interaction domain. We report a revised domain architecture model of Treslin/TICRR. Protein sequence analyses uncovered a conserved Ku70-homologous β-barrel fold in the Treslin/TICRR middle domain (M domain) and in Sld3. Thus, the Sld3-homologous Treslin/TICRR core comprises its three central domains, M domain, Sld3-Treslin domain, and TopBP1/Dpb11 interaction domain, flanked by non-conserved terminal domains, the CIT (conserved in Treslins) and the C terminus. The CIT includes a von Willebrand factor type A domain. Unexpectedly, MTBP, Treslin/TICRR, and Ku70/80 share the same N-terminal domain architecture, von Willebrand factor type A and Ku70-like β-barrels, suggesting a common ancestry. Binding experiments using mutants and the Sld3-Sld7 dimer structure suggest that the Treslin/Sld3 and MTBP/Sld7 β-barrels engage in homotypic interactions, reminiscent of Ku70-Ku80 dimerization. Cells expressing Treslin/TICRR domain mutants indicate that all Sld3-core domains and the non-conserved terminal domains fulfil important functions during origin firing in human cells. Thus, metazoa-specific and widely conserved molecular processes cooperate during metazoan origin firing.
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Affiliation(s)
- Pedro Ferreira
- Molecular Genetics II, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Luis Sanchez-Pulido
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Anika Marko
- Molecular Genetics II, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Chris P Ponting
- Medical Research Council Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Dominik Boos
- Molecular Genetics II, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany
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14
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Dou P, Tan G, Fan Z, Xiao J, Shi C, Lin Z, Duan J. MicroRNA-9 facilitates hypoxia-induced injury and apoptosis in H9c2 cells via targeting CDK8. J Biosci 2021. [DOI: 10.1007/s12038-020-00126-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Wittig KA, Sansam CG, Noble TD, Goins D, Sansam CL. The CRL4DTL E3 ligase induces degradation of the DNA replication initiation factor TICRR/TRESLIN specifically during S phase. Nucleic Acids Res 2021; 49:10507-10523. [PMID: 34534348 PMCID: PMC8501952 DOI: 10.1093/nar/gkab805] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 08/26/2021] [Accepted: 09/13/2021] [Indexed: 01/02/2023] Open
Abstract
A DNA replication program, which ensures that the genome is accurately and wholly replicated, is established during G1, before the onset of S phase. In G1, replication origins are licensed, and upon S phase entry, a subset of these will form active replisomes. Tight regulation of the number of active replisomes is crucial to prevent replication stress-induced DNA damage. TICRR/TRESLIN is essential for DNA replication initiation, and the level of TICRR and its phosphorylation determine the number of origins that initiate during S phase. However, the mechanisms regulating TICRR protein levels are unknown. Therefore, we set out to define the TICRR/TRESLIN protein dynamics throughout the cell cycle. Here, we show that TICRR levels are high during G1 and dramatically decrease as cells enter S phase and begin DNA replication. We show that degradation of TICRR occurs specifically during S phase and depends on ubiquitin ligases and proteasomal degradation. Using two targeted siRNA screens, we identify CRL4DTL as a cullin complex necessary for TICRR degradation. We propose that this mechanism moderates the level of TICRR protein available for replication initiation, ensuring the proper number of active origins as cells progress through S phase.
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Affiliation(s)
- Kimberlie A Wittig
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Courtney G Sansam
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Tyler D Noble
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Duane Goins
- Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Christopher L Sansam
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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16
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Lloyd R, Urban V, Muñoz-Martínez F, Ayestaran I, Thomas J, de Renty C, O’Connor M, Forment J, Galanty Y, Jackson S. Loss of Cyclin C or CDK8 provides ATR inhibitor resistance by suppressing transcription-associated replication stress. Nucleic Acids Res 2021; 49:8665-8683. [PMID: 34329458 PMCID: PMC8421211 DOI: 10.1093/nar/gkab628] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 07/04/2021] [Accepted: 07/09/2021] [Indexed: 02/07/2023] Open
Abstract
The protein kinase ATR plays pivotal roles in DNA repair, cell cycle checkpoint engagement and DNA replication. Consequently, ATR inhibitors (ATRi) are in clinical development for the treatment of cancers, including tumours harbouring mutations in the related kinase ATM. However, it still remains unclear which functions and pathways dominate long-term ATRi efficacy, and how these vary between clinically relevant genetic backgrounds. Elucidating common and genetic-background specific mechanisms of ATRi efficacy could therefore assist in patient stratification and pre-empting drug resistance. Here, we use CRISPR-Cas9 genome-wide screening in ATM-deficient and proficient mouse embryonic stem cells to interrogate cell fitness following treatment with the ATRi, ceralasertib. We identify factors that enhance or suppress ATRi efficacy, with a subset of these requiring intact ATM signalling. Strikingly, two of the strongest resistance-gene hits in both ATM-proficient and ATM-deficient cells encode Cyclin C and CDK8: members of the CDK8 kinase module for the RNA polymerase II mediator complex. We show that Cyclin C/CDK8 loss reduces S-phase DNA:RNA hybrid formation, transcription-replication stress, and ultimately micronuclei formation induced by ATRi. Overall, our work identifies novel biomarkers of ATRi efficacy in ATM-proficient and ATM-deficient cells, and highlights transcription-associated replication stress as a predominant driver of ATRi-induced cell death.
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Affiliation(s)
- Rebecca L Lloyd
- Wellcome/Cancer Research UK Gurdon Institute, and Department of Biochemistry, University of Cambridge, UK
| | - Vaclav Urban
- Bioscience, Oncology R&D, AstraZeneca, Cambridge, UK
| | - Francisco Muñoz-Martínez
- Wellcome/Cancer Research UK Gurdon Institute, and Department of Biochemistry, University of Cambridge, UK
| | - Iñigo Ayestaran
- Wellcome/Cancer Research UK Gurdon Institute, and Department of Biochemistry, University of Cambridge, UK
| | - John C Thomas
- Wellcome/Cancer Research UK Gurdon Institute, and Department of Biochemistry, University of Cambridge, UK
| | | | | | | | - Yaron Galanty
- Wellcome/Cancer Research UK Gurdon Institute, and Department of Biochemistry, University of Cambridge, UK
| | - Stephen P Jackson
- Wellcome/Cancer Research UK Gurdon Institute, and Department of Biochemistry, University of Cambridge, UK
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17
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Kumagai A, Dunphy WG. Binding of the Treslin-MTBP Complex to Specific Regions of the Human Genome Promotes the Initiation of DNA Replication. Cell Rep 2021; 32:108178. [PMID: 32966791 PMCID: PMC7523632 DOI: 10.1016/j.celrep.2020.108178] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/12/2020] [Accepted: 08/31/2020] [Indexed: 12/16/2022] Open
Abstract
The processes that control where higher eukaryotic cells initiate DNA replication throughout the genome are not understood clearly. In metazoans, the Treslin-MTBP complex mediates critical final steps in formation of the activated replicative helicase prior to initiation of replication. Here, we map the genome-wide distribution of the MTBP subunit of this complex in human cells. Our results indicate that MTBP binds to at least 30,000 sites in the genome. A majority of these sites reside in regions of open chromatin that contain transcriptional-regulatory elements (e.g., promoters, enhancers, and super-enhancers), which are known to be preferred areas for initiation of replication. Furthermore, many binding sites encompass two genomic features: a nucleosome-free DNA sequence (e.g., G-quadruplex DNA or AP-1 motif) and a nucleosome bearing histone marks characteristic of open chromatin, such as H3K4me2. Taken together, these findings indicate that Treslin-MTBP associates coordinately with multiple genomic signals to promote initiation of replication. Kumagai and Dunphy show that Treslin-MTBP, activator of the replicative helicase, binds to at least 30,000 sites in the human genome. Many sites contain a nucleosome with active chromatin marks and nucleosome-free DNA (G-quadruplex or AP-1 site). Thus, Treslin-MTBP associates with multiple genomic elements to promote initiation of DNA replication.
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Affiliation(s)
- Akiko Kumagai
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - William G Dunphy
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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18
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Dissection of two routes to naïve pluripotency using different kinase inhibitors. Nat Commun 2021; 12:1863. [PMID: 33767186 PMCID: PMC7994667 DOI: 10.1038/s41467-021-22181-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 03/04/2021] [Indexed: 01/31/2023] Open
Abstract
Embryonic stem cells (ESCs) can be maintained in the naïve state through inhibition of Mek1/2 and Gsk3 (2i). A relevant effect of 2i is the inhibition of Cdk8/19, which are negative regulators of the Mediator complex, responsible for the activity of enhancers. Inhibition of Cdk8/19 (Cdk8/19i) stimulates enhancers and, similar to 2i, stabilizes ESCs in the naïve state. Here, we use mass spectrometry to describe the molecular events (phosphoproteome, proteome, and metabolome) triggered by 2i and Cdk8/19i on ESCs. Our data reveal widespread commonalities between these two treatments, suggesting overlapping processes. We find that post-transcriptional de-repression by both 2i and Cdk8/19i might support the mitochondrial capacity of naive cells. However, proteome reprogramming in each treatment is achieved by different mechanisms. Cdk8/19i acts directly on the transcriptional machinery, activating key identity genes to promote the naïve program. In contrast, 2i stabilizes the naïve circuitry through, in part, de-phosphorylation of downstream transcriptional effectors.
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19
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MTBP phosphorylation controls DNA replication origin firing. Sci Rep 2021; 11:4242. [PMID: 33608586 PMCID: PMC7895959 DOI: 10.1038/s41598-021-83287-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 01/28/2021] [Indexed: 12/24/2022] Open
Abstract
Faithful genome duplication requires regulation of origin firing to determine loci, timing and efficiency of replisome generation. Established kinase targets for eukaryotic origin firing regulation are the Mcm2-7 helicase, Sld3/Treslin/TICRR and Sld2/RecQL4. We report that metazoan Sld7, MTBP (Mdm2 binding protein), is targeted by at least three kinase pathways. MTBP was phosphorylated at CDK consensus sites by cell cycle cyclin-dependent kinases (CDK) and Cdk8/19-cyclin C. Phospho-mimetic MTBP CDK site mutants, but not non-phosphorylatable mutants, promoted origin firing in human cells. MTBP was also phosphorylated at DNA damage checkpoint kinase consensus sites. Phospho-mimetic mutations at these sites inhibited MTBP’s origin firing capability. Whilst expressing a non-phospho MTBP mutant was insufficient to relieve the suppression of origin firing upon DNA damage, the mutant induced a genome-wide increase of origin firing in unperturbed cells. Our work establishes MTBP as a regulation platform of metazoan origin firing.
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20
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Schmit M, Bielinsky AK. Congenital Diseases of DNA Replication: Clinical Phenotypes and Molecular Mechanisms. Int J Mol Sci 2021; 22:E911. [PMID: 33477564 PMCID: PMC7831139 DOI: 10.3390/ijms22020911] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 12/19/2022] Open
Abstract
Deoxyribonucleic acid (DNA) replication can be divided into three major steps: initiation, elongation and termination. Each time a human cell divides, these steps must be reiteratively carried out. Disruption of DNA replication can lead to genomic instability, with the accumulation of point mutations or larger chromosomal anomalies such as rearrangements. While cancer is the most common class of disease associated with genomic instability, several congenital diseases with dysfunctional DNA replication give rise to similar DNA alterations. In this review, we discuss all congenital diseases that arise from pathogenic variants in essential replication genes across the spectrum of aberrant replisome assembly, origin activation and DNA synthesis. For each of these conditions, we describe their clinical phenotypes as well as molecular studies aimed at determining the functional mechanisms of disease, including the assessment of genomic stability. By comparing and contrasting these diseases, we hope to illuminate how the disruption of DNA replication at distinct steps affects human health in a surprisingly cell-type-specific manner.
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Affiliation(s)
| | - Anja-Katrin Bielinsky
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA;
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21
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Gaggioli V, Kieninger MR, Klucnika A, Butler R, Zegerman P. Identification of the critical replication targets of CDK reveals direct regulation of replication initiation factors by the embryo polarity machinery in C. elegans. PLoS Genet 2020; 16:e1008948. [PMID: 33320862 PMCID: PMC7771872 DOI: 10.1371/journal.pgen.1008948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 12/29/2020] [Accepted: 11/02/2020] [Indexed: 12/26/2022] Open
Abstract
During metazoan development, the cell cycle is remodelled to coordinate proliferation with differentiation. Developmental cues cause dramatic changes in the number and timing of replication initiation events, but the mechanisms and physiological importance of such changes are poorly understood. Cyclin-dependent kinases (CDKs) are important for regulating S-phase length in many metazoa, and here we show in the nematode Caenorhabditis elegans that an essential function of CDKs during early embryogenesis is to regulate the interactions between three replication initiation factors SLD-3, SLD-2 and MUS-101 (Dpb11/TopBP1). Mutations that bypass the requirement for CDKs to generate interactions between these factors is partly sufficient for viability in the absence of Cyclin E, demonstrating that this is a critical embryonic function of this Cyclin. Both SLD-2 and SLD-3 are asymmetrically localised in the early embryo and the levels of these proteins inversely correlate with S-phase length. We also show that SLD-2 asymmetry is determined by direct interaction with the polarity protein PKC-3. This study explains an essential function of CDKs for replication initiation in a metazoan and provides the first direct molecular mechanism through which polarization of the embryo is coordinated with DNA replication initiation factors. How and when a cell divides changes as the cell assumes different fates. How these changes in cell division are brought about are poorly understood, but are critical to ensure that cells do not over-proliferate leading to cancer. The nematode C. elegans is an excellent system to study the role of cell cycle changes during animal development. Here we show that two factors SLD-2 and SLD-3 are critical to control the decision to begin genome duplication. We show that these factors are differently distributed to different cell lineages in the early embryo, which may be a key event in determining the cell cycle rate in these cells. For the first time we show that, PKC-3, a key component of the machinery that determines the front (anterior) from the back (posterior) of the embryo directly controls SLD-2 distribution, which might explain how the polarisation of the embryo causes changes in the proliferation of different cell lineages. As PKC-3 is frequently mutated in human cancers, how this factor controls cell proliferation may be important to understand tumour progression.
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Affiliation(s)
- Vincent Gaggioli
- Wellcome Trust/Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Cambridge, United Kingdom
| | - Manuela R. Kieninger
- Wellcome Trust/Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Cambridge, United Kingdom
| | - Anna Klucnika
- Wellcome Trust/Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Cambridge, United Kingdom
- Department of Genetics, University of Cambridge, United Kingdom
| | - Richard Butler
- Wellcome Trust/Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Cambridge, United Kingdom
| | - Philip Zegerman
- Wellcome Trust/Cancer Research UK Gurdon Institute, The Henry Wellcome Building of Cancer and Developmental Biology, University of Cambridge, Cambridge, United Kingdom
- Department of Biochemistry, University of Cambridge, United Kingdom
- * E-mail:
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22
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Bowden TJ, Kraev I, Lange S. Extracellular vesicles and post-translational protein deimination signatures in haemolymph of the American lobster (Homarus americanus). FISH & SHELLFISH IMMUNOLOGY 2020; 106:79-102. [PMID: 32731012 DOI: 10.1016/j.fsi.2020.06.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/21/2020] [Accepted: 06/27/2020] [Indexed: 06/11/2023]
Abstract
The American lobster (Homarus americanus) is a commercially important crustacean with an unusual long life span up to 100 years and a comparative animal model of longevity. Therefore, research into its immune system and physiology is of considerable importance both for industry and comparative immunology studies. Peptidylarginine deiminases (PADs) are a phylogenetically conserved enzyme family that catalyses post-translational protein deimination via the conversion of arginine to citrulline. This can lead to structural and functional protein changes, sometimes contributing to protein moonlighting, in health and disease. PADs also regulate the cellular release of extracellular vesicles (EVs), which is an important part of cellular communication, both in normal physiology and in immune responses. Hitherto, studies on EVs in Crustacea are limited and neither PADs nor associated protein deimination have been studied in a Crustacean species. The current study assessed EV and deimination signatures in haemolymph of the American lobster. Lobster EVs were found to be a poly-dispersed population in the 10-500 nm size range, with the majority of smaller EVs, which fell within 22-115 nm. In lobster haemolymph, 9 key immune and metabolic proteins were identified to be post-translationally deiminated, while further 41 deiminated protein hits were identified when searching against a Crustacean database. KEGG (Kyoto encyclopedia of genes and genomes) and GO (gene ontology) enrichment analysis of these deiminated proteins revealed KEGG and GO pathways relating to a number of immune, including anti-pathogenic (viral, bacterial, fungal) and host-pathogen interactions, as well as metabolic pathways, regulation of vesicle and exosome release, mitochondrial function, ATP generation, gene regulation, telomerase homeostasis and developmental processes. The characterisation of EVs, and post-translational deimination signatures, reported in lobster in the current study, and the first time in Crustacea, provides insights into protein moonlighting functions of both species-specific and phylogenetically conserved proteins and EV-mediated communication in this long-lived crustacean. The current study furthermore lays foundation for novel biomarker discovery for lobster aquaculture.
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Affiliation(s)
- Timothy J Bowden
- Aquaculture Research Institute, School of Food & Agriculture, University of Maine, Orono, ME, USA.
| | - Igor Kraev
- Electron Microscopy Suite, Faculty of Science,Technology, Engineering and Mathematics, Open University, Milton Keynes, MK7 6AA, UK.
| | - Sigrun Lange
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, University of Westminster, London, W1W 6UW, UK.
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23
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Chen B, Wen P, Hu G, Gao Y, Qi X, Zhu K, Chen S, Wu L, Xu A, Zhao G. Antagonizing CDK8 Sensitizes Colorectal Cancer to Radiation Through Potentiating the Transcription of e2f1 Target Gene apaf1. Front Cell Dev Biol 2020; 8:408. [PMID: 32596239 PMCID: PMC7304162 DOI: 10.3389/fcell.2020.00408] [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: 03/10/2020] [Accepted: 05/04/2020] [Indexed: 12/12/2022] Open
Abstract
Radiotherapy is an essential curative treatment modality for colorectal cancer. Apoptosis is the major mechanism of IR-induced cell death and aberrant apoptotic signaling results in radioresistance, which is a hallmark of most, perhaps all, types of human cancers. Potentiating the induction of apoptosis is an emerging strategy for cancer radiotherapy. Here, we determined that targeting CDK8 selectively radiosensitized colorectal cancer through the mitochondria-dependent intrinsic apoptotic signaling, which was mediated through the induction of the transcription of apaf1 that was e2f1- and not p53-dependent. Importantly, the enhanced transcriptional activity of e2f1 was dependent on the kinase activity of CDK8 itself and not on the assembling of the mediator complex. In addition, clinical inhibitor, and in vivo studies confirmed the radiosensitizing effect of CDK8. Our results provide a new targeting strategy to improve the radiotherapy of CRC.
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Affiliation(s)
- Bin Chen
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,University of Science and Technology of China, Hefei, China
| | - Pengbo Wen
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,University of Science and Technology of China, Hefei, China
| | - Guanshuo Hu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,University of Science and Technology of China, Hefei, China
| | - Yang Gao
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,University of Science and Technology of China, Hefei, China
| | - Xiaojing Qi
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,University of Science and Technology of China, Hefei, China
| | - Kaili Zhu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.,University of Science and Technology of China, Hefei, China
| | - Shaopeng Chen
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Lijun Wu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - An Xu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Guoping Zhao
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Anhui Province Key Laboratory of Environmental Toxicology and Pollution Control Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
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24
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Martínez-Alonso D, Malumbres M. Mammalian cell cycle cyclins. Semin Cell Dev Biol 2020; 107:28-35. [PMID: 32334991 DOI: 10.1016/j.semcdb.2020.03.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 03/27/2020] [Accepted: 03/31/2020] [Indexed: 12/23/2022]
Abstract
Proper progression throughout the cell division cycle depends on the expression level of a family of proteins known as cyclins, and the subsequent activation of cyclin-dependent kinases (Cdks). Among the numerous members of the mammalian cyclin family, only a few of them, cyclins A, B, C, D and E, are known to display critical roles in the cell cycle. These functions will be reviewed here with a special focus on their relevance in different cell types in vivo and their implications in human disease.
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Affiliation(s)
- Diego Martínez-Alonso
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO) Madrid, Spain.
| | - Marcos Malumbres
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO) Madrid, Spain.
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25
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Hsieh YYP, Makrantoni V, Robertson D, Marston AL, Murray AW. Evolutionary repair: Changes in multiple functional modules allow meiotic cohesin to support mitosis. PLoS Biol 2020; 18:e3000635. [PMID: 32155147 PMCID: PMC7138332 DOI: 10.1371/journal.pbio.3000635] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 04/07/2020] [Accepted: 02/21/2020] [Indexed: 12/12/2022] Open
Abstract
The role of proteins often changes during evolution, but we do not know how cells adapt when a protein is asked to participate in a different biological function. We forced the budding yeast, Saccharomyces cerevisiae, to use the meiosis-specific kleisin, recombination 8 (Rec8), during the mitotic cell cycle, instead of its paralog, Scc1. This perturbation impairs sister chromosome linkage, advances the timing of genome replication, and reduces reproductive fitness by 45%. We evolved 15 parallel populations for 1,750 generations, substantially increasing their fitness, and analyzed the genotypes and phenotypes of the evolved cells. Only one population contained a mutation in Rec8, but many populations had mutations in the transcriptional mediator complex, cohesin-related genes, and cell cycle regulators that induce S phase. These mutations improve sister chromosome cohesion and delay genome replication in Rec8-expressing cells. We conclude that changes in known and novel partners allow cells to use an existing protein to participate in new biological functions.
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Affiliation(s)
- Yu-Ying Phoebe Hsieh
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Vasso Makrantoni
- The Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Daniel Robertson
- The Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Adèle L. Marston
- The Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew W. Murray
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
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26
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Tanaka S. An efficient method for the isolation of interaction-null/impaired mutants using the yeast two-hybrid technique. Genes Cells 2019; 24:781-788. [PMID: 31599053 DOI: 10.1111/gtc.12724] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/24/2019] [Accepted: 10/05/2019] [Indexed: 01/15/2023]
Abstract
Protein-protein interactions are one of the most basic and critical processes underlying biological functions. Thus, identification of the interacting proteins of a protein of interest and further elucidation of the roles of the interactions is critical for understanding the related biological processes. The yeast two-hybrid (Y2H) method is a popular approach for identifying protein-protein interactions. Once interacting proteins are identified, a comparison of the phenotypes of mutants lacking the specific protein-protein interaction with those of the wild-type strain is a powerful tool for uncovering the former interactions' biological significance. However, isolation of such interaction-defective mutants is often laborious. Here, I describe a novel and efficient approach for isolating such mutants that uses the Y2H technique with a modified Y2H vector, and provide an example of how this approach can be used to screen interaction-null/impaired mutants. Because the strategy is simple and the modification of a pre-existing Y2H vector is sufficient for the screening purpose, the same strategy can be applied to any existing two-hybrid system.
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Affiliation(s)
- Seiji Tanaka
- School of Environmental Science and Engineering, Kochi University of Technology, Kami, Japan
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27
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Origin Firing Regulations to Control Genome Replication Timing. Genes (Basel) 2019; 10:genes10030199. [PMID: 30845782 PMCID: PMC6470937 DOI: 10.3390/genes10030199] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/25/2019] [Accepted: 02/28/2019] [Indexed: 12/19/2022] Open
Abstract
Complete genome duplication is essential for genetic homeostasis over successive cell generations. Higher eukaryotes possess a complex genome replication program that involves replicating the genome in units of individual chromatin domains with a reproducible order or timing. Two types of replication origin firing regulations ensure complete and well-timed domain-wise genome replication: (1) the timing of origin firing within a domain must be determined and (2) enough origins must fire with appropriate positioning in a short time window to avoid inter-origin gaps too large to be fully copied. Fundamental principles of eukaryotic origin firing are known. We here discuss advances in understanding the regulation of origin firing to control firing time. Work with yeasts suggests that eukaryotes utilise distinct molecular pathways to determine firing time of distinct sets of origins, depending on the specific requirements of the genomic regions to be replicated. Although the exact nature of the timing control processes varies between eukaryotes, conserved aspects exist: (1) the first step of origin firing, pre-initiation complex (pre-IC formation), is the regulated step, (2) many regulation pathways control the firing kinase Dbf4-dependent kinase, (3) Rif1 is a conserved mediator of late origin firing and (4) competition between origins for limiting firing factors contributes to firing timing. Characterization of the molecular timing control pathways will enable us to manipulate them to address the biological role of replication timing, for example, in cell differentiation and genome instability.
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