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Lazo PA. Nuclear functions regulated by the VRK1 kinase. Nucleus 2024; 15:2353249. [PMID: 38753965 DOI: 10.1080/19491034.2024.2353249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/06/2024] [Indexed: 05/18/2024] Open
Abstract
In the nucleus, the VRK1 Ser-Thr kinase is distributed in nucleoplasm and chromatin, where it has different roles. VRK1 expression increases in response to mitogenic signals. VRK1 regulates cyclin D1 expression at G0 exit and facilitates chromosome condensation at the end of G2 and G2/M progression to mitosis. These effects are mediated by the phosphorylation of histone H3 at Thr3 by VRK1, and later in mitosis by haspin. VRK1 regulates the apigenetic patterns of histones in processes requiring chromating remodeling, such as transcription, replication and DNA repair. VRK1 is overexpressed in tumors, facilitating tumor progression and resistance to genotoxic treatments. VRK1 also regulates the organization of Cajal bodies assembled on coilin, which are necessary for the assembly of different types of RNP complexes. VRK1 pathogenic variants cuase defects in Cajal bodies, functionally altering neurons with long axons and leading to neurological diseases, such as amyotrophic laterla sclerosis, spinal muscular atrophy, distal hereditay motor neuropathies and Charcot-Marie-Tooth.
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Affiliation(s)
- Pedro A Lazo
- Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain
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Campos-Díaz A, Morejón-García P, Monte-Serrano E, Ros-Pardo D, Marcos-Alcalde I, Gómez-Puertas P, Lazo PA. Pathogenic effects of Leu200Pro and Arg387His VRK1 protein variants on phosphorylation targets and H4K16 acetylation in distal hereditary motor neuropathy. J Mol Med (Berl) 2024; 102:801-817. [PMID: 38554151 PMCID: PMC11106162 DOI: 10.1007/s00109-024-02442-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 03/07/2024] [Accepted: 03/21/2024] [Indexed: 04/01/2024]
Abstract
Rare recessive variants in the human VRK1 gene are associated with several motor neuron diseases (MND), such as amyotrophic lateral sclerosis, spinal muscular atrophy, or distal hereditary motor neuropathies (dHMN). A case with dHMN carrying two novel VRK1 gene variants, expressing Leu200Pro (L200P) and Arg387His (R387H) variant proteins, identified that these protein variants are functionally different. The Leu200Pro variant shares with several variants in the catalytic domain the loss of the kinase activity on different substrates, such as histones, p53, or coilin. However, the distal Arg387His variant and the distal Trp375* (W375X) chinese variant, both located at the end of the low complexity C-terminal region and proximal to the termination codon, retain their catalytic activity on some substrates, and mechanistically their functional impairment is different. The L200P variant, as well as most VRK1 pathogenic variants, impairs the phosphorylation of BAF and histone H4K16 acetylation, which are required for DNA attachment to the nuclear envelope and chromatin accessibility to DNA repair mechanisms, respectively. The R387H variant impairs phosphorylation of H2AX, an early step in different types of DNA damage responses. The functional variability of VRK1 protein variants and their different combinations are a likely contributor to the clinical phenotypic heterogeneity of motor neuron and neurological diseases associated with rare VRK1 pathogenic variants. KEY MESSAGES: VRK1 variants implicated in motor neuron diseases are functionally different. The L200P variant is kinase inactive, and the R387H variant is partially active. VRK1 variants alter H4K16 acetylation and loss of coilin and BAF phosphorylation. VRK1 variants alter Cajal bodies and DNA damage responses. VRK1 variant combination determines the neurological phenotype heterogeneity.
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Affiliation(s)
- Aurora Campos-Díaz
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, 37007, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007, Salamanca, Spain
| | - Patricia Morejón-García
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, 37007, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007, Salamanca, Spain
| | - Eva Monte-Serrano
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, 37007, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007, Salamanca, Spain
| | - David Ros-Pardo
- Molecular Modeling Group, Centro de Biología Molecular Severo Ochoa, CBMSO (CSIC-UAM), 28040, Madrid, Spain
| | - Iñigo Marcos-Alcalde
- Molecular Modeling Group, Centro de Biología Molecular Severo Ochoa, CBMSO (CSIC-UAM), 28040, Madrid, Spain
| | - Paulino Gómez-Puertas
- Molecular Modeling Group, Centro de Biología Molecular Severo Ochoa, CBMSO (CSIC-UAM), 28040, Madrid, Spain
| | - Pedro A Lazo
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC), Universidad de Salamanca, 37007, Salamanca, Spain.
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007, Salamanca, Spain.
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Lazo PA, Morejón-García P. VRK1 variants at the cross road of Cajal body neuropathogenic mechanisms in distal neuropathies and motor neuron diseases. Neurobiol Dis 2023; 183:106172. [PMID: 37257665 DOI: 10.1016/j.nbd.2023.106172] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/09/2023] [Accepted: 05/24/2023] [Indexed: 06/02/2023] Open
Abstract
Distal hereditary neuropathies and neuro motor diseases are complex neurological phenotypes associated with pathogenic variants in a large number of genes, but in some the origin is unknown. Recently, rare pathogenic variants of the human VRK1 gene have been associated with these neurological phenotypes. All VRK1 pathogenic variants are recessive, and their clinical presentation occurs in either homozygous or compound heterozygous patients. The pathogenic VRK1 gene pathogenic variants are located in three clusters within the protein sequence. The main, and initial, shared clinical phenotype among VRK1 pathogenic variants is a distal progressive loss of motor and/or sensory function, which includes diseases such as spinal muscular atrophy, Charcot-Marie-Tooth, amyotrophic lateral sclerosis and hereditary spastic paraplegia. In most cases, symptoms start early in infancy, or in utero, and are slowly progressive. Additional neurological symptoms vary among non-related patients, probably because of their different VRK1 variants and their genetic background. The underlying common pathogenic mechanism, by its functional impairment, is a likely consequence of the roles that the VRK1 protein plays in the regulation on the stability and assembly of Cajal bodies, which affect RNA maturation and processing, neuronal migration of RNPs along axons, and DNA-damage responses. Alterations of these processes are associated with several neuro sensory or motor syndromes. The clinical heterogeneity of the neurological phenotypes associated with VRK1 is a likely consequence of the protein complexes in which VRK1 is integrated, which include several proteins known to be associated with Cajal bodies and DNA damage responses. Several hereditary distal neurological diseases are a consequence of pathogenic variants in genes that alter these cellular functions. We conclude that VRK1-related distal hereditary neuropathies and motor neuron diseases represent a novel subgroup of Cajal body related neurological syndromes.
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Affiliation(s)
- Pedro A Lazo
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain.
| | - Patricia Morejón-García
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca, Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain.
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The VRK1 chromatin kinase regulates the acetyltransferase activity of Tip60/KAT5 by sequential phosphorylations in response to DNA damage. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - GENE REGULATORY MECHANISMS 2022; 1865:194887. [DOI: 10.1016/j.bbagrm.2022.194887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/13/2022] [Accepted: 10/15/2022] [Indexed: 11/06/2022]
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Frasquet M, Sevilla T. Hereditary motor neuropathies. Curr Opin Neurol 2022; 35:562-570. [PMID: 35942667 DOI: 10.1097/wco.0000000000001087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Distal hereditary motor neuropathies (dHMN) are a clinically and genetically diverse group of disorders that are characterized by length-dependent axonal degeneration of lower motor neurons. In this review, we will provide an overview of dHMN, and we will correlate the distinct clinical subtypes with their causative genes, focusing on the most recent advances in the field. RECENT FINDINGS Despite the massive use of new-generation sequencing (NGS) and the discovery of new genes, only a third of dHMN patients receive a molecular diagnosis. Thanks to international cooperation between researchers, new genes have been implicated in dHMN, such as SORD and VWA1 . Mutations in SORD are the most frequent cause of autosomal recessive forms of dHMN. As a result of these findings, the potential benefits of some pharmacological compounds are being studied in cell and animal models, mainly targeting axonal transport and metabolic pathways. SUMMARY Despite the wide use of NGS, the diagnosis of dHMN remains a challenge. The low prevalence of dHMN makes international cooperation necessary in order to discover new genes and causal mechanisms. Genetic diagnosis of patients and identification of new pathomechanism are essential for the development of therapeutical clinical trials.
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Affiliation(s)
- Marina Frasquet
- Department of Neurology, Hospital Universitari Doctor Peset
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain
| | - Teresa Sevilla
- Neuromuscular Diseases Unit, Department of Neurology, Hospital Universitari i Politècnic La Fe
- Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) Spain
- Universitat de València, Valencia, Spain
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Morejon-Garcia P, Keren B, Marcos-Alcalde I, Gomez-Puertas P, Mochel F, Lazo PA. Dysfunctional Homozygous VRK1-D263G Variant Impairs the Assembly of Cajal Bodies and DNA Damage Response in Hereditary Spastic Paraplegia. NEUROLOGY-GENETICS 2021; 7:e624. [PMID: 34504951 PMCID: PMC8422991 DOI: 10.1212/nxg.0000000000000624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/26/2021] [Indexed: 11/29/2022]
Abstract
Background and Objectives To conduct a genetic and molecular functional study of a family with members affected of hereditary spastic paraplegia (HSP) of unknown origin and carrying a novel pathogenic vaccinia-related kinase 1 (VRK1) variant. Methods Whole-exome sequencing was performed in 2 patients, and their parents diagnosed with HSP. The novel VRK1 variant was detected by whole-exome sequencing, molecularly modeled and biochemically characterized in kinase assays. Functionally, we studied the role of this VRK1 variant in DNA damage response and its effect on the assembly of Cajal bodies (CBs). Results We have identified a very rare homozygous variant VRK1-D263G with a neurologic phenotype associated with HSP and moderate intellectual disability. The molecular modeling of this VRK1 variant protein predicted an alteration in the folding of a loop that interferes with the access to the kinase catalytic site. The VRK1-D263G variant is kinase inactive and does not phosphorylate histones H2AX and H3, transcription factors activating transcription factor 2 and p53, coilin needed for assembly of CBs, and p53 binding protein 1, a DNA repair protein. Functionally, this VRK1 variant protein impairs CB formation and the DNA damage response. Discussion This report expands the neurologic spectrum of neuromotor syndromes associated with a new and rare VRK1 variant, representing a novel pathogenic participant in complicated HSP and demonstrates that CBs and the DNA damage response are impaired in these patients.
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Affiliation(s)
- Patricia Morejon-Garcia
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Boris Keren
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Iñigo Marcos-Alcalde
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Paulino Gomez-Puertas
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Fanny Mochel
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Pedro A Lazo
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
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Navarro-Carrasco E, Lazo PA. VRK1 Depletion Facilitates the Synthetic Lethality of Temozolomide and Olaparib in Glioblastoma Cells. Front Cell Dev Biol 2021; 9:683038. [PMID: 34195200 PMCID: PMC8237761 DOI: 10.3389/fcell.2021.683038] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Background Glioblastomas treated with temozolomide frequently develop resistance to pharmacological treatments. Therefore, there is a need to find alternative drug targets to reduce treatment resistance based on tumor dependencies. A possibility is to target simultaneously two proteins from different DNA-damage repair pathways to facilitate tumor cell death. Therefore, we tested whether targeting the human chromatin kinase VRK1 by RNA interference can identify this protein as a novel molecular target to reduce the dependence on temozolomide in combination with olaparib, based on synthetic lethality. Materials and Methods Depletion of VRK1, an enzyme that regulates chromatin dynamic reorganization and facilitates resistance to DNA damage, was performed in glioblastoma cells treated with temozolomide, an alkylating agent used for GBM treatment; and olaparib, an inhibitor of PARP-1, used as sensitizer. Two genetically different human glioblastoma cell lines, LN-18 and LN-229, were used for these experiments. The effect on the DNA-damage response was followed by determination of sequential steps in this process: H4K16ac, γH2AX, H4K20me2, and 53BP1. Results The combination of temozolomide and olaparib increased DNA damage detected by labeling free DNA ends, and chromatin relaxation detected by H4K16ac. The combination of both drugs, at lower doses, resulted in an increase in the DNA damage response detected by the formation of γH2AX and 53BP1 foci. VRK1 depletion did not prevent the generation of DNA damage in TUNEL assays, but significantly impaired the DNA damage response induced by temozolomide and olaparib, and mediated by γH2AX, H4K20me2, and 53BP1. The combination of these drugs in VRK1 depleted cells resulted in an increase of glioblastoma cell death detected by annexin V and the processing of PARP-1 and caspase-3. Conclusion Depletion of the chromatin kinase VRK1 promotes tumor cell death at lower doses of a combination of temozolomide and olaparib treatments, and can be a novel alternative target for therapies based on synthetic lethality.
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Affiliation(s)
- Elena Navarro-Carrasco
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca-IBSAL, Hospital Universitario de Salamanca, Salamanca, Spain
| | - Pedro A Lazo
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca-IBSAL, Hospital Universitario de Salamanca, Salamanca, Spain
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Campillo-Marcos I, García-González R, Navarro-Carrasco E, Lazo PA. The human VRK1 chromatin kinase in cancer biology. Cancer Lett 2021; 503:117-128. [PMID: 33516791 DOI: 10.1016/j.canlet.2020.12.032] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/30/2020] [Accepted: 12/21/2020] [Indexed: 01/08/2023]
Abstract
VRK1 is a nuclear Ser-Thr chromatin kinase that does not mutate in cancer, and is overexpressed in many types of tumors and associated with a poor prognosis. Chromatin VRK1 phosphorylates several transcription factors, including p53, histones and proteins implicated in DNA damage response pathways. In the context of cell proliferation, VRK1 regulates entry in cell cycle, chromatin condensation in G2/M, Golgi fragmentation, Cajal body dynamics and nuclear envelope assembly in mitosis. This kinase also controls the initial chromatin relaxation associated with histone acetylation, and the non-homologous-end joining (NHEJ) DNA repair pathway, which involves sequential steps such as γH2AX, NBS1 and 53BP1 foci formation, all phosphorylated by VRK1, in response to ionizing radiation or chemotherapy. In addition, VRK1 can be an alternative target for therapies based on synthetic lethality strategies. Therefore, VRK1 roles on proliferation have a pro-tumorigenic effect. Functions regulating chromatin stability and DNA damage responses have a protective anti-tumor role in normal cells, but in tumor cells can also facilitate resistance to genotoxic treatments.
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Affiliation(s)
- Ignacio Campillo-Marcos
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular Del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, 37007 Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain.
| | - Raúl García-González
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular Del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, 37007 Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain.
| | - Elena Navarro-Carrasco
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular Del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, 37007 Salamanca, Spain; Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, 37007 Salamanca, Spain.
| | - Pedro A Lazo
- Molecular Mechanisms of Cancer Program, Instituto de Biología Molecular y Celular Del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, 37007 Salamanca, Spain.
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VRK1 Phosphorylates Tip60/KAT5 and Is Required for H4K16 Acetylation in Response to DNA Damage. Cancers (Basel) 2020; 12:cancers12102986. [PMID: 33076429 PMCID: PMC7650776 DOI: 10.3390/cancers12102986] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 10/01/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
Dynamic remodeling of chromatin requires acetylation and methylation of histones, frequently affecting the same lysine residue. These alternative epigenetic modifications require the coordination of enzymes, writers and erasers, mediating them such as acetylases and deacetylases. In cells in G0/G1, DNA damage induced by doxorubicin causes an increase in histone H4K16ac, a marker of chromatin relaxation. In this context, we studied the role that VRK1, a chromatin kinase activated by DNA damage, plays in this early step. VRK1 depletion or MG149, a Tip60/KAT5 inhibitor, cause a loss of H4K16ac. DNA damage induces the phosphorylation of Tip60 mediated by VRK1 in the chromatin fraction. VRK1 directly interacts with and phosphorylates Tip60. Furthermore, the phosphorylation of Tip60 induced by doxorubicin is lost by depletion of VRK1 in both ATM +/+ and ATM-/- cells. Kinase-active VRK1, but not kinase-dead VRK1, rescues Tip60 phosphorylation induced by DNA damage independently of ATM. The Tip60 phosphorylation by VRK1 is necessary for the activating acetylation of ATM, and subsequent ATM autophosphorylation, and both are lost by VRK1 depletion. These results support that the VRK1 chromatin kinase is an upstream regulator of the initial acetylation of histones, and an early step in DNA damage responses (DDR).
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