Suppression of gross chromosomal rearrangements by yKu70-yKu80 heterodimer through DNA damage checkpoints

Abstract Two members of the 14-3-3 protein family, involved in key biological processes in different eukaryotes, are encoded by the functionally redundant Saccharomyces cerevisiae BMH1 and BMH2 genes. We produced and characterized 12 independent bmh1 mutant alleles, whose presence in the cell as the sole 14-3-3 source causes hypersensitivity to genotoxic agents, indicating that Bmh proteins are required for proper response to DNA damage. In particular, the bmh1-103 and bmh1-266 mutant alleles cause defects in G1/S and G2/M DNA damage checkpoints, whereas only the G2/M checkpoint is altered by the bmh1-169 and bmh1-221 alleles. Impaired checkpoint responses correlate with the inability to maintain phosphorylated forms of Rad53 and/or Chk1, suggesting that Bmh proteins might regulate phosphorylation/dephosphorylation of these checkpoint kinases. Moreover, several bmh1 bmh2Δ mutants are defective in resuming DNA replication after transient deoxynucleotide depletion, and all display synthetic effects when also carrying mutations affecting the polα-primase and RPA DNA replication complexes, suggesting a role for Bmh proteins in DNA replication stress response. Finally, the bmh1-169 bmh2Δ and bmh1-170 bmh2Δ mutants show increased rates of spontaneous gross chromosomal rearrangements, indicating that Bmh proteins are required to suppress genome instability.

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The Rad1-Rad10 Complex Promotes the Production of Gross Chromosomal Rearrangements From Spontaneous DNA Damage in Saccharomyces cerevisiae

Genetics ◽

10.1534/genetics.104.039768 ◽

2005 ◽

Vol 169 (4) ◽

pp. 1927-1937 ◽

Cited By ~ 23

Author(s):

Ji-Young Hwang ◽

Stephanie Smith ◽

Kyungjae Myung

Keyword(s):

Saccharomyces Cerevisiae ◽

Dna Damage ◽

Chromosomal Rearrangements ◽

Gross Chromosomal Rearrangements

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Understanding the functions of BRCA1 in the DNA-damage response

Biochemical Society Transactions ◽

10.1042/bst0370597 ◽

2009 ◽

Vol 37 (3) ◽

pp. 597-604 ◽

Cited By ~ 26

Author(s):

Maximina H. Yun ◽

Kevin Hiom

Keyword(s):

Dna Damage ◽

Early Onset ◽

Genome Stability ◽

Chromosomal Rearrangements ◽

Dna Lesions ◽

Cell Cycle Checkpoints ◽

Dna Breaks ◽

Gross Chromosomal Rearrangements ◽

Damage Response ◽

Regulation Of Cell Cycle

Inheritance of a mutation in BRCA1 (breast cancer 1 early-onset) results in predisposition to early-onset breast and ovarian cancer. Tumours in these individuals arise after somatic mutation or loss of the wild-type allele. Loss of BRCA1 function leads to a profound increase in genomic instability involving the accumulation of mutations, DNA breaks and gross chromosomal rearrangements. Accordingly, BRCA1 has been implicated as an important factor involved in both the repair of DNA lesions and in the regulation of cell-cycle checkpoints in response to DNA damage. However, the molecular mechanism through which BRCA1 functions to preserve genome stability remains unclear. In the present article, we examine the different ways in which BRCA1 might influence the repair of DNA damage and the preservation of genome integrity, taking into account what is currently known about its interactions with other proteins, its biochemical activity and its nuclear localization.

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Inactivation of folylpolyglutamate synthetase Met7 results in genome instability driven by an increased dUTP/dTTP ratio

Nucleic Acids Research ◽

10.1093/nar/gkz1006 ◽

2019 ◽

Author(s):

Tobias T Schmidt ◽

Sushma Sharma ◽

Gloria X Reyes ◽

Anna Kolodziejczak ◽

Tina Wagner ◽

...

Keyword(s):

Dna Damage ◽

Genome Stability ◽

Nuclear Dna ◽

Genome Instability ◽

Chromosomal Rearrangements ◽

Dna Integrity ◽

Folylpolyglutamate Synthetase ◽

Cell Extracts ◽

Gross Chromosomal Rearrangements ◽

The Stability

Abstract The accumulation of mutations is frequently associated with alterations in gene function leading to the onset of diseases, including cancer. Aiming to find novel genes that contribute to the stability of the genome, we screened the Saccharomyces cerevisiae deletion collection for increased mutator phenotypes. Among the identified genes, we discovered MET7, which encodes folylpolyglutamate synthetase (FPGS), an enzyme that facilitates several folate-dependent reactions including the synthesis of purines, thymidylate (dTMP) and DNA methylation. Here, we found that Met7-deficient strains show elevated mutation rates, but also increased levels of endogenous DNA damage resulting in gross chromosomal rearrangements (GCRs). Quantification of deoxyribonucleotide (dNTP) pools in cell extracts from met7Δ mutant revealed reductions in dTTP and dGTP that cause a constitutively active DNA damage checkpoint. In addition, we found that the absence of Met7 leads to dUTP accumulation, at levels that allowed its detection in yeast extracts for the first time. Consequently, a high dUTP/dTTP ratio promotes uracil incorporation into DNA, followed by futile repair cycles that compromise both mitochondrial and nuclear DNA integrity. In summary, this work highlights the importance of folate polyglutamylation in the maintenance of nucleotide homeostasis and genome stability.

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Shared and distinct roles of Esc2 and Mms21 in suppressing genome rearrangements and regulating intracellular sumoylation

PLoS ONE ◽

10.1371/journal.pone.0247132 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0247132

Author(s):

Raymond T. Suhandynata ◽

Yong-Qi Gao ◽

Ann L. Zhou ◽

Yusheng Yang ◽

Pang-Che Wang ◽

...

Keyword(s):

Dna Damage ◽

Chromosomal Rearrangements ◽

Dna Helicase ◽

Growth Defect ◽

Catalytic Core ◽

E3 Ligases ◽

Nucleolar Proteins ◽

Gross Chromosomal Rearrangements ◽

Mcm Complex ◽

Sumo E3 Ligase

Protein sumoylation, especially when catalyzed by the Mms21 SUMO E3 ligase, plays a major role in suppressing duplication-mediated gross chromosomal rearrangements (dGCRs). How Mms21 targets its substrates in the cell is insufficiently understood. Here, we demonstrate that Esc2, a protein with SUMO-like domains (SLDs), recruits the Ubc9 SUMO conjugating enzyme to specifically facilitate Mms21-dependent sumoylation and suppress dGCRs. The D430R mutation in Esc2 impairs its binding to Ubc9 and causes a synergistic growth defect and accumulation of dGCRs with mutations that delete the Siz1 and Siz2 E3 ligases. By contrast, esc2-D430R does not appreciably affect sensitivity to DNA damage or the dGCRs caused by the catalytically inactive mms21-CH. Moreover, proteome-wide analysis of intracellular sumoylation demonstrates that esc2-D430R specifically down-regulates sumoylation levels of Mms21-preferred targets, including the nucleolar proteins, components of the SMC complexes and the MCM complex that acts as the catalytic core of the replicative DNA helicase. These effects closely resemble those caused by mms21-CH, and are relatively unaffected by deleting Siz1 and Siz2. Thus, by recruiting Ubc9, Esc2 facilitates Mms21-dependent sumoylation to suppress the accumulation of dGCRs independent of Siz1 and Siz2.

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Gross chromosomal rearrangements and genetic exchange between nonhomologous chromosomes following BRCA2 inactivation

Genes & Development ◽

10.1101/gad.14.11.1400 ◽

2000 ◽

Vol 14 (11) ◽

pp. 1400-1406 ◽

Cited By ~ 1

Author(s):

Veronica P.C.C. Yu ◽

Michael Koehler ◽

Claus Steinlein ◽

Michael Schmid ◽

Leslyn A. Hanakahi ◽

...

Keyword(s):

Dna Damage ◽

Genetic Instability ◽

Genomic Dna ◽

Chromosomal Rearrangements ◽

Chromosome Breakage ◽

Genetic Exchange ◽

Dna Breaks ◽

Gross Chromosomal Rearrangements ◽

Essential Function ◽

Mechanistic Basis

Cancer-causing mutations often arise from gross chromosomal rearrangements (GCRs) such as translocations, which involve genetic exchange between nonhomologous chromosomes. Here we show that murineBrca2 has an essential function in suppressing GCR formation after chromosome breakage. Cells that harbor truncated Brca2spontaneously incur GCRs and genomic DNA breaks during division. They exhibit hypersensitivity to DNA damage by interstrand cross-linkers, which even at low doses trigger aberrant genetic exchange between nonhomologous chromosomes. Therefore, genetic instability in Brca2-deficient cells results from the mutagenic processing of spontaneous or induced DNA damage into gross chromosomal rearrangements, providing a mechanistic basis for cancer predisposition.

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Cdc28/Cdk1 positively and negatively affects genome stability in S. cerevisiae

The Journal of Cell Biology ◽

10.1083/jcb.200811083 ◽

2009 ◽

Vol 185 (3) ◽

pp. 423-437 ◽

Cited By ~ 28

Author(s):

Jorrit M. Enserink ◽

Hans Hombauer ◽

Meng-Er Huang ◽

Richard D. Kolodner

Keyword(s):

Dna Damage ◽

Cell Viability ◽

Genome Stability ◽

Chromosomal Rearrangements ◽

Genetic Network ◽

Telomere Maintenance ◽

Mitotic Catastrophe ◽

Chemical Genetic ◽

Replication Arrest ◽

Gross Chromosomal Rearrangements

We studied the function of the cyclin-dependent kinase Cdc28 (Cdk1) in the DNA damage response and maintenance of genome stability using Saccharomyces cerevisiae. Reduced Cdc28 activity sensitizes cells to chronic DNA damage, but Cdc28 is not required for cell viability upon acute exposure to DNA-damaging agents. Cdc28 is also not required for activation of the DNA damage and replication checkpoints. Chemical–genetic analysis reveals that CDC28 functions in an extensive network of pathways involved in maintenance of genome stability, including homologous recombination, sister chromatid cohesion, the spindle checkpoint, postreplication repair, and telomere maintenance. In addition, Cdc28 and Mre11 appear to cooperate to prevent mitotic catastrophe after DNA replication arrest. We show that reduced Cdc28 activity results in suppression of gross chromosomal rearrangements (GCRs), indicating that Cdc28 is required for formation or recovery of GCRs. Thus, we conclude that Cdc28 functions in a genetic network that supports cell viability during DNA damage while promoting the formation of GCRs.

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Oncogene homologue Sch9 promotes age-dependent mutations by a superoxide and Rev1/Polζ-dependent mechanism

The Journal of Cell Biology ◽

10.1083/jcb.200906011 ◽

2009 ◽

Vol 186 (4) ◽

pp. 509-523 ◽

Cited By ~ 49

Author(s):

Federica Madia ◽

Min Wei ◽

Valerie Yuan ◽

Jia Hu ◽

Cristina Gattazzo ◽

...

Keyword(s):

Dna Damage ◽

Chromosomal Rearrangements ◽

Point Mutations ◽

Mitochondrial Superoxide ◽

Gross Chromosomal Rearrangements ◽

Age Dependent ◽

Induced Mutagenesis ◽

Major Increase ◽

Oncogene Homologue ◽

Mitochondrial Superoxide Dismutase

Oncogenes contribute to tumorigenesis by promoting growth and inhibiting apoptosis. Here we examine the function of Sch9, the Saccharomyces cerevisiae homologue of the mammalian Akt and S6 kinase, in DNA damage and genomic instability during aging in nondividing cells. Attenuation of age-dependent increases in base substitutions, small DNA insertions/deletions, and gross chromosomal rearrangements (GCRs) in sch9Δ mutants is associated with increased mitochondrial superoxide dismutase (MnSOD) expression, decreased DNA oxidation, reduced REV1 expression and translesion synthesis, and elevated resistance to oxidative stress-induced mutagenesis. Deletion of REV1, the lack of components of the error-prone Polζ, or the overexpression of SOD1 or SOD2 is sufficient to reduce age-dependent point mutations in SCH9 overexpressors, but REV1 deficiency causes a major increase in GCRs. These results suggest that the proto-oncogene homologue Sch9 promotes the accumulation of superoxide-dependent DNA damage in nondividing cells, which induces error-prone DNA repair that generates point mutations to avoid GCRs and cell death during the first round of replication.

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Overlapping Roles of the Spindle Assembly and DNA Damage Checkpoints in the Cell-Cycle Response to Altered Chromosomes in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/161.2.521 ◽

2002 ◽

Vol 161 (2) ◽

pp. 521-534

Author(s):

Peter M Garber ◽

Jasper Rine

Keyword(s):

Dna Damage ◽

Dna Replication ◽

Spindle Checkpoint ◽

Dna Lesions ◽

Replication Proteins ◽

Replication Checkpoint ◽

Dna Damage Checkpoints ◽

Dna Replication Checkpoint ◽

Mcm Proteins ◽

Stalled Replication Forks

Abstract The MAD2-dependent spindle checkpoint blocks anaphase until all chromosomes have achieved successful bipolar attachment to the mitotic spindle. The DNA damage and DNA replication checkpoints block anaphase in response to DNA lesions that may include single-stranded DNA and stalled replication forks. Many of the same conditions that activate the DNA damage and DNA replication checkpoints also activated the spindle checkpoint. The mad2Δ mutation partially relieved the arrest responses of cells to mutations affecting the replication proteins Mcm3p and Pol1p. Thus a previously unrecognized aspect of spindle checkpoint function may be to protect cells from defects in DNA replication. Furthermore, in cells lacking either the DNA damage or the DNA replication checkpoints, the spindle checkpoint contributed to the arrest responses of cells to the DNA-damaging agent methyl methanesulfonate, the replication inhibitor hydroxyurea, and mutations affecting Mcm2p and Orc2p. Thus the spindle checkpoint was sensitive to a wider range of chromosomal perturbations than previously recognized. Finally, the DNA replication checkpoint did not contribute to the arrests of cells in response to mutations affecting ORC, Mcm proteins, or DNA polymerase δ. Thus the specificity of this checkpoint may be more limited than previously recognized.

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SINE-B1 Distribution and Chromosome Rearrangements in the South American Proechimys gr. goeldii (Echimyidae, Rodentia)

Cytogenetic and Genome Research ◽

10.1159/000513106 ◽

2021 ◽

pp. 1-8

Author(s):

Naiara P. Araújo ◽

Radarane S. Sena ◽

Cibele R. Bonvicino ◽

Gustavo C.S. Kuhn ◽

Marta Svartman

Keyword(s):

Transposable Element ◽

Genome Evolution ◽

Significant Role ◽

Sex Chromosomes ◽

Chromosomal Rearrangements ◽

Evolutionary Relationship ◽

Chromosome Rearrangements ◽

South American ◽

Gross Chromosomal Rearrangements

Proechimys species are remarkable for their extensive chromosome rearrangements, representing a good model to understand genome evolution. Herein, we cytogenetically analyzed 3 different cytotypes of Proechimys gr. goeldii to assess their evolutionary relationship. We also mapped the transposable element SINE-B1 on the chromosomes of P. gr. goeldii in order to investigate its distribution among individuals and evaluate its possible contribution to karyotype remodeling in this species. SINE-B1 showed a dispersed distribution along chromosome arms and was also detected at the pericentromeric regions of some chromosomes, including pair 1 and the sex chromosomes, which are involved in chromosome rearrangements. In addition, we describe a new cytotype for P. gr. goeldii, reinforcing the significant role of gross chromosomal rearrangements during the evolution of the genus. The results of FISH with SINE-B1 suggest that this issue should be more deeply investigated for a better understanding of its role in the mechanisms involved in the wide variety of Proechimys karyotypes.

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