RESUMO
Spatial compartmentalization is a key facet of protein quality control that serves to store disassembled or non-native proteins until triage to the refolding or degradation machinery can occur in a regulated manner. Yeast cells sequester nuclear proteins at intranuclear quality control bodies (INQ) in response to various stresses, although the regulation of this process remains poorly understood. Here we reveal the SUMO modification of the small heat shock protein Btn2 under DNA damage and place Btn2 SUMOylation in a pathway promoting protein clearance from INQ structures. Along with other chaperones, and degradation machinery, Btn2-SUMO promotes INQ clearance from cells recovering from genotoxic stress. These data link small heat shock protein post-translational modification to the regulation of protein sequestration in the yeast nucleus.
Assuntos
Proteínas de Choque Térmico Pequenas , Corpos de Inclusão Intranuclear , Proteínas de Transporte Vesicular , Dano ao DNA , Proteínas de Choque Térmico Pequenas/genética , Proteínas de Choque Térmico Pequenas/metabolismo , Corpos de Inclusão Intranuclear/genética , Corpos de Inclusão Intranuclear/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Sumoilação , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismoRESUMO
Temperature-sensitive (TS) alleles create tunable thermoswitches to deplete essential cellular activities and are used to dissect gene function. In their recent study, Link and colleagues (Schramm et al 2023) use a CRISPR-based approach to systematically create TS alleles across essential genes in E. coli.
RESUMO
There has been growing appreciation that transcription is an endogenous source of replication stress and must be coordinated with replication. In this issue, Bhowmick et al.1 uncover a protective mechanism that prevents co-directional transcription-replication conflicts (TRCs) from becoming genotoxic.
Assuntos
Replicação do DNA , Transcrição Gênica , Dano ao DNARESUMO
DNA replication is a vulnerable time for genome stability maintenance. Intrinsic stressors, as well as oncogenic stress, can challenge replication by fostering conflicts with transcription and stabilizing DNA:RNA hybrids. RAD18 is an E3 ubiquitin ligase for PCNA that is involved in coordinating DNA damage tolerance pathways to preserve genome stability during replication. In this study, we show that RAD18 deficient cells have higher levels of transcription-replication conflicts and accumulate DNA:RNA hybrids that induce DNA double strand breaks and replication stress. We find that these effects are driven in part by failure to recruit the Fanconi Anemia protein FANCD2 at difficult to replicate and R-loop prone genomic sites. FANCD2 activation caused by splicing inhibition or aphidicolin treatment is critically dependent on RAD18 activity. Thus, we highlight a RAD18-dependent pathway promoting FANCD2-mediated suppression of R-loops and transcription-replication conflicts.
Assuntos
Reparo do DNA , Anemia de Fanconi , Humanos , Reparo do DNA/genética , Anemia de Fanconi/genética , Anemia de Fanconi/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , DNA/genética , Dano ao DNA/genética , Replicação do DNA/genética , RNA , Instabilidade Genômica/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismoRESUMO
In the past decade, there has been a growing appreciation for R-loop structures as important regulators of the epigenome, telomere maintenance, DNA repair, and replication. Given these numerous functions, dozens, or potentially hundreds, of proteins could serve as direct or indirect regulators of R-loop writing, reading, and erasing. In order to understand common properties shared amongst potential R-loop binding proteins, we mined published proteomic studies and distilled 10 features that were enriched in R-loop binding proteins compared with the rest of the proteome. Applying an easy-ensemble machine learning approach, we used these R-loop binding protein-specific features along with their amino acid composition to create random forest classifiers that predict the likelihood of a protein to bind to R-loops. Known R-loop regulating pathways such as splicing, DNA damage repair and chromatin remodeling are highly enriched in our datasets, and we validate 2 new R-loop binding proteins LIG1 and FXR1 in human cells. Together these datasets provide a reference to pursue analyses of novel R-loop regulatory proteins.
Assuntos
Proteínas de Transporte , Estruturas R-Loop , Proteínas de Transporte/genética , Reparo do DNA , Humanos , Proteômica , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genéticaRESUMO
The nucleus is a highly organized organelle with an intricate substructure of chromatin, RNAs, and proteins. This environment represents a challenge for maintaining protein quality control, since non-native proteins may interact inappropriately with other macromolecules and thus interfere with their function. Maintaining a healthy nuclear proteome becomes imperative during times of stress, such as upon DNA damage, heat shock, or starvation, when the proteome must be remodeled to effect cell survival. This is accomplished with the help of nuclear-specific chaperones, degradation pathways, and specialized structures known as protein quality control (PQC) sites that sequester proteins to help rapidly remodel the nuclear proteome. In this review, we focus on the current knowledge of PQC sites in Saccharomyces cerevisiae, particularly on a specialized nuclear PQC site called the intranuclear quality control site, a poorly understood nuclear inclusion that coordinates dynamic proteome triage decisions in yeast.
Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Núcleo Celular/genética , Núcleo Celular/metabolismo , Proteínas Nucleares/metabolismo , Proteoma/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Chromatin structure and underlying DNA accessibility is modulated by the incorporation of histone variants. H2A.Z, a variant of the H2A core histone family, plays a distinct and essential role in a diverse set of biological functions including gene regulation and maintenance of heterochromatin-euchromatin boundaries. Although it is currently unclear how the replacement of H2A with H2A.Z can regulate gene expression, the variance in their amino acid sequence likely contributes to their functional differences. To tease apart regions of H2A.Z that confer its unique identity, a set of plasmids expressing H2A-H2A.Z hybrids from the native H2A.Z promoter were examined for their ability to recapitulate H2A.Z function. First, we found that the H2A.Z M6 region was necessary and sufficient for interaction with the SWR1-C chromatin remodeler. Remarkably, the combination of only 9 amino acid changes, the H2A.Z M6 region, K79 and L81 (two amino acids in the α2-helix), were sufficient to fully rescue growth phenotypes of the htz1Δ mutant. Furthermore, combining three unique H2A.Z regions (K79 and L81, M6, C-terminal tail) was sufficient for expression of H2A.Z-dependent heterochromatin-proximal genes and GAL1 derepression. Surprisingly, hybrid constructs that restored the transcription of H2A.Z-dependent genes, did not fully recapitulate patterns of H2A.Z-specific enrichment at the tested loci. This suggested that H2A.Z function in transcription regulation may be at least partially independent of its specific localization in chromatin. Together, this work has identified three regions that can confer specific H2A.Z-identity to replicative H2A, furthering our understanding of what makes a histone variant a variant.
Assuntos
Adenosina Trifosfatases/genética , Cromatina/genética , Galactoquinase/genética , Histonas/genética , Proteínas de Saccharomyces cerevisiae/genética , Trifosfato de Adenosina/genética , Montagem e Desmontagem da Cromatina/genética , Regulação Fúngica da Expressão Gênica/genética , Variação Genética/genética , Heterocromatina/genética , Humanos , Nucleossomos/genética , Fenótipo , Saccharomyces cerevisiae/genéticaRESUMO
About 10-15% of all human cancer cells employ a telomerase-independent recombination-based telomere maintenance method, known as alternative lengthening of telomere (ALT), of which the full mechanism remains incompletely understood. While implicated in previous studies as the initiating signals for ALT telomere repair, the prevalence of non-canonical nucleic acid structures in ALT cancers remains unclear. Extending earlier reports, we observe higher levels of DNA/RNA hybrids (R-loops) in ALT-positive (ALT+) compared to telomerase-positive (TERT+) cells. Strikingly, we observe even more pronounced differences for an associated four-stranded nucleic acid structure, G-quadruplex (G4). G4 signals are found at the telomere and are broadly associated with telomere length and accompanied by DNA damage markers. We establish an interdependent relationship between ALT-associated G4s and R-loops and confirm that these two structures can be spatially linked into unique structures, G-loops, at the telomere. Additionally, stabilization of G4s and R-loops cooperatively enhances ALT-activity. However, co-stabilization at higher doses resulted in cytotoxicity in a synergistic manner. Nuclear G4 signals are significantly and reproducibly different between ALT+ and TERT+ low-grade glioma tumours. Together, we present G4 as a novel hallmark of ALT cancers with potential future applications as a convenient biomarker for identifying ALT+ tumours and as therapeutic targets.
RESUMO
The GPN proteins are a conserved family of GTP-binding proteins that are involved in the assembly and subsequent import of RNA polymerase II and III. In this study, we sought to ascertain the specificity of yeast GPN2 for RNA polymerases by screening the localization of a collection of 1350 GFP-tagged nuclear proteins in WT or GPN2 mutant cells. We found that the strongest mislocalization occurred for RNA polymerase II and III subunits and only a handful of other RNAPII associated proteins were altered in GPN2 mutant cells. Our screen identified Ess1, an Rpb1 C-terminal domain (CTD) prolyl isomerase, as mislocalized in GPN2 mutants. Building on this observation we tested for effects of mutations in other factors which regulate Rpb1-CTD phosphorylation status. This uncovered significant changes in nuclear-cytoplasmic distribution of Rpb1-GFP in strains with disrupted RNA polymerase CTD kinases or phosphatases. Overall, this screen shows the exquisite specificity of GPN2 for RNA polymerase transport, and reveals a previously unappreciated role for CTD modification in RNAPII nuclear localization.
Assuntos
Proteínas Monoméricas de Ligação ao GTP , Proteínas de Saccharomyces cerevisiae , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Fosforilação , Proteoma/metabolismo , RNA Polimerase II/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
ARID1A is a core DNA-binding subunit of the BAF chromatin remodeling complex, and is lost in up to 7% of all cancers. The frequency of ARID1A loss increases in certain cancer types, such as clear cell ovarian carcinoma where ARID1A protein is lost in about 50% of cases. While the impact of ARID1A loss on the function of the BAF chromatin remodeling complexes is likely to drive oncogenic gene expression programs in specific contexts, ARID1A also binds genome stability regulators such as ATR and TOP2. Here we show that ARID1A loss leads to DNA replication stress associated with R-loops and transcription-replication conflicts in human cells. These effects correlate with altered transcription and replication dynamics in ARID1A knockout cells and to reduced TOP2A binding at R-loop sites. Together this work extends mechanisms of replication stress in ARID1A deficient cells with implications for targeting ARID1A deficient cancers.
Assuntos
Replicação do DNA/genética , DNA Topoisomerases Tipo II/genética , Proteínas de Ligação a DNA/genética , Neoplasias/genética , Proteínas de Ligação a Poli-ADP-Ribose/genética , Fatores de Transcrição/genética , Proteínas Mutadas de Ataxia Telangiectasia , Montagem e Desmontagem da Cromatina/genética , DNA Helicases/genética , Humanos , Complexos Multiproteicos/genética , Neoplasias/patologia , Proteínas Nucleares/genéticaRESUMO
EFTUD2 is mutated in patients with mandibulofacial dysostosis with microcephaly (MFDM). We generated a mutant mouse line with conditional mutation in Eftud2 and used Wnt1-Cre2 to delete it in neural crest cells. Homozygous deletion of Eftud2 causes brain and craniofacial malformations, affecting the same precursors as in MFDM patients. RNAseq analysis of embryonic heads revealed a significant increase in exon skipping and increased levels of an alternatively spliced Mdm2 transcript lacking exon 3. Exon skipping in Mdm2 was also increased in O9-1 mouse neural crest cells after siRNA knock-down of Eftud2 and in MFDM patient cells. Moreover, we found increased nuclear P53, higher expression of P53-target genes and increased cell death. Finally, overactivation of the P53 pathway in Eftud2 knockdown cells was attenuated by overexpression of non-spliced Mdm2, and craniofacial development was improved when Eftud2-mutant embryos were treated with Pifithrin-α, an inhibitor of P53. Thus, our work indicates that the P53-pathway can be targeted to prevent craniofacial abnormalities and shows a previously unknown role for alternative splicing of Mdm2 in the etiology of MFDM.
Assuntos
Ribonucleoproteína Nuclear Pequena U5 , Proteína Supressora de Tumor p53 , Animais , Homozigoto , Humanos , Camundongos , Mutação , Fatores de Alongamento de Peptídeos/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Ribonucleoproteína Nuclear Pequena U5/genética , Deleção de Sequência , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
DNA replication stress describes a state of impaired replication fork progress that triggers a cellular stress response to maintain genome stability and complete DNA synthesis. Replication stress is a common state that must be tolerated in many cancers. One promising therapeutic approach is targeting replication stress response factors such as the ataxia telangiectasia and rad 3-related kinase (ATR) or checkpoint kinase 1 (CHK1) kinases that some cancers depend upon to survive endogenous replication stress. However, research revealing the complexity of the replication stress response suggests new genetic interactions and candidate therapeutic targets. Many of these candidates regulate DNA transactions around reversed replication forks, including helicases, nucleases and alternative polymerases that promote fork stability and restart. Here we review emerging strategies to exploit replication stress for cancer therapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Reparo do DNA/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dano ao DNA/efeitos dos fármacos , Proteínas de Ligação a DNA/metabolismo , Instabilidade Genômica , Humanos , Neoplasias/genética , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Mutações Sintéticas Letais/efeitos dos fármacosRESUMO
Cdc48 (known as VCP in mammals) is a highly conserved ATPase chaperone that plays an essential role in the assembly and disassembly of protein-DNA complexes and in degradation of misfolded proteins. We find that in Saccharomyces cerevisiae budding yeast, Cdc48 accumulates during cellular stress at intranuclear protein quality control sites (INQ). We show that Cdc48 function is required to suppress INQ formation under non-stress conditions and to promote recovery following genotoxic stress. Cdc48 physically associates with the INQ substrate and splicing factor Hsh155, and regulates its assembly with partner proteins. Accordingly, cdc48 mutants have defects in splicing and show spontaneous distribution of Hsh155 to INQ aggregates, where it is stabilized. Overall, this study shows that Cdc48 regulates deposition of proteins at INQ and suggests a previously unknown role for Cdc48 in the regulation or stabilization of splicing subcomplexes.This article has an associated First Person interview with the first author of the paper.
Assuntos
Ribonucleoproteína Nuclear Pequena U2 , Proteínas de Saccharomyces cerevisiae , Proteína com Valosina , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Fatores de Processamento de RNA , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteína com Valosina/genéticaRESUMO
R loops are three-stranded nucleic acid structures consisting of an RNA molecule that has invaded duplex DNA. R-loop structures have normal functions in regulating gene expression, class-switch recombination, telomere stability, and mitochondrial DNA replication. However, unscheduled R-loop accumulation is a driver of DNA replication stress and genome instability. Meanwhile, R loops and associated transcription-replication conflicts have been observed in cells that have lost tumor-suppressor genes or have activated oncogenes. While ectopic R loops can both disrupt epigenetic states, and promote genome instability, in most cases the hinted-at direct links between R loops and cancer development are lacking. Here, we review the possible influences of altered R-loop stability and metabolism on cancer development and discuss how R-loop accumulation might be exploited to benefit cancer patients.
Assuntos
Predisposição Genética para Doença , Neoplasias/genética , Neoplasias/metabolismo , Estruturas R-Loop , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Dano ao DNA , Replicação do DNA , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Estudos de Associação Genética , Instabilidade Genômica , Histonas/metabolismo , Humanos , Neoplasias/patologia , Neoplasias/terapia , Oncogenes , Processamento de Proteína Pós-Traducional , Transcrição GênicaRESUMO
Ectopic R-loop accumulation causes DNA replication stress and genome instability. To avoid these outcomes, cells possess a range of anti-R-loop mechanisms, including RNaseH that degrades the RNA moiety in R-loops. To comprehensively identify anti-R-loop mechanisms, we performed a genome-wide trigenic interaction screen in yeast lacking RNH1 and RNH201. We identified >100 genes critical for fitness in the absence of RNaseH, which were enriched for DNA replication fork maintenance factors including the MRE11-RAD50-NBS1 (MRN) complex. While MRN has been shown to promote R-loops at DNA double-strand breaks, we show that it suppresses R-loops and associated DNA damage at transcription-replication conflicts. This occurs through a non-nucleolytic function of MRE11 that is important for R-loop suppression by the Fanconi Anemia pathway. This work establishes a novel role for MRE11-RAD50-NBS1 in directing tolerance mechanisms at transcription-replication conflicts.
Assuntos
Hidrolases Anidrido Ácido/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Anemia de Fanconi/metabolismo , Instabilidade Genômica/genética , Proteína Homóloga a MRE11/metabolismo , Proteínas Nucleares/metabolismo , Estruturas R-Loop/genética , Hidrolases Anidrido Ácido/genética , Proteínas de Ciclo Celular/genética , Dano ao DNA/genética , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Anemia de Fanconi/genética , Humanos , Proteína Homóloga a MRE11/genética , Proteínas Nucleares/genética , Ribonuclease H/genética , Schizosaccharomyces/genética , Transcrição Gênica/genéticaRESUMO
The spliceosome has been implicated in genome maintenance for decades. Recently, a surge in discoveries in cancer has suggested that the oncogenic mechanism of spliceosomal defects may involve defective genome stability. The action of the core spliceosome prevents R-loop accumulation, and regulates the expression of genome stability factors. At the same time, specific spliceosomal components have non-canonical functions in genome maintenance. Here we review these different models, highlighting their discovery in different model systems, and describing their potential impact on human disease states.
Assuntos
Processamento Alternativo/genética , Doenças Genéticas Inatas/genética , Genoma Humano/genética , Instabilidade Genômica/genética , Dano ao DNA/genética , Humanos , Mutação , Splicing de RNA/genética , Spliceossomos/genéticaRESUMO
The exosome functions to regulate the cellular transcriptome through RNA biogenesis, surveillance, and decay. Mutations in Dis3, a catalytic subunit of the RNA exosome with separable endonuclease and exonuclease activities, are linked to multiple myeloma. Here we report that a cancer-associated DIS3 allele, dis3E729K, provides evidence for DIS3 functioning in mitotic fidelity in yeast. This dis3E729K allele does not induce defects in 7Sâ5.8S rRNA processing, although it elicits a requirement for P-body function. While it does not significantly influence cell cycle progression alone, the allele reduces the efficiency of cell cycle arrest in strains with defects in kinetochore assembly. Finally, point mutations in the exonuclease domains of yeast Dis3 elicit genome instability phenotypes; however, these DIS3 mutations do not increase DNA damage or RNA processing defects that lead to the accumulation of polyadenylated RNA in the nucleus. These data suggest that specific DIS3 activities support mitotic fidelity in yeast.
Assuntos
Exonucleases/genética , Complexo Multienzimático de Ribonucleases do Exossomo/química , Complexo Multienzimático de Ribonucleases do Exossomo/genética , Instabilidade Genômica/genética , Mutação , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Exonucleases/química , Exonucleases/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Domínios Proteicos/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Chromosomal rearrangements involving the mixed-lineage leukemia (MLL1) gene are common in a unique group of acute leukemias, with more than 100 fusion partners in this malignancy alone. However, do these fusions occur or have a role in solid tumors? We performed extensive network analyses of MLL1-fusion partners in patient datasets, revealing that multiple MLL1-fusion partners exhibited significant interactions with the androgen-receptor signaling pathway. Further exploration of tumor sequence data from TCGA predicts the presence of MLL1 fusions with truncated SET domain in prostate tumors. To investigate the physiological relevance of MLL1 fusions in solid tumors, we engineered a truncated version of MLL1 by fusing it with one of its known fusion partners, ZC3H13, to use as a model system. Functional characterization with cell-based assays revealed that MLL1-ZC3H13 fusion induced chromosomal instability, affected mitotic progression, and enhanced tumorsphere formation. The MLL1-ZC3H13 chimera consistently increased the expression of a cancer stem cell marker (CD44); in addition, we detected potential collateral lethality between DOT1L and MLL1 fusions. Our work reveals that MLL1 fusions are likely prevalent in solid tumors and exhibit a potential pro-tumorigenic role.
Assuntos
Proteínas de Ciclo Celular/genética , Instabilidade Cromossômica/genética , Proteína de Leucina Linfoide-Mieloide/genética , Fusão Oncogênica , Proteínas de Fusão Oncogênica/genética , Proteínas Recombinantes de Fusão/genética , Sequência de Bases , Biomarcadores Tumorais/metabolismo , Carcinogênese/metabolismo , Carcinogênese/patologia , Células Clonais , Redes Reguladoras de Genes , Células HCT116 , Humanos , Modelos Biológicos , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteínas Nucleares , Proteínas de Fusão Oncogênica/metabolismo , Fenótipo , Proteínas de Ligação a RNA , Proteínas Recombinantes de Fusão/metabolismoRESUMO
RNA processing mutants have been broadly implicated in genome stability, but mechanistic links are often unclear. Two predominant models have emerged: one involving changes in gene expression that perturb other genome maintenance factors and another in which genotoxic DNA:RNA hybrids, called R-loops, impair DNA replication. Here we characterize genome instability phenotypes in yeast splicing factor mutants and find that mitotic defects, and in some cases R-loop accumulation, are causes of genome instability. In both cases, alterations in gene expression, rather than direct cis effects, are likely to contribute to instability. Genome instability in splicing mutants is exacerbated by loss of the spindle-assembly checkpoint protein Mad1. Moreover, removal of the intron from the α-tubulin gene TUB1 restores genome integrity. Thus, differing penetrance and selective effects on the transcriptome can lead to a range of phenotypes in conditional mutants of the spliceosome, including multiple routes to genome instability.
Assuntos
Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Instabilidade Genômica , Mutação/genética , Splicing de RNA/genética , Saccharomyces cerevisiae/genética , Cromossomos Fúngicos/genética , Dano ao DNA , Epistasia Genética , Mitose/genética , Fenótipo , Fatores de Processamento de RNA/genética , Fatores de Processamento de RNA/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Spliceossomos/metabolismo , Tubulina (Proteína)/metabolismoRESUMO
Eukaryotic DNA replication occurs in the context of chromatin. Recent years have seen major advances in our understanding of histone supply, histone recycling and nascent histone incorporation during replication. Furthermore, much is now known about the roles of histone remodellers and post-translational modifications in replication. It has also become clear that nucleosome dynamics during replication play critical roles in genome maintenance and that chromatin modifiers are important for preventing DNA replication stress. An understanding of how cells deploy specific nucleosome modifiers, chaperones and remodellers directly at sites of replication fork stalling has been building more slowly. Here we will specifically discuss recent advances in understanding how chromatin composition contribute to replication fork stability and restart.