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Mitsuhiro Yanagida - One of the best experts on this subject based on the ideXlab platform.
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Suppressor mutation analysis combined with 3D modeling explains cohesin's capacity to hold and release DNA.
Proceedings of the National Academy of Sciences of the United States of America, 2018Co-Authors: Ryuta Kanai, Norihiko Nakazawa, Li Wang, Chikashi Toyoshima, Mitsuhiro YanagidaAbstract:Cohesin is a fundamental protein complex that holds sister chromatids together. Separase protease cleaves a cohesin subunit RAD21/SCC1, causing the release of cohesin from DNA to allow chromosome segregation. To understand the functional organization of cohesin, we employed next-generation whole-genome sequencing and identified numerous extragenic suppressors that overcome either inactive separase/Cut1 or defective cohesin in the fission yeast Schizosaccharomyces pombe Unexpectedly, Cut1 is dispensable if suppressor mutations cause disorders of interfaces among essential cohesin subunits Psm1/SMC1, Psm3/SMC3, RAD21/SCC1, and Mis4/SCC2, the crystal structures of which suggest physical and functional impairment at the interfaces of Psm1/3 hinge, Psm1 head-RAD21, or Psm3 coiled coil-RAD21. Molecular-dynamics analysis indicates that the intermolecular β-sheets in the cohesin hinge of cut1 suppressor mutants remain intact, but a large mobility change occurs at the coiled coil bound to the hinge. In contrast, suppressors of RAD21-K1 occur in either the head ATPase domains or the Psm3 coiled coil that interacts with RAD21. Suppressors of mis4-G1326E reside in the head of Psm3/1 or the intragenic domain of Mis4. These may restore the binding of cohesin to DNA. Evidence is provided that the head and hinge of SMC subunits are proximal, and that they coordinate to form arched coils that can hold or release DNA by altering the angles made by the arched coiled coils. By combining molecular modeling with suppressor sequence analysis, we propose a cohesin structure designated the "hold-and-release" model, which may be considered as an alternative to the prevailing "ring" model.
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cut1 separase dependent roles of multiple phosphorylation of fission yeast cohesion subunit RAD21 in post replicative damage repair and mitosis
Cell Cycle, 2008Co-Authors: Yoh Adachi, Koji Nagao, Aya Kokubu, Masahiro Ebe, Mitsuhiro YanagidaAbstract:Cohesin is a multiprotein complex essential for sister-chromatid cohesion. It plays a pivotal role in proper chromosome segregation and DNA damage repair. The mitotic behavior of cohesin is controlled through its phosphorylation, which possibly induces the dissociation of cohesin from chromosomes and enhances its susceptibility to separase. Here, we report using mass spectrometry and anti-phospho antibodies that the central domain of RAD21, the separase-target subunit of Schizosaccharomyces pombe cohesin, is regulated by various kinase-induced phosphorylation at nine residues, indicating the multiple roles for S. pombe cohesin. In vegetative and non-dividing G(0) cells, RAD21 is phosphorylated by unknown S/TP-consensus kinases, in mitotic and non-mitotic cells by polo/Plo1 and CDK, and in DNA-damaged cells by Rad3/ATR. While mitotic phosphorylation is implicated in the dissociation of RAD21 and its cleavage by separase in anaphase, the Rad3/ATR-dependent damage-induced phosphorylation occurs intensively at the time of repair completion, and only in post-replicative cells. This damage-induced RAD21 phosphorylation is involved in the recovery process of cells from checkpoint arrest, and needed for the removal of cohesin by separase after the completion of damage repair. These complex phospho-regulations of RAD21 indicate the functional significance of cohesin in cell adaptation to a variety of cellular conditions.
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Cut1/separase-dependent roles of multiple phosphorylation of fission yeast cohesion subunit RAD21 in post-replicative damage repair and mitosis.
Cell cycle (Georgetown Tex.), 2007Co-Authors: Yoh Adachi, Koji Nagao, Aya Kokubu, Masahiro Ebe, Mitsuhiro YanagidaAbstract:Cohesin is a multiprotein complex essential for sister-chromatid cohesion. It plays a pivotal role in proper chromosome segregation and DNA damage repair. The mitotic behavior of cohesin is controlled through its phosphorylation, which possibly induces the dissociation of cohesin from chromosomes and enhances its susceptibility to separase. Here, we report using mass spectrometry and anti-phospho antibodies that the central domain of RAD21, the separase-target subunit of Schizosaccharomyces pombe cohesin, is regulated by various kinase-induced phosphorylation at nine residues, indicating the multiple roles for S. pombe cohesin. In vegetative and non-dividing G(0) cells, RAD21 is phosphorylated by unknown S/TP-consensus kinases, in mitotic and non-mitotic cells by polo/Plo1 and CDK, and in DNA-damaged cells by Rad3/ATR. While mitotic phosphorylation is implicated in the dissociation of RAD21 and its cleavage by separase in anaphase, the Rad3/ATR-dependent damage-induced phosphorylation occurs intensively at the time of repair completion, and only in post-replicative cells. This damage-induced RAD21 phosphorylation is involved in the recovery process of cells from checkpoint arrest, and needed for the removal of cohesin by separase after the completion of damage repair. These complex phospho-regulations of RAD21 indicate the functional significance of cohesin in cell adaptation to a variety of cellular conditions.
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Requirement of chromatid cohesion proteins RAD21/scc1 and mis4/scc2 for normal spindle-kinetochore interaction in fission yeast.
Current biology : CB, 2002Co-Authors: Yusuke Toyoda, Koji Nagao, Kanji Furuya, Gohta Goshima, Kohta Takahashi, Mitsuhiro YanagidaAbstract:Proteins conserved from yeast to human hold two sister chromatids together. The failure to form cohesion in the S phase results in premature separation of chromatids in G2/M. Mitotic kinetochores free from microtubules or the lack of tension are known to activate spindle checkpoint. The loss of chromatid cohesion in fission yeast mutants (mis4-242 and RAD21-K1) leads to the activation of Mad2- and Bub1-dependent checkpoint, possibly due to a diminished microtubule-kinetochore interaction. Bub1, a checkpoint kinase, localizes briefly at early mitotic kinetochores in wild-type, whereas the cohesion mutation greatly increases the duration of kinetochore localization. Bub1 is bound to the central centromere region of mitotic cells. These cohesion mutants are hypersensitive to a tubulin poison and are synthetic lethal with dis1 and bir1/cut17, which are defective in microtubule-kinetochore interaction. The formation of specialized centromere chromatin containing CENP-A does not require cohesion. Dominant-negative noncleavable RAD21 fails to activate checkpoint but blocks sister chromatid separation and full spindle elongation in anaphase. Mis4 and RAD21 (budding yeast Scc2 and Scc1 homologs, respectively) act in establishing the normal spindle-kinetochore interaction in early mitosis and inhibit sister chromatid separation until the cleavage of RAD21 in anaphase. Checkpoint directly or indirectly monitors the states of cohesion in early mitosis. Full spindle extension occurs with unequal nuclear division in cohesion mutants in the absence of Mad2.
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requirement of chromatid cohesion proteins RAD21 scc1 and mis4 scc2 for normal spindle kinetochore interaction in fission yeast
Current Biology, 2002Co-Authors: Yusuke Toyoda, Koji Nagao, Kanji Furuya, Gohta Goshima, Kohta Takahashi, Mitsuhiro YanagidaAbstract:Abstract Background: Proteins conserved from yeast to human hold two sister chromatids together. The failure to form cohesion in the S phase results in premature separation of chromatids in G2/M. Mitotic kinetochores free from microtubules or the lack of tension are known to activate spindle checkpoint. Results: The loss of chromatid cohesion in fission yeast mutants ( mis4-242 and RAD21-K1 ) leads to the activation of Mad2- and Bub1-dependent checkpoint, possibly due to a diminished microtubule-kinetochore interaction. Bub1, a checkpoint kinase, localizes briefly at early mitotic kinetochores in wild-type, whereas the cohesion mutation greatly increases the duration of kinetochore localization. Bub1 is bound to the central centromere region of mitotic cells. These cohesion mutants are hypersensitive to a tubulin poison and are synthetic lethal with dis1 and bir1/cut17 , which are defective in microtubule-kinetochore interaction. The formation of specialized centromere chromatin containing CENP-A does not require cohesion. Dominant-negative noncleavable RAD21 fails to activate checkpoint but blocks sister chromatid separation and full spindle elongation in anaphase. Conclusions: Mis4 and RAD21 (budding yeast Scc2 and Scc1 homologs, respectively) act in establishing the normal spindle-kinetochore interaction in early mitosis and inhibit sister chromatid separation until the cleavage of RAD21 in anaphase. Checkpoint directly or indirectly monitors the states of cohesion in early mitosis. Full spindle extension occurs with unequal nuclear division in cohesion mutants in the absence of Mad2.
Sabine Vaur - One of the best experts on this subject based on the ideXlab platform.
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The CDK Pef1 and protein phosphatase 4 oppose each other for regulating cohesin binding to fission yeast chromosomes.
eLife, 2020Co-Authors: Adrien Birot, Marta Tormos-pérez, Sabine Vaur, Amélie Feytout, Julien Jaegy, Dácil Alonso Gil, Stéphanie Vazquez, Karl Ekwall, Jean-paul JaverzatAbstract:Cohesin has essential roles in chromosome structure, segregation and repair. Cohesin binding to chromosomes is catalyzed by the cohesin loader, Mis4 in fission yeast. How cells fine tune cohesin deposition is largely unknown. Here, we provide evidence that Mis4 activity is regulated by phosphorylation of its cohesin substrate. A genetic screen for negative regulators of Mis4 yielded a CDK called Pef1, whose closest human homologue is CDK5. Inhibition of Pef1 kinase activity rescued cohesin loader deficiencies. In an otherwise wild-type background, Pef1 ablation stimulated cohesin binding to its regular sites along chromosomes while ablating Protein Phosphatase 4 had the opposite effect. Pef1 and PP4 control the phosphorylation state of the cohesin kleisin RAD21. The CDK phosphorylates RAD21 on Threonine 262. Pef1 ablation, non-phosphorylatable RAD21-T262 or mutations within a RAD21 binding domain of Mis4 alleviated the effect of PP4 deficiency. Such a CDK/PP4-based regulation of cohesin loader activity could provide an efficient mechanism for translating cellular cues into a fast and accurate cohesin response.
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a second wpl1 anti cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by pp4
The EMBO Journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Sabine VaurAbstract:Abstract Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl‐transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA. We report here that Wpl1 anti‐cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co‐immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de‐phosphorylation in a PP4‐dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho‐mimicking alleles dampened Wpl1 anti‐cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post‐replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4‐independent manner. Type 2 cohesin, however, remained DNA‐bound and lost its cohesiveness in a manner depending on Wpl1‐ and PP4‐mediated RAD21 de‐phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
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A second Wpl1 anti‐cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by PP4
The EMBO journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Sabine VaurAbstract:Abstract Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl‐transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA. We report here that Wpl1 anti‐cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co‐immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de‐phosphorylation in a PP4‐dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho‐mimicking alleles dampened Wpl1 anti‐cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post‐replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4‐independent manner. Type 2 cohesin, however, remained DNA‐bound and lost its cohesiveness in a manner depending on Wpl1‐ and PP4‐mediated RAD21 de‐phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
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A second Wpl1 anti‐cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by PP 4
EMBO Journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Sabine Vaur, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Jean‐paul JaverzatAbstract:Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl-transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA We report here that Wpl1 anti-cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co-immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de-phosphorylation in a PP4-dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho-mimicking alleles dampened Wpl1 anti-cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post-replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4-independent manner. Type 2 cohesin, however, remained DNA-bound and lost its cohesiveness in a manner depending on Wpl1- and PP4-mediated RAD21 de-phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
Adrien Birot - One of the best experts on this subject based on the ideXlab platform.
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The CDK Pef1 and protein phosphatase 4 oppose each other for regulating cohesin binding to fission yeast chromosomes.
eLife, 2020Co-Authors: Adrien Birot, Marta Tormos-pérez, Sabine Vaur, Amélie Feytout, Julien Jaegy, Dácil Alonso Gil, Stéphanie Vazquez, Karl Ekwall, Jean-paul JaverzatAbstract:Cohesin has essential roles in chromosome structure, segregation and repair. Cohesin binding to chromosomes is catalyzed by the cohesin loader, Mis4 in fission yeast. How cells fine tune cohesin deposition is largely unknown. Here, we provide evidence that Mis4 activity is regulated by phosphorylation of its cohesin substrate. A genetic screen for negative regulators of Mis4 yielded a CDK called Pef1, whose closest human homologue is CDK5. Inhibition of Pef1 kinase activity rescued cohesin loader deficiencies. In an otherwise wild-type background, Pef1 ablation stimulated cohesin binding to its regular sites along chromosomes while ablating Protein Phosphatase 4 had the opposite effect. Pef1 and PP4 control the phosphorylation state of the cohesin kleisin RAD21. The CDK phosphorylates RAD21 on Threonine 262. Pef1 ablation, non-phosphorylatable RAD21-T262 or mutations within a RAD21 binding domain of Mis4 alleviated the effect of PP4 deficiency. Such a CDK/PP4-based regulation of cohesin loader activity could provide an efficient mechanism for translating cellular cues into a fast and accurate cohesin response.
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a second wpl1 anti cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by pp4
The EMBO Journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Sabine VaurAbstract:Abstract Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl‐transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA. We report here that Wpl1 anti‐cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co‐immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de‐phosphorylation in a PP4‐dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho‐mimicking alleles dampened Wpl1 anti‐cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post‐replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4‐independent manner. Type 2 cohesin, however, remained DNA‐bound and lost its cohesiveness in a manner depending on Wpl1‐ and PP4‐mediated RAD21 de‐phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
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A second Wpl1 anti‐cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by PP4
The EMBO journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Sabine VaurAbstract:Abstract Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl‐transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA. We report here that Wpl1 anti‐cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co‐immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de‐phosphorylation in a PP4‐dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho‐mimicking alleles dampened Wpl1 anti‐cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post‐replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4‐independent manner. Type 2 cohesin, however, remained DNA‐bound and lost its cohesiveness in a manner depending on Wpl1‐ and PP4‐mediated RAD21 de‐phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
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A second Wpl1 anti‐cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by PP 4
EMBO Journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Sabine Vaur, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Jean‐paul JaverzatAbstract:Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl-transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA We report here that Wpl1 anti-cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co-immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de-phosphorylation in a PP4-dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho-mimicking alleles dampened Wpl1 anti-cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post-replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4-independent manner. Type 2 cohesin, however, remained DNA-bound and lost its cohesiveness in a manner depending on Wpl1- and PP4-mediated RAD21 de-phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
Jean-paul Javerzat - One of the best experts on this subject based on the ideXlab platform.
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The CDK Pef1 and protein phosphatase 4 oppose each other for regulating cohesin binding to fission yeast chromosomes.
eLife, 2020Co-Authors: Adrien Birot, Marta Tormos-pérez, Sabine Vaur, Amélie Feytout, Julien Jaegy, Dácil Alonso Gil, Stéphanie Vazquez, Karl Ekwall, Jean-paul JaverzatAbstract:Cohesin has essential roles in chromosome structure, segregation and repair. Cohesin binding to chromosomes is catalyzed by the cohesin loader, Mis4 in fission yeast. How cells fine tune cohesin deposition is largely unknown. Here, we provide evidence that Mis4 activity is regulated by phosphorylation of its cohesin substrate. A genetic screen for negative regulators of Mis4 yielded a CDK called Pef1, whose closest human homologue is CDK5. Inhibition of Pef1 kinase activity rescued cohesin loader deficiencies. In an otherwise wild-type background, Pef1 ablation stimulated cohesin binding to its regular sites along chromosomes while ablating Protein Phosphatase 4 had the opposite effect. Pef1 and PP4 control the phosphorylation state of the cohesin kleisin RAD21. The CDK phosphorylates RAD21 on Threonine 262. Pef1 ablation, non-phosphorylatable RAD21-T262 or mutations within a RAD21 binding domain of Mis4 alleviated the effect of PP4 deficiency. Such a CDK/PP4-based regulation of cohesin loader activity could provide an efficient mechanism for translating cellular cues into a fast and accurate cohesin response.
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a second wpl1 anti cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by pp4
The EMBO Journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Sabine VaurAbstract:Abstract Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl‐transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA. We report here that Wpl1 anti‐cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co‐immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de‐phosphorylation in a PP4‐dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho‐mimicking alleles dampened Wpl1 anti‐cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post‐replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4‐independent manner. Type 2 cohesin, however, remained DNA‐bound and lost its cohesiveness in a manner depending on Wpl1‐ and PP4‐mediated RAD21 de‐phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
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A second Wpl1 anti‐cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by PP4
The EMBO journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Sabine VaurAbstract:Abstract Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl‐transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA. We report here that Wpl1 anti‐cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co‐immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de‐phosphorylation in a PP4‐dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho‐mimicking alleles dampened Wpl1 anti‐cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post‐replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4‐independent manner. Type 2 cohesin, however, remained DNA‐bound and lost its cohesiveness in a manner depending on Wpl1‐ and PP4‐mediated RAD21 de‐phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
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A second Wpl1 anti‐cohesion pathway requires dephosphorylation of fission yeast kleisin RAD21 by PP 4
EMBO Journal, 2017Co-Authors: Adrien Birot, Karen Eguienta, Sabine Vaur, Stéphanie Vazquez, Karl Ekwall, Jean-paul Javerzat, Stéphane Claverol, Marc Bonneu, Jean‐paul JaverzatAbstract:Cohesin mediates sister chromatid cohesion which is essential for chromosome segregation and repair. Sister chromatid cohesion requires an acetyl-transferase (Eso1 in fission yeast) counteracting Wpl1, promoting cohesin release from DNA We report here that Wpl1 anti-cohesion function includes an additional mechanism. A genetic screen uncovered that Protein Phosphatase 4 (PP4) mutants allowed cell survival in the complete absence of Eso1. PP4 co-immunoprecipitated Wpl1 and cohesin and Wpl1 triggered RAD21 de-phosphorylation in a PP4-dependent manner. Relevant residues were identified and mapped within the central domain of RAD21. Phospho-mimicking alleles dampened Wpl1 anti-cohesion activity, while alanine mutants were neutral indicating that RAD21 phosphorylation would shelter cohesin from Wpl1 unless erased by PP4. Experiments in post-replicative cells lacking Eso1 revealed two cohesin populations. Type 1 was released from DNA by Wpl1 in a PP4-independent manner. Type 2 cohesin, however, remained DNA-bound and lost its cohesiveness in a manner depending on Wpl1- and PP4-mediated RAD21 de-phosphorylation. These results reveal that Wpl1 antagonizes sister chromatid cohesion by a novel pathway regulated by the phosphorylation status of the cohesin kleisin subunit.
Christopher Mccabe - One of the best experts on this subject based on the ideXlab platform.
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separase securin and RAD21 in neural cell growth
Journal of Cellular Physiology, 2007Co-Authors: Helen Pemberton, Shiaoyng Chan, Sheueyann Cheng, Jayne Franklyn, Kristien Boelaert, Mark David Kilby, Christopher MccabeAbstract:The key mitotic regulator securin is expressed at low levels in fetal brain compared with adult, and modulates the proliferation of human embryonic neuronal N-Tera2 (NT2) cells. We now examine the function and expression of securin's interacting partner separase, along with RAD21, the functional component of cohesin, which is cleaved by separase following interaction with securin. In contrast to securin, the cleaved forms of separase and RAD21 were highly expressed in human fetal cerebral cortex compared with adult. In a murine model of absent securin expression – the PTTG knock-out mouse – separase and RAD21 were over-expressed in multiple brain regions. In addition, cDNA array analysis of other key mitotic regulators additionally identified cyclin C and sestrin 2 to be induced in the brains of securin-null mice compared with wild type. Further, RAD21 mRNA expression was highly correlated with that of securin, separase, cyclin C and sestrin 2 in fetal brains. In embryonic neuronal NT2 cells, siRNA repression of separase failed to significantly alter cell turnover, whereas repression of securin expression resulted in increased levels of the activated forms of RAD21 and separase, and promoted cell proliferation. Our data suggest that the co-ordinated expression of separase, securin and RAD21 is fundamental for the developing brain. J. Cell. Physiol. 213: 45–53, 2007. © 2007 Wiley-Liss, Inc.
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Separase, securin and RAD21 in neural cell growth.
Journal of cellular physiology, 2007Co-Authors: Helen Pemberton, Shiaoyng Chan, Sheueyann Cheng, Jayne Franklyn, Kristien Boelaert, Mark David Kilby, D.s. Kim, C. Kim, Christopher MccabeAbstract:The key mitotic regulator securin is expressed at low levels in fetal brain compared with adult, and modulates the proliferation of human embryonic neuronal N-Tera2 (NT2) cells. We now examine the function and expression of securin's interacting partner separase, along with RAD21, the functional component of cohesin, which is cleaved by separase following interaction with securin. In contrast to securin, the cleaved forms of separase and RAD21 were highly expressed in human fetal cerebral cortex compared with adult. In a murine model of absent securin expression - the PTTG knock-out mouse - separase and RAD21 were over-expressed in multiple brain regions. In addition, cDNA array analysis of other key mitotic regulators additionally identified cyclin C and sestrin 2 to be induced in the brains of securin-null mice compared with wild type. Further, RAD21 mRNA expression was highly correlated with that of securin, separase, cyclin C and sestrin 2 in fetal brains. In embryonic neuronal NT2 cells, siRNA repression of separase failed to significantly alter cell turnover, whereas repression of securin expression resulted in increased levels of the activated forms of RAD21 and separase, and promoted cell proliferation. Our data suggest that the co-ordinated expression of separase, securin and RAD21 is fundamental for the developing brain.
