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Functions of Fun30 chromatin remodeler in regulating cellular resistance to genotoxic stress.

Bi X, Yu Q, Siler J, Li C, Khan A - PLoS ONE (2015)

Bottom Line: We further show that Fun30 negatively regulates the recovery of rad5Δ mutant from MMS induced G2/M arrest.The latter becomes manifest when Rad5 dependent DNA damage tolerance is impaired.In addition, we find that the putative ubiquitin-binding CUE domain of Fun30 serves to restrict the ability of Fun30 to hinder MMS- and HU-tolerance in the absence of Rad5.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Rochester, Rochester, New York, United States of America.

ABSTRACT
The Saccharomyces cerevisiae Fun30 chromatin remodeler has recently been shown to facilitate long-range resection of DNA double strand break (DSB) ends, which proceeds homologous recombination (HR). This is believed to underlie the role of Fun30 in promoting cellular resistance to DSB inducing agent camptothecin. We show here that Fun30 also contributes to cellular resistance to genotoxins methyl methanesulfonate (MMS) and hydroxyurea (HU) that can stall the progression of DNA replication. We present evidence implicating DNA end resection in Fun30-dependent MMS-resistance. On the other hand, we show that Fun30 deletion suppresses the MMS- and HU-sensitivity of cells lacking the Rad5/Mms2/Ubc13-dependent error-free DNA damage tolerance mechanism. This suppression is not the result of a reduction in DNA end resection, and is dependent on the key HR component Rad51. We further show that Fun30 negatively regulates the recovery of rad5Δ mutant from MMS induced G2/M arrest. Therefore, Fun30 has two functions in DNA damage repair: one is the promotion of cellular resistance to genotoxic stress by aiding in DNA end resection, and the other is the negative regulation of a Rad51-dependent, DNA end resection-independent mechanism for countering replicative stress. The latter becomes manifest when Rad5 dependent DNA damage tolerance is impaired. In addition, we find that the putative ubiquitin-binding CUE domain of Fun30 serves to restrict the ability of Fun30 to hinder MMS- and HU-tolerance in the absence of Rad5.

No MeSH data available.


Related in: MedlinePlus

Fun30 contributes to cellular tolerance to genotoxins MMS, HU and CPT.Shown are growth phenotypes of strains 1–12 (S1 Table) on indicated media. Strains bearing the rad5-535 mutation are marked with asterisks. Cells were grown to late log phase and serial 10-fold dilutions were spotted on SC (synthetic complete medium) with or without MMS, HU or CPT. The plates were incubated for 3 days unless otherwise indicated.
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pone.0121341.g001: Fun30 contributes to cellular tolerance to genotoxins MMS, HU and CPT.Shown are growth phenotypes of strains 1–12 (S1 Table) on indicated media. Strains bearing the rad5-535 mutation are marked with asterisks. Cells were grown to late log phase and serial 10-fold dilutions were spotted on SC (synthetic complete medium) with or without MMS, HU or CPT. The plates were incubated for 3 days unless otherwise indicated.

Mentions: We reexamined whether Fun30 plays roles in cellular resistance to MMS and HU by monitoring the effect of fun30Δ on the growth of a series of strains derived originally from S228c or W303 in the presence of different dosages of MMS or HU. We found that fun30Δ decreased the resistance to HU (at a relatively high concentration of 150 mM or 200 mM) of all strains (Fig. 1A, compare strains 2, 4, 6, 8 with 1, 3, 5, and 7, respectively, on HU-containing medium). However, surprisingly, fun30Δ appeared to have varying effects on MMS resistance depending on the strains tested. Specifically, fun30Δ made strains BY4741 and YQY726 more sensitive to MMS, but rendered CCFY101 and ZGY005 more resistant to MMS at a relatively high concentration (0.01%) (Fig. 1A, compare strains 2, 4, 6, 8 with 1, 3, 5, and 7, respectively on MMS-containing medium). We noticed that BY4741 and YQY726 were generally more resistant to MMS than CCFY101 and ZGY005 (Fig. 1A). These results demonstrated again that the genetic background of a strain may affect its sensitivity to genotoxins, and may even determine if a factor plays a positive or negative role in DNA damage response. Consistent with previous studies, we found that fun30Δ reduced cellular tolerance to CPT to various degrees in all strains tested (Fig. 1A).


Functions of Fun30 chromatin remodeler in regulating cellular resistance to genotoxic stress.

Bi X, Yu Q, Siler J, Li C, Khan A - PLoS ONE (2015)

Fun30 contributes to cellular tolerance to genotoxins MMS, HU and CPT.Shown are growth phenotypes of strains 1–12 (S1 Table) on indicated media. Strains bearing the rad5-535 mutation are marked with asterisks. Cells were grown to late log phase and serial 10-fold dilutions were spotted on SC (synthetic complete medium) with or without MMS, HU or CPT. The plates were incubated for 3 days unless otherwise indicated.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4373758&req=5

pone.0121341.g001: Fun30 contributes to cellular tolerance to genotoxins MMS, HU and CPT.Shown are growth phenotypes of strains 1–12 (S1 Table) on indicated media. Strains bearing the rad5-535 mutation are marked with asterisks. Cells were grown to late log phase and serial 10-fold dilutions were spotted on SC (synthetic complete medium) with or without MMS, HU or CPT. The plates were incubated for 3 days unless otherwise indicated.
Mentions: We reexamined whether Fun30 plays roles in cellular resistance to MMS and HU by monitoring the effect of fun30Δ on the growth of a series of strains derived originally from S228c or W303 in the presence of different dosages of MMS or HU. We found that fun30Δ decreased the resistance to HU (at a relatively high concentration of 150 mM or 200 mM) of all strains (Fig. 1A, compare strains 2, 4, 6, 8 with 1, 3, 5, and 7, respectively, on HU-containing medium). However, surprisingly, fun30Δ appeared to have varying effects on MMS resistance depending on the strains tested. Specifically, fun30Δ made strains BY4741 and YQY726 more sensitive to MMS, but rendered CCFY101 and ZGY005 more resistant to MMS at a relatively high concentration (0.01%) (Fig. 1A, compare strains 2, 4, 6, 8 with 1, 3, 5, and 7, respectively on MMS-containing medium). We noticed that BY4741 and YQY726 were generally more resistant to MMS than CCFY101 and ZGY005 (Fig. 1A). These results demonstrated again that the genetic background of a strain may affect its sensitivity to genotoxins, and may even determine if a factor plays a positive or negative role in DNA damage response. Consistent with previous studies, we found that fun30Δ reduced cellular tolerance to CPT to various degrees in all strains tested (Fig. 1A).

Bottom Line: We further show that Fun30 negatively regulates the recovery of rad5Δ mutant from MMS induced G2/M arrest.The latter becomes manifest when Rad5 dependent DNA damage tolerance is impaired.In addition, we find that the putative ubiquitin-binding CUE domain of Fun30 serves to restrict the ability of Fun30 to hinder MMS- and HU-tolerance in the absence of Rad5.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Rochester, Rochester, New York, United States of America.

ABSTRACT
The Saccharomyces cerevisiae Fun30 chromatin remodeler has recently been shown to facilitate long-range resection of DNA double strand break (DSB) ends, which proceeds homologous recombination (HR). This is believed to underlie the role of Fun30 in promoting cellular resistance to DSB inducing agent camptothecin. We show here that Fun30 also contributes to cellular resistance to genotoxins methyl methanesulfonate (MMS) and hydroxyurea (HU) that can stall the progression of DNA replication. We present evidence implicating DNA end resection in Fun30-dependent MMS-resistance. On the other hand, we show that Fun30 deletion suppresses the MMS- and HU-sensitivity of cells lacking the Rad5/Mms2/Ubc13-dependent error-free DNA damage tolerance mechanism. This suppression is not the result of a reduction in DNA end resection, and is dependent on the key HR component Rad51. We further show that Fun30 negatively regulates the recovery of rad5Δ mutant from MMS induced G2/M arrest. Therefore, Fun30 has two functions in DNA damage repair: one is the promotion of cellular resistance to genotoxic stress by aiding in DNA end resection, and the other is the negative regulation of a Rad51-dependent, DNA end resection-independent mechanism for countering replicative stress. The latter becomes manifest when Rad5 dependent DNA damage tolerance is impaired. In addition, we find that the putative ubiquitin-binding CUE domain of Fun30 serves to restrict the ability of Fun30 to hinder MMS- and HU-tolerance in the absence of Rad5.

No MeSH data available.


Related in: MedlinePlus