Swi6/HP1的线粒化调节其染色质结合和染色体分离
Yuriko Yoshimura1, Aki Hayashi1, Mayo Tanaka1,2
1Division of Chromatin Regulation, National Institute for Basic Biology, Okazaki, Japan.
概括
由Ark1对裂变酵母Swi6 (一种异色素蛋白1同类物) 的线粒酸化对染色体分离至关重要. 这种酸化对于细胞分裂至关重要,而不是基因沉默.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 异种染色素组装对于真核细胞染色体分离和基因沉默至关重要.
- 异染色素蛋白1 (HP1) 对于异染色素组合至关重要.
- 之前的研究表明,素激酶II (CK2) 酸化HP1蛋白,影响其功能,但线粒酸化的作用尚不清楚.
研究的目的:
- 为了研究裂变酵母Swi6的线粒酸化的功能意义,一个HP1同类.
- 为了确定负责Swi6线粒体酸化的激酶及其点.
- 确定Swi6线粒酸化在染色体分离和基因沉默中的作用.
主要方法:
- 在裂变酵母Swi6.6中确定了线粒酸化位.
- 利用大肠杆菌 (Escherichia coli) 的共同表达系统,研究Ark1的Swi6酸化.
- 进行突变分析 (非酸化和型突变) 和体内研究.
主要成果:
- 在Swi6的N端区域中确定了氨酸残留物,作为Ark1-介导酸化的主要目标.
- 已确认的Swi6血清残留物在体内线粒分裂过程中被酸化.
- 影响酸化部位的突变不会影响异色染色沉默,但会导致染色体分离的缺陷和调节的温度敏感生长.
结论:
- 在裂变酵母中,Ark1-介导的Swi6的线粒化对染色体分离至关重要.
- 在染色体分离中,HP1蛋白的线性酸化起着保留的作用,与基因沉默不同.
相关概念视频
02:19The Spindle Assembly Checkpoint
3.7K
The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
3.7K
02:17Separation of Sister Chromatids
4.3K
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
4.3K
02:11Forces Acting on Chromosomes
3.8K
During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis.
Microtubules and motor proteins exert two types of forces on...
Microtubules and motor proteins exert two types of forces on...
3.8K
02:57Attachment of Sister Chromatids
3.9K
As cells progress into mitosis, the nuclear envelope breaks down, and the condensed chromosomes are exposed to the array of bipolar microtubules of the mitotic spindle. The kinetochore, a large, disc-shaped protein complex, is present at the centromere region of the sister chromatids and acts as a binding site for the microtubules. Usually, the plus-end of a single microtubule is embedded within the kinetochore. However, some kinetochores first establish lateral contact with the side-wall...
3.9K
02:20Cohesins
5.4K
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
5.4K
02:50Spindle Assembly
4.2K
Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a...
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a...
4.2K