Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a ...Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a novel integrator of spindle checkpoint signaling. However, it is unclear how NEK2A regulates kinetochore-microtubule attachment in mitosis. Here we show that NEK2A phosphorylates human Sgo 1 and such phosphorylation is essential for faithful chromosome congression in mitosis. NEK2A binds directly to HsSgol in vitro and co-distributes with HsSgol to the kinetochore of mitotic cells. Our in vitro phosphorylation experiment demonstrated that HsSgo 1 is a substrate of NEK2A and the phosphorylation sites were mapped to Ser^14 and Ser^507 as judged by the incorporation of 32^P. Although such phosphorylation is not required for assembly of HsSgo 1 to the kinetochore, expression of non-phosphorylatable mutant HsSgo 1 perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. These findings reveal a key role for the NEK2A-mediated phosphorylation ofHsSgo 1 in orchestrating dynamic kinetochore-microtubule interaction. We propose that NEK2A-mediated phosphorylation of human Sgo 1 provides a link between centromeric cohesion and spindle microtubule attachment at the kinetochores.展开更多
In mitosis,accurate chromosome segregation depends on the kinetochore,a supermolecular machinery that couples dynamic spin-dle microtubules to centromeric chromatin.However,the structure–activity relationship of the ...In mitosis,accurate chromosome segregation depends on the kinetochore,a supermolecular machinery that couples dynamic spin-dle microtubules to centromeric chromatin.However,the structure–activity relationship of the constitutive centromere-associated network(CCAN)during mitosis remains uncharacterized.Building on our recent cryo-electron microscopic analyses of human CCAN structure,we investigated how dynamic phosphorylation of human CENP-N regulates accurate chromosome segregation.Our mass spectrometric analyses revealed mitotic phosphorylation of CENP-N by CDK1,which modulates the CENP-L–CENP-N interaction for accurate chromosome segregation and CCAN organization.Perturbation of CENP-N phosphorylation is shown to prevent proper chromosome alignment and activate the spindle assembly checkpoint.These analyses provide mechanistic insight into a previously undefined link between the centromere–kinetochore network and accurate chromosome segregation.展开更多
Dear Editor,The promptness and continuous expansion of the coronavirus disease 2019(COVID-19)pandemic,elicited by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and its variants,has presented an unpreceden...Dear Editor,The promptness and continuous expansion of the coronavirus disease 2019(COVID-19)pandemic,elicited by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and its variants,has presented an unprecedented impact on human health(WHO Coronavirus(COVID-19)Dashboard,2021).Although vaccination has attenuated the severe symptoms,there is no specific antiviral medication available for preventing the viral spread(Drayman et al.,2021).展开更多
Stable transmission of genetic information during cell division requires faithful mitotic spindle assembly and chromosome segregation.In eukaryotic cells,nuclear envelope breakdown(NEBD)is required for proper chromoso...Stable transmission of genetic information during cell division requires faithful mitotic spindle assembly and chromosome segregation.In eukaryotic cells,nuclear envelope breakdown(NEBD)is required for proper chromosome segregation.Although a list of mitotic kinases has been implicated in NEBD,how they coordinate their activity to dissolve the nuclear envelope and protein machinery such as nuclear pore complexes was unclear.Here,we identified a regulatory mechanism in which Nup62 is acetylated by TIP60 in human cell division.Nup62 is a novel substrate of TIP60,and the acetylation of Lys432 by TIP60 dissolves nucleoporin Nup62-Nup58-Nup54 complex during entry into mitosis.Importantly,this acetylation-elicited remodeling of nucleoporin complex promotes the distribution of Nup62 to the mitotic spindle,which is indispensable for orchestrating correct spindle orientation.Moreover,suppression of Nup62 perturbs accurate chromosome segregation during mitosis.These results establish a previously uncharacterized regulatory mechanism in which TIP60-elicited nucleoporin dynamics promotes chromosome segregation in mitosis.展开更多
Dear Editor,The hallmarks of cancer comprise several distinct biological characteristics acquired during the multistep development of human tumors with the unique feature of genomic instability(Shen,2011).These cancer...Dear Editor,The hallmarks of cancer comprise several distinct biological characteristics acquired during the multistep development of human tumors with the unique feature of genomic instability(Shen,2011).These cancer characteristics include sustaining proliferative signaling,evading growth suppressors,resisting cell death,enabling replicative immortality,inducing angiogenesis,and activating invasion and metastasis(Chen et al.,2011;Song et al.,2018).Triple-negative breast cancer(TNBC),an aggressive disease with increased risks for visceral metastases,has a poor prognosis due to unavailable and viable therapeutic targets(Bianchini et al.,2016).A TNBC diagnosis indicates that cancer cells test negative for three key receptors:estrogen receptor,progesterone receptor,and human epidermal growth factor receptor 2(Bianchini et al.,2016).The absence of these three receptors renders existing hormone and targeted therapies ineffective.展开更多
Dear Editor,Promyelocytic leukemia(PML)is the scaffold protein that organizes PML bod-ies,which are nuclear membraneless organelles involved in various biologi-cal processes,including tumor suppres-sion and antiviral ...Dear Editor,Promyelocytic leukemia(PML)is the scaffold protein that organizes PML bod-ies,which are nuclear membraneless organelles involved in various biologi-cal processes,including tumor suppres-sion and antiviral responses(Ugge et al.,2022).Early electron microscopic analy-ses revealed contacts between the sur-face of PML bodies and chromatin struc-ture(Corpet et al.,2020).In fact,sev-eral chromatin and cell cycle regulators,such as TIP60,P300,and heterochro-matin protein 1(HP1),are localized in PML bodies in interphase cells(Corpet et al.,2020).展开更多
Accurate chromosome segregation in mitosis depends on kinetochores that connect centromeric chromatin to spindle microtubules.Centromeres are captured by individual microtubules via a kinetochore constitutive centrome...Accurate chromosome segregation in mitosis depends on kinetochores that connect centromeric chromatin to spindle microtubules.Centromeres are captured by individual microtubules via a kinetochore constitutive centromere-associated network(CCAN)during chromosome segregation.CCAN contains 16 subunits,including CENP-W and CENP-T.However,the molecular recognition and mitotic regulation of the CCAN assembly remain elusive.Here,we revealed that CENP-W binds to the histone fold domain and an uncharacterized N-terminal region of CENP-T.Aurora B phosphorylates CENP-W at threonine 60,which enhances the interaction between CENP-W and CENP-T to ensure robust metaphase chromosome alignment and accurate chromosome segregation in mitosis.These findings delineate a conserved signaling cascade that integrates protein phosphorylation with CCAN integrity for the maintenance of genomic stability.展开更多
Dear Editor,Chromosome segregation in eukary-otes relies on intricate interactions between spindle microtubules and centromeres(Liu et al,2020).Recently,using cryo-electron microscopy(cryo-EM)alongside functional anal...Dear Editor,Chromosome segregation in eukary-otes relies on intricate interactions between spindle microtubules and centromeres(Liu et al,2020).Recently,using cryo-electron microscopy(cryo-EM)alongside functional analyses,we and other groups unveiled the molecular basis of how human kinetochore constitutive centromere-associated network(CCAN)interacts with duplex DNA and facilitates accurate chromosome segregation(Pesenti et al,2022;Tian et al.,2022;Yatskevich et al,.2022).While these investigations offer a foundational understanding of the physical and chemical interdependency of CCAN constituents,the functional significance of individual contacts within this complex remains to be fully elucidated.展开更多
基金We thank members of our group for insightful discussion during the course of this study.This work was supported by grants from Chinese Academy of Science(KSCX1-YW-R65,KSCX2-YW-H10)National Basic Research Program of China(2002CB713700)+4 种基金Hi-Tech Research and Development Program of China(2001AA215331)Chinese Minister of Education(20020358051 to XY,PCSIRT0413 to XD)National Natural Science Foundation of China(39925018,30270293 to XY,30500183 to XD,30600222 to JY)National Institutes of Health(USA)(DK56292,CA92080)to XY(a Georgia Cancer Coalition Eminent Scholar)JY was supported by China Postdoctor(2005037560).
文摘Chromosome segregation in mitosis is orchestrated by the interaction of the kinetochore with spindle microtubules. Our recent study shows that NEK2A interacts with MAD 1 at the kinetochore and possibly functions as a novel integrator of spindle checkpoint signaling. However, it is unclear how NEK2A regulates kinetochore-microtubule attachment in mitosis. Here we show that NEK2A phosphorylates human Sgo 1 and such phosphorylation is essential for faithful chromosome congression in mitosis. NEK2A binds directly to HsSgol in vitro and co-distributes with HsSgol to the kinetochore of mitotic cells. Our in vitro phosphorylation experiment demonstrated that HsSgo 1 is a substrate of NEK2A and the phosphorylation sites were mapped to Ser^14 and Ser^507 as judged by the incorporation of 32^P. Although such phosphorylation is not required for assembly of HsSgo 1 to the kinetochore, expression of non-phosphorylatable mutant HsSgo 1 perturbed chromosome congression and resulted in a dramatic increase in microtubule attachment errors, including syntelic and monotelic attachments. These findings reveal a key role for the NEK2A-mediated phosphorylation ofHsSgo 1 in orchestrating dynamic kinetochore-microtubule interaction. We propose that NEK2A-mediated phosphorylation of human Sgo 1 provides a link between centromeric cohesion and spindle microtubule attachment at the kinetochores.
基金supported by grants from the Ministry of Science and Technology of the People’s Republic of China and the National Natural Science Foundation of China(2022YFA1303100,2022YFA0806800,92153302,32090040,92254302,21922706,91853115 to X.L.,2017YFA0503600,31621002,U1532109,91853133 to J.Z.,32170733,2017YFA0102900,31871359 to Z.D.,32000858 to T.T.)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB37010105 to J.Z.and XDB19040000 to X.L.)+3 种基金the Ministry of Education(IRT_17R102,20113402130010,YD2070006001 to X.L.)Anhui Provincial Natural Science Foundation(2108085J15 to Z.D.,2008085QC145 to T.T.)the Fundamental Research Funds for the Central Universities(WK2070000171 to T.T.)the University of Science and Technology of China Research Funds of the Double First-Class Initiative(YD2070002015 to X.Z.)。
文摘In mitosis,accurate chromosome segregation depends on the kinetochore,a supermolecular machinery that couples dynamic spin-dle microtubules to centromeric chromatin.However,the structure–activity relationship of the constitutive centromere-associated network(CCAN)during mitosis remains uncharacterized.Building on our recent cryo-electron microscopic analyses of human CCAN structure,we investigated how dynamic phosphorylation of human CENP-N regulates accurate chromosome segregation.Our mass spectrometric analyses revealed mitotic phosphorylation of CENP-N by CDK1,which modulates the CENP-L–CENP-N interaction for accurate chromosome segregation and CCAN organization.Perturbation of CENP-N phosphorylation is shown to prevent proper chromosome alignment and activate the spindle assembly checkpoint.These analyses provide mechanistic insight into a previously undefined link between the centromere–kinetochore network and accurate chromosome segregation.
基金supported by NIH grants(DK56292,DK115812,U54MD007602-33S3,S21MD000101,and CA164133).
文摘Dear Editor,The promptness and continuous expansion of the coronavirus disease 2019(COVID-19)pandemic,elicited by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and its variants,has presented an unprecedented impact on human health(WHO Coronavirus(COVID-19)Dashboard,2021).Although vaccination has attenuated the severe symptoms,there is no specific antiviral medication available for preventing the viral spread(Drayman et al.,2021).
基金supported by grants from the National Key Re-search and Development Program of China(2017YFA0503600 and 2016YFA0100500)the National Natural Science Founda-tion of China(31621002,32090040,91854203,21922706,91853115,92153302,22177106,92053104,31970655,and 32100612)+2 种基金the Ministry of Education(IRT_17R102),Anhui Provincial Natural Science Foundation(2108085J15)the Strate-gic Priority Research Program of the Chinese Academy of Sci-ences(XDB19040000)the Fundamental Research Funds for the Central Universities(WK2070000066 and WK2070000194).
文摘Stable transmission of genetic information during cell division requires faithful mitotic spindle assembly and chromosome segregation.In eukaryotic cells,nuclear envelope breakdown(NEBD)is required for proper chromosome segregation.Although a list of mitotic kinases has been implicated in NEBD,how they coordinate their activity to dissolve the nuclear envelope and protein machinery such as nuclear pore complexes was unclear.Here,we identified a regulatory mechanism in which Nup62 is acetylated by TIP60 in human cell division.Nup62 is a novel substrate of TIP60,and the acetylation of Lys432 by TIP60 dissolves nucleoporin Nup62-Nup58-Nup54 complex during entry into mitosis.Importantly,this acetylation-elicited remodeling of nucleoporin complex promotes the distribution of Nup62 to the mitotic spindle,which is indispensable for orchestrating correct spindle orientation.Moreover,suppression of Nup62 perturbs accurate chromosome segregation during mitosis.These results establish a previously uncharacterized regulatory mechanism in which TIP60-elicited nucleoporin dynamics promotes chromosome segregation in mitosis.
基金supported by grants from the Ministry of Science and Technology of China(MOST,2017YFA0503600)the National Natural Science Foundation of China(NSFC,81630080,31621002,32090040,21922706,91854203,and 91853115)+1 种基金China Postdoctoral Science Foundation grant(2019M662181)the US National Institutes of Health(NIH,DK56292,DK115812,S21MD000101,and CA164133).
文摘Dear Editor,The hallmarks of cancer comprise several distinct biological characteristics acquired during the multistep development of human tumors with the unique feature of genomic instability(Shen,2011).These cancer characteristics include sustaining proliferative signaling,evading growth suppressors,resisting cell death,enabling replicative immortality,inducing angiogenesis,and activating invasion and metastasis(Chen et al.,2011;Song et al.,2018).Triple-negative breast cancer(TNBC),an aggressive disease with increased risks for visceral metastases,has a poor prognosis due to unavailable and viable therapeutic targets(Bianchini et al.,2016).A TNBC diagnosis indicates that cancer cells test negative for three key receptors:estrogen receptor,progesterone receptor,and human epidermal growth factor receptor 2(Bianchini et al.,2016).The absence of these three receptors renders existing hormone and targeted therapies ineffective.
基金supported by grants from the Ministry of Science and Technology of the People’s Republic of China and the National Natural Science Foundation of China(2022YFA1303100,32090040,92254302,92153302,2022YFA0806800,2022YFA1302700,2017YFA0503600,31621002,91853115,21922706,22177106)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB19040000)+1 种基金the Ministry of Education(IRT_17R102 and 2011340213001)the Fundamental Research Funds for the Central Universities(WK2070000194).
文摘Dear Editor,Promyelocytic leukemia(PML)is the scaffold protein that organizes PML bod-ies,which are nuclear membraneless organelles involved in various biologi-cal processes,including tumor suppres-sion and antiviral responses(Ugge et al.,2022).Early electron microscopic analy-ses revealed contacts between the sur-face of PML bodies and chromatin struc-ture(Corpet et al.,2020).In fact,sev-eral chromatin and cell cycle regulators,such as TIP60,P300,and heterochro-matin protein 1(HP1),are localized in PML bodies in interphase cells(Corpet et al.,2020).
基金supported by the National Key Research and Development Program of China(2022YFA1303100,2022YFA0806800,2022YFA1302700,and 2017YFA0503600)the National Natural Science Foundation of China(32090040,92254302,92153302,92253301,22137007,32170733,and 31871359)+3 种基金the Ministry of Education(IRT_17R102)the Plans for Major Provincial Science&Technology Projects of Anhui Province(202303a0702003)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB19040000)the Fundamental Research Funds for the Central Universities(WK2070000066 and WK2070000194).
文摘Accurate chromosome segregation in mitosis depends on kinetochores that connect centromeric chromatin to spindle microtubules.Centromeres are captured by individual microtubules via a kinetochore constitutive centromere-associated network(CCAN)during chromosome segregation.CCAN contains 16 subunits,including CENP-W and CENP-T.However,the molecular recognition and mitotic regulation of the CCAN assembly remain elusive.Here,we revealed that CENP-W binds to the histone fold domain and an uncharacterized N-terminal region of CENP-T.Aurora B phosphorylates CENP-W at threonine 60,which enhances the interaction between CENP-W and CENP-T to ensure robust metaphase chromosome alignment and accurate chromosome segregation in mitosis.These findings delineate a conserved signaling cascade that integrates protein phosphorylation with CCAN integrity for the maintenance of genomic stability.
基金supported by grants from the Ministry of Science and Technology of China and the National Natural Science Foundation of China(2022YFA1303100,32090040,92254302,2022YFA0806800,92153302,W2411017,32400593,92253301,22137007,and 92053104)the Plansfor Major Provincial Science&Technology Projects of Anhui Province(202303a0702003).F.A.,L.Z.,X.L.,and X.Y.conceived the project and designed the experiments.O.A.D.and X.G.performed the chemical screening.O.A.D.and F.Y.performed the experiments and analyzed the data.O.A.D.,L.Z.,and X.Y.wrote the manuscript.X.L.and X.Y.supervised the project.
文摘Dear Editor,Chromosome segregation in eukary-otes relies on intricate interactions between spindle microtubules and centromeres(Liu et al,2020).Recently,using cryo-electron microscopy(cryo-EM)alongside functional analyses,we and other groups unveiled the molecular basis of how human kinetochore constitutive centromere-associated network(CCAN)interacts with duplex DNA and facilitates accurate chromosome segregation(Pesenti et al,2022;Tian et al.,2022;Yatskevich et al,.2022).While these investigations offer a foundational understanding of the physical and chemical interdependency of CCAN constituents,the functional significance of individual contacts within this complex remains to be fully elucidated.
