在纤维环境中被困,定位和定向了线粒状
Apurba Sarkar1, Aniket Jana2, Atharva Agashe2
1School of Mathematical and Computational Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.
bioRxiv : the preprint server for biology
|April 25, 2024
概括
细胞被细胞外基质 (ECM) 封闭,影响了线粒体的方向. 收缩纤维 (RF) 和皮质变形决定了元相板 (MP) 的倾斜,影响纤维环境中的细胞分裂精度.
科学领域:
- 细胞生物学 细胞生物学
- 生物物理学的生物物理.
- 机械生物学 机械生物学
背景情况:
- 精确的线粒轴定位对于细胞健康至关重要.
- 细胞外矩阵 (ECM) 的限制可以改变轴方向和元相板 (MP) 的对齐.
- 了解这些机械影响是细胞分裂的关键.
研究的目的:
- 为了研究纤维ECM的限制如何影响线粒状的定位和MP的方向.
- 为了阐明在MP倾斜中,actin收缩纤维 (RF) 和皮质变形的作用.
- 在不同程度的ECM限制下模拟MP倾斜.
主要方法:
- 利用灵活的,模仿ECM的纳米纤维,对圆形的线粒细胞施加受控的限制.
- 在不同的封闭级别下观察到3D收缩光纤 (RF) 图案.
- 采用了包含中心体,染色体,膜和射频相互作用的随机蒙特卡洛模拟.
- 进行了MP倾斜和皮质变形的机械分析.
主要成果:
- 在ECM封闭中,需要3D射频模式 (低封闭时为三角形,高封闭时为带状).
- 射频3D形状被认为是MP旋转的主要驱动因素.
- 高限制可以导致局部皮质变形,影响MP倾斜.
- MP倾斜与皮质变形,射频模式和MP位置有机械联系.
结论:
- 动因射频和皮质变形协同调节MP倾斜,不对称的MP定位导致显著的倾斜.
- 这项研究提供了关于纤维ECM限制微环境中的线粒分裂的基本见解.
- 这些发现对于理解复杂组织结构中的细胞分裂至关重要.
相关概念视频
02:27The Mitotic Spindle
6.6K
The mitotic spindle—or spindle apparatus—is a eukaryotic, cytoskeletal structure made up of long protein fibers called microtubules. Formed during cell division, the spindle separates sister chromatids and moves them to opposite ends of a parental cell, where the now individual chromosomes are distributed to two daughter cell nuclei.
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures...
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures...
6.6K
02:11Forces Acting on Chromosomes
3.3K
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...
3.3K
02:50Spindle Assembly
3.6K
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...
3.6K
02:57Attachment of Sister Chromatids
3.3K
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...
3.3K
01:39Anaphase A and B
4.1K
Microtubules form through the end-to-end polymerization of tubulin heterodimers. Kinetochore microtubules originate from the spindle poles, and their plus-ends connect with the kinetochores on sister-chromatids. Ndc80 protein complexes, present on the kinetochore, form low-affinity links with the plus end of these kinetochore microtubules.
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
Plus-end depolymerization releases tubulin heterodimers from the terminal region of the microtubule. As tubulin subunits are lost, the Ndc80 complexes detach...
4.1K
02:19The Spindle Assembly Checkpoint
3.1K
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...
3.1K