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Involvement of the Cohesin Cofactor PDS5 (SPO76) During Meiosis and DNA Repair in Arabidopsis thaliana.

Pradillo M, Knoll A, Oliver C, Varas J, Corredor E, Puchta H, Santos JL - Front Plant Sci (2015)

Bottom Line: Cohesin cofactors contribute to cohesin dynamics and interact with cohesin complexes during cell cycle.In Arabidopsis, AtWAPL proteins are essential during meiosis, however, the role of AtPDS5 remains to be ascertained.Furthermore, this cohesin cofactor could be important for the function of the AtSMC5/AtSMC6 complex.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Genética, Facultad de Biología, Universidad Complutense Madrid, Spain.

ABSTRACT
Maintenance and precise regulation of sister chromatid cohesion is essential for faithful chromosome segregation during mitosis and meiosis. Cohesin cofactors contribute to cohesin dynamics and interact with cohesin complexes during cell cycle. One of these, PDS5, also known as SPO76, is essential during mitosis and meiosis in several organisms and also plays a role in DNA repair. In yeast, the complex Wapl-Pds5 controls cohesion maintenance and colocalizes with cohesin complexes into chromosomes. In Arabidopsis, AtWAPL proteins are essential during meiosis, however, the role of AtPDS5 remains to be ascertained. Here we have isolated mutants for each of the five AtPDS5 genes (A-E) and obtained, after different crosses between them, double, triple, and even quadruple mutants (Atpds5a Atpds5b Atpds5c Atpds5e). Depletion of AtPDS5 proteins has a weak impact on meiosis, but leads to severe effects on development, fertility, somatic homologous recombination (HR) and DNA repair. Furthermore, this cohesin cofactor could be important for the function of the AtSMC5/AtSMC6 complex. Contrarily to its function in other species, our results suggest that AtPDS5 is dispensable during the meiotic division of Arabidopsis, although it plays an important role in DNA repair by HR.

No MeSH data available.


Related in: MedlinePlus

Atpds5 double, triple, and quadruple mutants are hypersensitive to γ-rays. (A) Phenotypes of 14-day-old seedlings (WT, double, triple, and quadruple mutants) after treatment with different radiation doses. (B) Mean number of true leaves per plant after treatment with different radiation doses. Mean values and standard errors are depicted. Asterisks indicate p-values from t-Student tests: NS, not significant; ∗∗∗p < 0.001, ∗∗p < 0.01, and ∗p < 0.05. ab: Atpds5a Atpds5b; abc: Atpds5a Atpds5b Atpds5c; abce: Atpds5a Atpds5b Atpds5c Atpds5e.
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Figure 4: Atpds5 double, triple, and quadruple mutants are hypersensitive to γ-rays. (A) Phenotypes of 14-day-old seedlings (WT, double, triple, and quadruple mutants) after treatment with different radiation doses. (B) Mean number of true leaves per plant after treatment with different radiation doses. Mean values and standard errors are depicted. Asterisks indicate p-values from t-Student tests: NS, not significant; ∗∗∗p < 0.001, ∗∗p < 0.01, and ∗p < 0.05. ab: Atpds5a Atpds5b; abc: Atpds5a Atpds5b Atpds5c; abce: Atpds5a Atpds5b Atpds5c Atpds5e.

Mentions: Many proteins involved in sister chromatid cohesion are important for the maintenance of genome integrity and repair of DNA damage during the cell cycle (da Costa-Nunes et al., 2006; Bolaños-Villegas et al., 2013). To assess whether AtPDS5 plays a similar role, we tested Atpds5 mutants for hypersensitivity to γ-irradiation, a DSB-inducing agent, and the CL agents MMC, which mainly produces inter-strand CLs (Rink et al., 1996), and CDDP, which preferentially forms intra-strand CLs (Eastman, 1985; Boulikas and Vougiouka, 2003). Although both types of CL agents induce partially different types of DNA damage, both are expected to create DSBs during DNA synthesis, which are mostly repaired by HR. A hypersensitive response to γ-rays was consistently observed in the double, triple and quadruple mutants when compared with WT (Figure 4). Triple and quadruple mutants also showed hypersensitivity to MMC (Supplementary Figure S6). Finally, only the quadruple mutant revealed higher sensitivity than WT to high CDDP doses (Supplementary Figure S7). The global assessment of these results indicates that the quadruple mutant is more sensitive to DNA damage than the triple mutant, which in turn is more sensitive than the double mutant. Therefore, AtPDS5 genes are involved in DNA damage response and the function of the different AtPDS5 genes in DSB repair seems to be non-redundant.


Involvement of the Cohesin Cofactor PDS5 (SPO76) During Meiosis and DNA Repair in Arabidopsis thaliana.

Pradillo M, Knoll A, Oliver C, Varas J, Corredor E, Puchta H, Santos JL - Front Plant Sci (2015)

Atpds5 double, triple, and quadruple mutants are hypersensitive to γ-rays. (A) Phenotypes of 14-day-old seedlings (WT, double, triple, and quadruple mutants) after treatment with different radiation doses. (B) Mean number of true leaves per plant after treatment with different radiation doses. Mean values and standard errors are depicted. Asterisks indicate p-values from t-Student tests: NS, not significant; ∗∗∗p < 0.001, ∗∗p < 0.01, and ∗p < 0.05. ab: Atpds5a Atpds5b; abc: Atpds5a Atpds5b Atpds5c; abce: Atpds5a Atpds5b Atpds5c Atpds5e.
© Copyright Policy
Related In: Results  -  Collection

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Figure 4: Atpds5 double, triple, and quadruple mutants are hypersensitive to γ-rays. (A) Phenotypes of 14-day-old seedlings (WT, double, triple, and quadruple mutants) after treatment with different radiation doses. (B) Mean number of true leaves per plant after treatment with different radiation doses. Mean values and standard errors are depicted. Asterisks indicate p-values from t-Student tests: NS, not significant; ∗∗∗p < 0.001, ∗∗p < 0.01, and ∗p < 0.05. ab: Atpds5a Atpds5b; abc: Atpds5a Atpds5b Atpds5c; abce: Atpds5a Atpds5b Atpds5c Atpds5e.
Mentions: Many proteins involved in sister chromatid cohesion are important for the maintenance of genome integrity and repair of DNA damage during the cell cycle (da Costa-Nunes et al., 2006; Bolaños-Villegas et al., 2013). To assess whether AtPDS5 plays a similar role, we tested Atpds5 mutants for hypersensitivity to γ-irradiation, a DSB-inducing agent, and the CL agents MMC, which mainly produces inter-strand CLs (Rink et al., 1996), and CDDP, which preferentially forms intra-strand CLs (Eastman, 1985; Boulikas and Vougiouka, 2003). Although both types of CL agents induce partially different types of DNA damage, both are expected to create DSBs during DNA synthesis, which are mostly repaired by HR. A hypersensitive response to γ-rays was consistently observed in the double, triple and quadruple mutants when compared with WT (Figure 4). Triple and quadruple mutants also showed hypersensitivity to MMC (Supplementary Figure S6). Finally, only the quadruple mutant revealed higher sensitivity than WT to high CDDP doses (Supplementary Figure S7). The global assessment of these results indicates that the quadruple mutant is more sensitive to DNA damage than the triple mutant, which in turn is more sensitive than the double mutant. Therefore, AtPDS5 genes are involved in DNA damage response and the function of the different AtPDS5 genes in DSB repair seems to be non-redundant.

Bottom Line: Cohesin cofactors contribute to cohesin dynamics and interact with cohesin complexes during cell cycle.In Arabidopsis, AtWAPL proteins are essential during meiosis, however, the role of AtPDS5 remains to be ascertained.Furthermore, this cohesin cofactor could be important for the function of the AtSMC5/AtSMC6 complex.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Genética, Facultad de Biología, Universidad Complutense Madrid, Spain.

ABSTRACT
Maintenance and precise regulation of sister chromatid cohesion is essential for faithful chromosome segregation during mitosis and meiosis. Cohesin cofactors contribute to cohesin dynamics and interact with cohesin complexes during cell cycle. One of these, PDS5, also known as SPO76, is essential during mitosis and meiosis in several organisms and also plays a role in DNA repair. In yeast, the complex Wapl-Pds5 controls cohesion maintenance and colocalizes with cohesin complexes into chromosomes. In Arabidopsis, AtWAPL proteins are essential during meiosis, however, the role of AtPDS5 remains to be ascertained. Here we have isolated mutants for each of the five AtPDS5 genes (A-E) and obtained, after different crosses between them, double, triple, and even quadruple mutants (Atpds5a Atpds5b Atpds5c Atpds5e). Depletion of AtPDS5 proteins has a weak impact on meiosis, but leads to severe effects on development, fertility, somatic homologous recombination (HR) and DNA repair. Furthermore, this cohesin cofactor could be important for the function of the AtSMC5/AtSMC6 complex. Contrarily to its function in other species, our results suggest that AtPDS5 is dispensable during the meiotic division of Arabidopsis, although it plays an important role in DNA repair by HR.

No MeSH data available.


Related in: MedlinePlus