Molecular basis of centromeric chromatin required for equal chromosome segregation

染色体平等分离所需的着丝粒染色质的分子基础

• 批准号: 14380334
• 负责人: TAKAHASHI Kohta
• 金额: $ 9.41万
• 依托单位: Kurume University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14380334/
• 关键词: Chromosome; Centromere; CENP-A; Fission yeast; Nucleosome

CENP-A is a centromere-specific histone H3 variant, essential for faithful chromosome segregation. We genetically identified two factors, Mis6 and Ams2, each of which is required for the correct centromere localisation of Cnp1, the fission yeast homologue of CENP-A. In this project, we elucidated following molecular features of Mis6, Ams2 and Cnp1.1.As a multicopy suppressor for mis6-302 mutant, we identified Sim4/Mix1 which forms a stable complex with Mis6. We showed that the Mis6-Sim4 subcomplex is required for mitotic localization of Mad2, but not Bub1, spindle checkpoint protein at centromeres. Furthermore, we demonstrated that Nuf2 is required for maintaining the Mis6-complex on the kinetochore during mitosis. The Mis6-complex physically interacts with Mad2 under the condition that the Mad2-dependent checkpoint is activated. Ectopically expressed Mis6^<1-265> fragment localizes along the mitotic spindle, highlighting the potential binding ability of Mis6 to the spindle microtubule … More s. We propose that the Mis6-complex, in collaboration with the Nuf2-complex, monitors the spindle-kinetochore attachment state and act as a platform for Mad2 to accumulate at unattached kinetochores.2.We demonstrated that there are at least two distinct phases of Cnp1 loading during the cell cycle. A GATA-type transcription factor, Ams2, promotes transcriptional activation of histone genes during S phase and aids in efficient loading of Cnp1 into duplicated centromeres. In Ams2-null cells, Cnp1 fails to localise to centromeres following the passage of S phase ; however, it accumulates again gradually via a backup reloading pathway, which occurs during G2, the gap phase between DNA replication and nuclear division in mitosis. Shortening of G2 length in Ams2-null cells results in marked reduction of Cnp1 accumulation at centromeres, leading to mitotic cell death with chromosome missegregation. The flexibility of Cnp1 loading may account for the plasticity of centromere formation when the authentic centromere is damaged. Less

CENP-A是一种特异性组蛋白H3变体，对于忠实的染色体隔离至关重要。我们通常确定了两个因素MIS6和AMS2，每个因素都需要CNP1的正确丝粒定位，即CENP-A的裂变酵母同源物。在这个项目中，我们阐明了MIS6，AMS2和CNP1.1的分子特征。作为MIS6-302突变体的多拷贝抑制器，我们确定了SIM4/MIX1，该SIM4/MIX1与MIS6形成了稳定的复合物。我们表明，MIS6-SIM4子复合物是MAD2的有丝分裂定位所必需的，而不是Centromeres的主轴检查点蛋白。此外，我们证明了NUF2在有丝分裂过程中维持动力学上的MIS6复合所必需。 MIS6复合物在激活MAD2依赖性检查点的条件下与MAD2物理相互作用。异位表达的MIS6^<1-265>片段沿有丝分裂纺锤体定位，突出了MIS6与纺锤体微管的潜在结合能力…更多。我们建议，MIS6复合物与NUF2-Complex合作监视纺锤体 - 金属色的附件状态，并充当Mad2在未连接的Kinetochore中积累的平台。2。我们证明，在电池周期内至少有两个不同的CNP1载荷阶段。 GATA型转录因子AMS2促进了S相期间组蛋白基因的转录激活，并有助于将CNP1的有效加载到重复的centromeres中。在AMS2-NULL细胞中，CNP1在S相通过后未能定位到丝粒。然而，它通过备份重新加载途径逐渐累积，该途径发生在G2期间，这是有丝分裂中DNA复制与核分裂之间的间隙相。 AMS2无效细胞中G2长度的缩短导致CNP1在cnp1积累显着降低，导致染色体错误分泌的有丝分裂细胞死亡。当真实的丝粒损坏时，CNP1加载的灵活性可能解释了丝粒形成的可塑性。较少的

项目成果

Does a GATA factor make a bed for centromeric nucleosomes?

GATA 因子是否为着丝粒核小体提供床？

• 发表时间: 2003
• 期刊: Cell Cycle 12
• 作者: Chen ES

Ee Sin Chen: "A cell cycle-regulated GATA factor promotes centromeric localization of CENP-A in fission yeast"Molecular Cell. 11(1). 175-187 (2003)

Ee Sin Chen：“细胞周期调节的 GATA 因子促进裂殖酵母中 CENP-A 的着丝粒定位”《分子细胞》。

Chromosome cohesion and segregation. The Molecular Biology in Fission Yeast (Egel R., Ed.)

染色体凝聚和分离。

• 发表时间: 2004
• 作者: Takahashi K;Yanagida M.
• 通讯作者: Yanagida M.

Chromosome cohesion and segregation. in "The molecular biology in fission yeast"

染色体凝聚和分离。

• 发表时间: 2003
• 作者: Sarma K;Nishioka K;Reinberg D;Kohta Takahashi;Aki Minoda;Tatsuro Yuasa;Takeshi Hayashi;Kohta Takahashi
• 通讯作者: Kohta Takahashi

Chromosome cohesion and segregation. In The Molecular Biology in Fission Yeast (Egel R., Ed.)

染色体凝聚和分离。

• 发表时间: 2004
• 作者: Takahashi K