周核染色体结合在维持基因组稳定性的作用
Karim Mekhail1, Jan Seebacher, Steven P Gygi
1Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|November 11, 2008
概括
内核膜 (INM) 蛋白质通过将它们与核外围连接起来来稳定重复性DNA (rDNA). 这种相互作用对基因组稳定至关重要,独立于传统的rDNA沉默机制.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 重复的DNA序列容易发生同源重组,导致基因组不稳定.
- 沉默色素被认为可以通过限制重组来稳定重复的DNA.
- 在芽酵母中,核糖体DNA (rDNA) 的稳定性依赖于Sir2-介导的沉默.
研究的目的:
- 研究一种涉及稳定发芽酵母中重复DNA (rDNA) 的新型蛋白质网络.
- 阐明内核膜 (INM) 蛋白在rDNA稳定性和局部化中的作用.
主要方法:
- 研究了与rDNA相关的沉默因子和内核膜 (INM) 蛋白质之间的蛋白质相互作用.
- 利用INM和沉默蛋白的删除突变来评估rDNA稳定性和局部化.
- 雇佣了rDNA重复的人工向INM,以研究对不稳定的影响.
主要成果:
- 删除INM或沉默蛋白质会破坏周核rDNA的定位并破坏重复的稳定性.
- 将rDNA重复连接到INM可以抑制缺乏特定沉默蛋白质的细胞的不稳定性.
- INM蛋白稳定rDNA独立于Sir2依赖的rDNA沉默.
结论:
- 内核膜 (INM) 蛋白质在周核染色体定位和rDNA稳定性中起着至关重要的作用.
- 连接到核外围对于保持重复性DNA序列的稳定性至关重要.
- 这种INM介导的基因组稳定机制在真核生物中得到保护.
相关概念视频
Attachment of Sister Chromatids
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 of a...
Forces Acting on Chromosomes
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...
Forces Acting on Chromosomes
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...
Replication in Eukaryotes
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Replication in Eukaryotes
Overview
Chromosome Structure
A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication.
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...


