1
|
Iglesias-Romero AB, Soto T, Flor-Parra I, Salas-Pino S, Ruiz-Romero G, Gould KL, Cansado J, Daga RR. MAPK-dependent control of mitotic progression in S. pombe. BMC Biol 2024; 22:71. [PMID: 38523261 PMCID: PMC10962199 DOI: 10.1186/s12915-024-01865-6] [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: 02/25/2023] [Accepted: 03/08/2024] [Indexed: 03/26/2024] Open
Abstract
BACKGROUND Mitogen-activated protein kinases (MAPKs) preserve cell homeostasis by transducing physicochemical fluctuations of the environment into multiple adaptive responses. These responses involve transcriptional rewiring and the regulation of cell cycle transitions, among others. However, how stress conditions impinge mitotic progression is largely unknown. The mitotic checkpoint is a surveillance mechanism that inhibits mitotic exit in situations of defective chromosome capture, thus preventing the generation of aneuploidies. In this study, we investigate the role of MAPK Pmk1 in the regulation of mitotic exit upon stress. RESULTS We show that Schizosaccharomyces pombe cells lacking Pmk1, the MAP kinase effector of the cell integrity pathway (CIP), are hypersensitive to microtubule damage and defective in maintaining a metaphase arrest. Epistasis analysis suggests that Pmk1 is involved in maintaining spindle assembly checkpoint (SAC) signaling, and its deletion is additive to the lack of core SAC components such as Mad2 and Mad3. Strikingly, pmk1Δ cells show up to twofold increased levels of the anaphase-promoting complex (APC/C) activator Cdc20Slp1 during unperturbed growth. We demonstrate that Pmk1 physically interacts with Cdc20Slp1 N-terminus through a canonical MAPK docking site. Most important, the Cdc20Slp1 pool is rapidly degraded in stressed cells undergoing mitosis through a mechanism that requires MAPK activity, Mad3, and the proteasome, thus resulting in a delayed mitotic exit. CONCLUSIONS Our data reveal a novel function of MAPK in preventing mitotic exit and activation of cytokinesis in response to stress. The regulation of Cdc20Slp1 turnover by MAPK Pmk1 provides a key mechanism by which the timing of mitotic exit can be adjusted relative to environmental conditions.
Collapse
Affiliation(s)
| | - Terersa Soto
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, Murcia, 30071, Spain
| | - Ignacio Flor-Parra
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain
| | - Silvia Salas-Pino
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain
| | - Gabriel Ruiz-Romero
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain
| | - Kathleen L Gould
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, 37240, USA
| | - José Cansado
- Yeast Physiology Group, Department of Genetics and Microbiology, Facultad de Biología, Universidad de Murcia, Murcia, 30071, Spain.
| | - Rafael R Daga
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide, Seville, 41013, Spain.
| |
Collapse
|
2
|
Translin facilitates RNA polymerase II dissociation and suppresses genome instability during RNase H2- and Dicer-deficiency. PLoS Genet 2022; 18:e1010267. [PMID: 35714159 PMCID: PMC9246224 DOI: 10.1371/journal.pgen.1010267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/30/2022] [Accepted: 05/19/2022] [Indexed: 11/25/2022] Open
Abstract
The conserved nucleic acid binding protein Translin contributes to numerous facets of mammalian biology and genetic diseases. It was first identified as a binder of cancer-associated chromosomal translocation breakpoint junctions leading to the suggestion that it was involved in genetic recombination. With a paralogous partner protein, Trax, Translin has subsequently been found to form a hetero-octomeric RNase complex that drives some of its functions, including passenger strand removal in RNA interference (RNAi). The Translin-Trax complex also degrades the precursors to tumour suppressing microRNAs in cancers deficient for the RNase III Dicer. This oncogenic activity has resulted in the Translin-Trax complex being explored as a therapeutic target. Additionally, Translin and Trax have been implicated in a wider range of biological functions ranging from sleep regulation to telomere transcript control. Here we reveal a Trax- and RNAi-independent function for Translin in dissociating RNA polymerase II from its genomic template, with loss of Translin function resulting in increased transcription-associated recombination and elevated genome instability. This provides genetic insight into the longstanding question of how Translin might influence chromosomal rearrangements in human genetic diseases and provides important functional understanding of an oncological therapeutic target. Human genetic diseases, including cancers, are frequently driven by substantial changes to chromosomes, including translocations, where one arm of a chromosome is exchanged for another. The human nucleic acid binding protein Translin was first identified by its ability to bind to the chromosomal sites at which some of these translocations occur. This resulted in Translin being implicated in the mechanism that generated the translocation and thus the associated disease state. However, since its discovery there has been little evidence to directly indicate Translin does contribute to this process. It is, however, known to contribute to a number of biological functions including, amongst others, neurological regulation, sleep control, vascular stiffening, cancer immunomodulation and it has been recently identified as a potential therapeutic target in some cancers. Here we demonstrate that Translin has conserved function in genome stability maintenance when other primary pathways are defective, a function independent of a key binding partner protein, Trax. Specifically, we demonstrate that Translin contributes to minimizing the deleterious genome destabilizing effects of retaining gene expression machineries on chromosomes. This offers the first evidence for how Translin might contribute to genetic disease-causing chromosomal changes and offers insight to inform therapeutic design.
Collapse
|
3
|
Abstract
DNA double-strand breaks (DSBs), arising during normal DNA metabolism or following exposure to mutagenic agents such as ionizing radiation can lead to chromosomal rearrangements and genome instability, and are potentially lethal if unrepaired. Therefore, understanding the mechanisms of DSB repair and misrepair, and identifying the factors involved in these processes is of biological as well as medical interest. Here we describe a DSB assay in Schizosaccharomyces pombe that can be used to identify and quantify different repair, misrepair, and failed repair events resulting from a site-specific DSB within the context of a nonessential minichromosome, Ch16 This assay can be used to determine the contribution of most genes or genetic backgrounds to DSB repair and genome stability, and can also provide mechanistic insights into their function.
Collapse
Affiliation(s)
- Chen-Chun Pai
- CRUK-MRC Institute for Radiation Oncology, University of Oxford, Department of Oncology, ORCRB, Oxford OX3 7DQ, United Kingdom
| | - Elizabeth Blaikley
- CRUK-MRC Institute for Radiation Oncology, University of Oxford, Department of Oncology, ORCRB, Oxford OX3 7DQ, United Kingdom
| | - Timothy C Humphrey
- CRUK-MRC Institute for Radiation Oncology, University of Oxford, Department of Oncology, ORCRB, Oxford OX3 7DQ, United Kingdom
| |
Collapse
|
4
|
Abstract
The fission yeast Schizosaccharomyces pombe is an excellent model organism to study DNA metabolism, in which the DNA replication and repair mechanisms are evolutionarily conserved. In this introduction we describe a range of methods commonly used to study aspects of DNA metabolism in fission yeast, focusing on approaches used for the analysis of genome stability, DNA replication, and DNA repair. We describe the use of a minichromosome, Ch16, for monitoring different aspects of genome stability. We introduce two-dimensional gel electrophoresis and immunofluorescent visualization of combed DNA molecules for the analysis of DNA replication. Further, we introduce a pulsed field gel electrophoresis (PFGE) assay to physically monitor chromosome integrity, which can be used in conjunction with a DNA double-strand break (DSB) repair assay to genetically quantitate different DSB repair and misrepair outcomes, including gross chromosomal rearrangements, in fission yeast.
Collapse
Affiliation(s)
- Francisco Antequera
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca, Salamanca 37007, Spain
| | - Timothy C Humphrey
- CRUK-MRC Oxford Institute for Radiation Oncology, University of Oxford, OX3 7DQ, United Kingdom
| |
Collapse
|
5
|
Li T, Mary H, Grosjean M, Fouchard J, Cabello S, Reyes C, Tournier S, Gachet Y. MAARS: a novel high-content acquisition software for the analysis of mitotic defects in fission yeast. Mol Biol Cell 2017; 28:1601-1611. [PMID: 28450455 PMCID: PMC5469604 DOI: 10.1091/mbc.e16-10-0723] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 03/14/2017] [Accepted: 04/20/2017] [Indexed: 01/08/2023] Open
Abstract
Faithful segregation of chromosomes during cell division relies on multiple processes such as chromosome attachment and correct spindle positioning. Yet mitotic progression is defined by multiple parameters, which need to be quantitatively evaluated. To study the spatiotemporal control of mitotic progression, we developed a high-content analysis (HCA) approach that combines automated fluorescence microscopy with real-time quantitative image analysis and allows the unbiased acquisition of multiparametric data at the single-cell level for hundreds of cells simultaneously. The Mitotic Analysis and Recording System (MAARS) provides automatic and quantitative single-cell analysis of mitotic progression on an open-source platform. It can be used to analyze specific characteristics such as cell shape, cell size, metaphase/anaphase delays, and mitotic abnormalities including spindle mispositioning, spindle elongation defects, and chromosome segregation defects. Using this HCA approach, we were able to visualize rare and unexpected events of error correction during anaphase in wild-type or mutant cells. Our study illustrates that such an expert system of mitotic progression is able to highlight the complexity of the mechanisms required to prevent chromosome loss during cell division.
Collapse
Affiliation(s)
- Tong Li
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Hadrien Mary
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Marie Grosjean
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Jonathan Fouchard
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Simon Cabello
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Céline Reyes
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Sylvie Tournier
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| | - Yannick Gachet
- Laboratoire de Biologie Cellulaire et Moléculaire du Controle de la Prolifération, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex, France
| |
Collapse
|