1
|
Kim J, Park EA, Shin MY, Park SJ. Functional Differentiation of Cyclins and Cyclin-Dependent Kinases in Giardia lamblia. Microbiol Spectr 2023; 11:e0491922. [PMID: 36877015 PMCID: PMC10100927 DOI: 10.1128/spectrum.04919-22] [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: 11/30/2022] [Accepted: 02/05/2023] [Indexed: 03/07/2023] Open
Abstract
Cyclin-dependent kinases (CDKs) are serine/threonine kinases that control the eukaryotic cell cycle. Limited information is available on Giardia lamblia CDKs (GlCDKs), GlCDK1 and GlCDK2. After treatment with the CDK inhibitor flavopiridol-HCl (FH), division of Giardia trophozoites was transiently arrested at the G1/S phase and finally at the G2/M phase. The percentage of cells arrested during prophase or cytokinesis increased, whereas DNA synthesis was not affected by FH treatment. Morpholino-mediated depletion of GlCDK1 caused arrest at the G2/M phase, while GlCDK2 depletion resulted in an increase in the number of cells arrested at the G1/S phase and cells defective in mitosis and cytokinesis. Coimmunoprecipitation experiments with GlCDKs and the nine putative G. lamblia cyclins (Glcyclins) identified Glcyclins 3977/14488/17505 and 22394/6584 as cognate partners of GlCDK1 and GlCDK2, respectively. Morpholino-based knockdown of Glcyclin 3977 or 22394/6584 arrested cells in the G2/M phase or G1/S phase, respectively. Interestingly, GlCDK1- and Glcyclin 3977-depleted Giardia showed significant flagellar extension. Altogether, our results suggest that GlCDK1/Glcyclin 3977 plays an important role in the later stages of cell cycle control and in flagellar biogenesis. In contrast, GlCDK2 along with Glcyclin 22394 and 6584 functions from the early stages of the Giardia cell cycle. IMPORTANCE Giardia lamblia CDKs (GlCDKs) and their cognate cyclins have not yet been studied. In this study, the functional roles of GlCDK1 and GlCDK2 were distinguished using morpholino-mediated knockdown and coimmunoprecipitation. GlCDK1 with Glcyclin 3977 plays a role in flagellum formation as well as cell cycle control of G. lamblia, whereas GlCDK2 with Glcyclin 22394/6584 is involved in cell cycle control.
Collapse
Affiliation(s)
- Juri Kim
- Department of Tropical Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Eun-Ah Park
- Department of Tropical Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Mee Young Shin
- Department of Tropical Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Soon-Jung Park
- Department of Tropical Medicine, Yonsei University College of Medicine, Seoul, South Korea
| |
Collapse
|
2
|
Defining the molecular underpinnings controlling cardiomyocyte proliferation. Clin Sci (Lond) 2022; 136:911-934. [PMID: 35723259 DOI: 10.1042/cs20211180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 05/27/2022] [Accepted: 05/31/2022] [Indexed: 12/11/2022]
Abstract
Shortly after birth, mammalian cardiomyocytes (CM) exit the cell cycle and cease to proliferate. The inability of adult CM to replicate renders the heart particularly vulnerable to injury. Restoration of CM proliferation would be an attractive clinical target for regenerative therapies that can preserve contractile function and thus prevent the development of heart failure. Our review focuses on recent progress in understanding the tight regulation of signaling pathways and their downstream molecular mechanisms that underly the inability of CM to proliferate in vivo. In this review, we describe the temporal expression of cell cycle activators e.g., cyclin/Cdk complexes and their inhibitors including p16, p21, p27 and members of the retinoblastoma gene family during gestation and postnatal life. The differential impact of members of the E2f transcription factor family and microRNAs on the regulation of positive and negative cell cycle factors is discussed. This review also highlights seminal studies that identified the coordination of signaling mechanisms that can potently activate CM cell cycle re-entry including the Wnt/Ctnnb1, Hippo, Pi3K-Akt and Nrg1-Erbb2/4 pathways. We also present an up-to-date account of landmark studies analyzing the effect of various genes such as Argin, Dystrophin, Fstl1, Meis1, Pitx2 and Pkm2 that are responsible for either inhibition or activation of CM cell division. All these reports describe bona fide therapeutically targets that could guide future clinical studies toward cardiac repair.
Collapse
|
3
|
Basic Pan-Cancer Analysis of the Carcinogenic Effects of Cyclin-Dependent Kinase 4 (CDK4) in Human Surface Tumors. JOURNAL OF HEALTHCARE ENGINEERING 2021; 2021:8493572. [PMID: 34422248 PMCID: PMC8371625 DOI: 10.1155/2021/8493572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 07/23/2021] [Indexed: 11/23/2022]
Abstract
Although the evidence based on current human, animal, or molecular biology can explain some of the relationships between CDK4 and cancer, there is no pan-cancer analysis of the gene CDK4 in human skin tumors. Therefore, the potential carcinogenic effects of CDK4 in 33 tumors were initially explored in the datasets of the GEO (Gene Expression Omnibus) and the CGA (Cancer Genome Atlas). We found that CDK4 was highly expressed in most cancers and that CDK4 performance levels significantly correlated with the prognosis of cancer patients. These were found in our preliminary exploration. In addition, we used the dataset in tumors such as cutaneous melanoma or lung adenocarcinoma and found increased levels of phosphorylation of r24 l/C/h/s. In addition, fibroblast infiltration associated with CDK4 cancer was observed in head and neck, sarcoma, and melanoma skin. Using this pan-cancer study, our group has provided a comprehensive preliminary demonstration of the oncogenic effects of the CDK4 gene on different human skin tumors.
Collapse
|
4
|
Wang W, Jiang Z, Zhang D, Fu L, Wan R, Hong K. Comparative Transcriptional Analysis of Pulmonary Arterial Hypertension Associated With Three Different Diseases. Front Cell Dev Biol 2021; 9:672159. [PMID: 34336829 PMCID: PMC8319719 DOI: 10.3389/fcell.2021.672159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 06/17/2021] [Indexed: 01/02/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a severe cardiovascular disorder with high mortality. Multiple clinical diseases can induce PAH, but the underlying molecular mechanisms shared in PAHs associated with different diseases remain unclear. The aim of this study is to explore the key candidate genes and pathways in PAH associated with congenital heart disease (CHD-PAH), PAH associated with connective tissue disease (CTD-PAH), and idiopathic PAH (IPAH). We performed differential expression analysis based on a public microarray dataset GSE113439 and identified 1,442 differentially expressed genes, of which 80.3% were upregulated. Subsequently, both pathway enrichment analysis and protein–protein interaction network analysis revealed that the “Cell cycle” and “DNA damage” processes were significantly enriched in PAH. The expression of seven upregulated candidate genes (EIF2AK2, TOPBP1, CDC5L, DHX15, and CUL1–3) and three downregulated candidate genes (DLL4, EGFL7, and ACE) were validated by qRT-PCR. Furthermore, cell cycle-related genes Cul1 and Cul2 were identified in pulmonary arterial endothelial cells (PAECs) in vitro. The result revealed an increased expression of Cul2 in PAECs after hypoxic treatment. Silencing Cul2 could inhibit overproliferation and migration of PAECs in hypoxia. Taken together, according to bioinformatic analyses, our work revealed that “Cell cycle” and “DNA damage” process-related genes and pathways were significantly dysregulated expressed in PAHs associated with three different diseases. This commonality in molecular discovery might broaden the genetic perspective and understanding of PAH. Besides, silencing Cul2 showed a protective effect in PAECs in hypoxia. The results may provide new treatment targets in multiple diseases induced by PAH.
Collapse
Affiliation(s)
- Wei Wang
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Zhenhong Jiang
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Jiangxi Key Laboratory of Molecular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Dandan Zhang
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Linghua Fu
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Rong Wan
- Jiangxi Key Laboratory of Molecular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Kui Hong
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China.,Jiangxi Key Laboratory of Molecular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| |
Collapse
|
5
|
Signaling pathways involved in cell cycle arrest during the DNA breaks. DNA Repair (Amst) 2021; 98:103047. [PMID: 33454524 DOI: 10.1016/j.dnarep.2021.103047] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 01/04/2021] [Indexed: 12/12/2022]
Abstract
Our genome bears tens of thousands of harms and devastations per day; In this regard, numerous sophisticated and complicated mechanisms are embedded by our cells in furtherance of remitting an unchanged and stable genome to their next generation. These mechanisms, that are collectively called DDR, have the duty of detecting the lesions and repairing them. it's necessary for the viability of any living cell that sustain the integrity and stability of its genetic content and this highlights the role of mediators that transduce the signals of DNA damage to the cell cycle in order to prevent the replication of a defective DNA. In this paper, we review the signaling pathways that lie between these processes and define how different ingredients of DDR are also able to affect the checkpoint signaling.
Collapse
|
6
|
Hashimoto Y, Tanaka H. Ongoing replication forks delay the nuclear envelope breakdown upon mitotic entry. J Biol Chem 2021; 296:100033. [PMID: 33148697 PMCID: PMC7948514 DOI: 10.1074/jbc.ra120.015142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 01/22/2023] Open
Abstract
DNA replication is a major contributor to genomic instability, and protection against DNA replication perturbation is essential for normal cell division. Certain types of replication stress agents, such as aphidicolin and hydroxyurea, have been shown to cause reversible replication fork stalling, wherein replisome complexes are stably maintained with competence to restart in the S phase of the cell cycle. If these stalled forks persist into the M phase without a replication restart, replisomes are disassembled in a p97-dependent pathway and under-replicated DNA is subjected to mitotic DNA repair synthesis. Here, using Xenopus egg extracts, we investigated the consequences that arise when stalled forks are released simultaneously with the induction of mitosis. Ara-cytidine-5'-triphosphate-induced stalled forks were able to restart with the addition of excess dCTP during early mitosis before the nuclear envelope breakdown (NEB). However, stalled forks could no longer restart efficiently after the NEB. Although replisome complexes were finally disassembled in a p97-dependent manner during mitotic progression whether or not fork stalling was relieved, the timing of the NEB was delayed with the ongoing forks, rather than the stalled forks, and the delay was dependent on Wee1/Myt1 kinase activities. Thus, ongoing DNA replication was found to be directly linked to the regulation of Wee1/Myt1 kinases to modulate cyclin-dependent kinase activities because of which DNA replication and mitosis occur in a mutually exclusive and sequential manner.
Collapse
Affiliation(s)
- Yoshitami Hashimoto
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan.
| | - Hirofumi Tanaka
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan
| |
Collapse
|
7
|
Franzin R, Stasi A, Fiorentino M, Stallone G, Cantaluppi V, Gesualdo L, Castellano G. Inflammaging and Complement System: A Link Between Acute Kidney Injury and Chronic Graft Damage. Front Immunol 2020; 11:734. [PMID: 32457738 PMCID: PMC7221190 DOI: 10.3389/fimmu.2020.00734] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
The aberrant activation of complement system in several kidney diseases suggests that this pillar of innate immunity has a critical role in the pathophysiology of renal damage of different etiologies. A growing body of experimental evidence indicates that complement activation contributes to the pathogenesis of acute kidney injury (AKI) such as delayed graft function (DGF) in transplant patients. AKI is characterized by the rapid loss of the kidney's excretory function and is a complex syndrome currently lacking a specific medical treatment to arrest or attenuate progression in chronic kidney disease (CKD). Recent evidence suggests that independently from the initial trigger (i.e., sepsis or ischemia/reperfusions injury), an episode of AKI is strongly associated with an increased risk of subsequent CKD. The AKI-to-CKD transition may involve a wide range of mechanisms including scar-forming myofibroblasts generated from different sources, microvascular rarefaction, mitochondrial dysfunction, or cell cycle arrest by the involvement of epigenetic, gene, and protein alterations leading to common final signaling pathways [i.e., transforming growth factor beta (TGF-β), p16 ink4a , Wnt/β-catenin pathway] involved in renal aging. Research in recent years has revealed that several stressors or complications such as rejection after renal transplantation can lead to accelerated renal aging with detrimental effects with the establishment of chronic proinflammatory cellular phenotypes within the kidney. Despite a greater understanding of these mechanisms, the role of complement system in the context of the AKI-to-CKD transition and renal inflammaging is still poorly explored. The purpose of this review is to summarize recent findings describing the role of complement in AKI-to-CKD transition. We will also address how and when complement inhibitors might be used to prevent AKI and CKD progression, therefore improving graft function.
Collapse
Affiliation(s)
- Rossana Franzin
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
- Department Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Alessandra Stasi
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Marco Fiorentino
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Giovanni Stallone
- Nephrology, Dialysis and Transplantation Unit, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
| | - Vincenzo Cantaluppi
- Department Translational Medicine, University of Piemonte Orientale, Novara, Italy
| | - Loreto Gesualdo
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - Giuseppe Castellano
- Nephrology, Dialysis and Transplantation Unit, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
- Nephrology, Dialysis and Transplantation Unit, Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy
| |
Collapse
|
8
|
Suppression of Angiogenesis by Targeting Cyclin-Dependent Kinase 7 in Human Umbilical Vein Endothelial Cells and Renal Cell Carcinoma: An In Vitro and In Vivo Study. Cells 2019; 8:cells8111469. [PMID: 31752390 PMCID: PMC6912535 DOI: 10.3390/cells8111469] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/28/2019] [Accepted: 11/14/2019] [Indexed: 12/11/2022] Open
Abstract
Cancer cells rely on aberrant transcription for growth and survival. Cyclin-dependent kinases (CDKs) play critical roles in regulating gene transcription by modulating the activity of RNA polymerase II (RNAPII). THZ1, a selective covalent inhibitor of CDK7, has antitumor effects in several human cancers. In this study, we investigated the role and therapeutic potential of CDK7 in regulating the angiogenic activity of endothelial cells and human renal cell carcinoma (RCC). Our results revealed that vascular endothelial growth factor (VEGF), a critical activator of angiogenesis, upregulated the expression of CDK7 and RNAPII, and the phosphorylation of RNAPII at serine 5 and 7 in human umbilical vein endothelial cells (HUVECs), indicating the transcriptional activity of CDK7 may be involved in VEGF-activated angiogenic activity of endothelium. Furthermore, through suppressing CDK7 activity, THZ1 suppressed VEGF-activated proliferation and migration, as well as enhanced apoptosis of HUVECs. Moreover, THZ1 inhibited VEGF-activated capillary tube formation and CDK7 knockdown consistently diminished tube formation in HUVECs. Additionally, THZ1 reduced VEGF expression in human RCC cells (786-O and Caki-2), and THZ1 treatment inhibited tumor growth, vascularity, and angiogenic marker (CD31) expression in RCC xenografts. Our results demonstrated that CDK7-mediated transcription was involved in the angiogenic activity of endothelium and human RCC. THZ1 suppressed VEGF-mediated VEGFR2 downstream activation of angiogenesis, providing a new perspective for antitumor therapy in RCC patients.
Collapse
|
9
|
Harari Y, Gershon L, Alonso-Perez E, Klein S, Berneman Y, Choudhari K, Singh P, Sau S, Liefshitz B, Kupiec M. Telomeres and stress in yeast cells: When genes and environment interact. Fungal Biol 2019; 124:311-315. [PMID: 32389293 DOI: 10.1016/j.funbio.2019.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/09/2019] [Accepted: 09/09/2019] [Indexed: 12/27/2022]
Abstract
Telomeres are structures composed of simple DNA repeats and specific proteins that protect the eukaryotic chromosomal ends from degradation, and facilitate the replication of the genome. They are central to the maintenance of the genome integrity, and play important roles in the development of cancer and in the process of aging in humans. The yeast Saccharomyces cerevisiae has greatly contributed to our understanding of basic telomere biology. Our laboratory has carried out systematic screen for mutants that affect telomere length, and identified ∼500 genes that, when mutated, affect telomere length. Remarkably, all ∼500 TLM (Telomere Length Maintenance) genes participate in a very tight homeostatic process, and it is enough to mutate one of them to change the steady-state telomere length. Despite this complex network of balances, it is also possible to change telomere length in yeast by applying several types of external stresses. We summarize our insights about the molecular mechanisms by which genes and environment interact to affect telomere length.
Collapse
Affiliation(s)
- Yaniv Harari
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Lihi Gershon
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Elisa Alonso-Perez
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Shir Klein
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Yael Berneman
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Karan Choudhari
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Pragyan Singh
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Soumitra Sau
- Amity Institute of Biotechnology, Amity University Kolkata, Kolkata, India
| | - Batia Liefshitz
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel
| | - Martin Kupiec
- School of Molecular Cell Biology and Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel.
| |
Collapse
|
10
|
Tang J, Bai J, Chen X, Zheng L, Liu H, Huang J. Two protein kinases UvPmk1 and UvCDC2 with significant functions in conidiation, stress response and pathogenicity of rice false smut fungus Ustilaginoidea virens. Curr Genet 2019; 66:409-420. [PMID: 31489464 DOI: 10.1007/s00294-019-01029-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/15/2019] [Accepted: 08/20/2019] [Indexed: 11/26/2022]
Abstract
Ustilaginoidea virens is an important fungus causing rice false smut, a devastating disease on spikelets of rice. In this study, we identified and characterized two CMGC (CDK/MAPK/GSK3/CLK) kinase genes, UvPmk1 and UvCDC2, in U. virens. Although UvPmk1 and UvCDC2 are, respectively, homologous to Fus3/Kss1 mitogen-activated protein kinases (MAPKs) and cyclin-dependent kinases (CDKs), they all have a conserved serine/threonine protein kinase domain. The qRT-PCR analysis of the relative expression of UvPmk1 and UvCDC2 during the infection of U. virens showed that these two genes were highly expressed during infection. UvPmk1 and UvCDC2 knockout mutants exhibited no significant changes in mycelial vegetative growth but decreases in conidiation. In addition, both UvPmk1 and UvCDC2 knockout mutants showed increases in tolerance to hyperosmotic and cell wall stresses, but they, respectively, exhibited decreases and increases in tolerance to oxidative stress compared with the wild-type strain HWD-2. Pathogenicity and infection assays demonstrated the defective growth of infection hyphae and significant loss of virulence in UvPmk1 and UvCDC2 knockout mutants. Taken together, our results demonstrate that UvPmk1 and UvCDC2 play important roles in the conidiation, stress response, and pathogenicity of U. virens.
Collapse
Affiliation(s)
- Jintian Tang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Jing Bai
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Xiaoyang Chen
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Lu Zheng
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Hao Liu
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China
| | - Junbin Huang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei, People's Republic of China.
| |
Collapse
|
11
|
A role for the yeast PCNA unloader Elg1 in eliciting the DNA damage checkpoint. Curr Genet 2019; 66:79-84. [PMID: 31332476 DOI: 10.1007/s00294-019-01020-7] [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: 07/14/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 12/28/2022]
Abstract
During cell proliferation, the genome is constantly threatened by cellular and external factors. When the DNA is damaged, or when its faithful duplication is delayed by DNA polymerase stalling, the cells induce a coordinated response termed the DNA damage response (DDR) or checkpoint. Elg1 forms an RFC-like complex in charge of unloading the DNA polymerase processively factor PCNA during DNA replication and DNA repair. Using checkpoint-inducible strains, a recently published paper (Sau et al. in mBio 10(3):e01159-19. https://doi.org/10.1128/mbio.01159-19, 2019) uncovered a role for Elg1 in eliciting the DNA damage checkpoint (DC), one of the branches of the DDR. The apical kinase Mec1/ATR phosphorylates Elg1, as well as the adaptor proteins Rad9/53BP1 and Dpb11/TopBP1, which are recruited to the site of DNA damage to amplify the checkpoint signal. In the absence of Elg1, Rad9 and Dpb11 are recruited but fail to be phosphorylated and the signal is therefore not amplified. Thus, Elg1 appears to coordinate DNA repair and the induction of the DNA damage checkpoint.
Collapse
|
12
|
Knoppert SN, Valentijn FA, Nguyen TQ, Goldschmeding R, Falke LL. Cellular Senescence and the Kidney: Potential Therapeutic Targets and Tools. Front Pharmacol 2019; 10:770. [PMID: 31354486 PMCID: PMC6639430 DOI: 10.3389/fphar.2019.00770] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/14/2019] [Indexed: 01/10/2023] Open
Abstract
Chronic kidney disease (CKD) is an increasing health burden (affecting approximately 13.4% of the population). Currently, no curative treatment options are available and treatment is focused on limiting the disease progression. The accumulation of senescent cells has been implicated in the development of kidney fibrosis by limiting tissue rejuvenation and through the secretion of pro-fibrotic and pro-inflammatory mediators termed as the senescence-associated secretory phenotype. The clearance of senescent cells in aging models results in improved kidney function, which shows promise for the options of targeting senescent cells in CKD. There are several approaches for the development of “senotherapies”, the most rigorous of which is the elimination of senescent cells by the so-called senolytic drugs either newly developed or repurposed for off-target effects in terms of selectively inducing apoptosis in senescent cells. Several chemotherapeutics and checkpoint inhibitors currently used in daily oncological practice show senolytic properties. However, the applicability of such senolytic compounds for the treatment of renal diseases has hardly been investigated. A serious concern is that systemic side effects will limit the use of senolytics for kidney fibrosis. Specifically targeting senescent cells and/or targeted drug delivery to the kidney might circumvent these side effects. In this review, we discuss the connection between CKD and senescence, the pharmacological options for targeting senescent cells, and the means to specifically target the kidney.
Collapse
Affiliation(s)
- Sebastian N Knoppert
- Department of Pathology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Floris A Valentijn
- Department of Pathology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Tri Q Nguyen
- Department of Pathology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Roel Goldschmeding
- Department of Pathology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Lucas L Falke
- Department of Pathology, University Medical Center Utrecht, Utrecht, Netherlands.,Department of Internal Medicine, Diakonessenhuis, University Medical Center Utrecht, Utrecht, Netherlands
| |
Collapse
|
13
|
E3 Ubiquitin Ligase TRIM Proteins, Cell Cycle and Mitosis. Cells 2019; 8:cells8050510. [PMID: 31137886 PMCID: PMC6562728 DOI: 10.3390/cells8050510] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/22/2022] Open
Abstract
The cell cycle is a series of events by which cellular components are accurately segregated into daughter cells, principally controlled by the oscillating activities of cyclin-dependent kinases (CDKs) and their co-activators. In eukaryotes, DNA replication is confined to a discrete synthesis phase while chromosome segregation occurs during mitosis. During mitosis, the chromosomes are pulled into each of the two daughter cells by the coordination of spindle microtubules, kinetochores, centromeres, and chromatin. These four functional units tie chromosomes to the microtubules, send signals to the cells when the attachment is completed and the division can proceed, and withstand the force generated by pulling the chromosomes to either daughter cell. Protein ubiquitination is a post-translational modification that plays a central role in cellular homeostasis. E3 ubiquitin ligases mediate the transfer of ubiquitin to substrate proteins determining their fate. One of the largest subfamilies of E3 ubiquitin ligases is the family of the tripartite motif (TRIM) proteins, whose dysregulation is associated with a variety of cellular processes and directly involved in human diseases and cancer. In this review we summarize the current knowledge and emerging concepts about TRIMs and their contribution to the correct regulation of cell cycle, describing how TRIMs control the cell cycle transition phases and their involvement in the different functional units of the mitotic process, along with implications in cancer progression.
Collapse
|
14
|
Linking the organization of DNA replication with genome maintenance. Curr Genet 2019; 65:677-683. [PMID: 30600398 DOI: 10.1007/s00294-018-0923-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/17/2018] [Accepted: 12/19/2018] [Indexed: 12/11/2022]
Abstract
The spatial and temporal organization of genome duplication, also referred to as the replication program, is defined by the distribution and the activities of the sites of replication initiation across the genome. Alterations to the replication profile are associated with cell fate changes during development and in pathologies, but the importance of undergoing S phase with distinct and specific programs remains largely unexplored. We have recently addressed this question, focusing on the interplay between the replication program and genome maintenance. In particular, we demonstrated that when cells encounter challenges to DNA synthesis, the organization of DNA replication drives the response to replication stress that is mediated by the ATR/Rad3 checkpoint pathway, thus shaping the pattern of genome instability along the chromosomes. In this review, we present the major findings of our study and discuss how they may bring new perspectives to our understanding of the biological importance of the replication program.
Collapse
|