PDF(Pubmed)
Abstract：
UNASSIGNED: The diffusion of cell components such as proteins is crucial to the function of all living cells. The abundance of macromolecules in cells is likely to cause a state of macromolecular crowding, but its effects on the extent of diffusion remain poorly understood.
UNASSIGNED: Here we investigate the diffusion rate in three distinct locations in mesenchymal cell types, namely the open cytoplasm, the stress fibers in the open cytoplasm, and those below the nucleus using three kinds of biologically inert green fluorescent proteins (GFPs), namely a monomer, dimer, and trimer GFP. Fluorescence correlation spectroscopy (FCS) was used to determine the diffusion coefficients.
UNASSIGNED: We show that diffusion tends to be lowered on average in stress fibers and is significantly lower in those located below the nucleus. Our data suggest that the diffusive properties of GFPs, and potentially other molecules as well, are hindered by macromolecular crowding. However, although the size dependence on protein diffusion was also studied for monomer, dimer, and trimer GFPs, there was no significant difference in the diffusion rates among the GFPs of these sizes. These results could be attributed to the lack of significant change in protein size among the selected GFP multimers.
UNASSIGNED: The data presented here would provide a basis for better understanding of the complex protein diffusion in the nonuniform cytoplasm, shedding light on cellular responses to mechanical stress, their local mechanical properties, and reduced turnover in senescent cells.
UNASSIGNED: Here we investigate the diffusion rate in three distinct locations in mesenchymal cell types, namely the open cytoplasm, the stress fibers in the open cytoplasm, and those below the nucleus using three kinds of biologically inert green fluorescent proteins (GFPs), namely a monomer, dimer, and trimer GFP. Fluorescence correlation spectroscopy (FCS) was used to determine the diffusion coefficients.
UNASSIGNED: We show that diffusion tends to be lowered on average in stress fibers and is significantly lower in those located below the nucleus. Our data suggest that the diffusive properties of GFPs, and potentially other molecules as well, are hindered by macromolecular crowding. However, although the size dependence on protein diffusion was also studied for monomer, dimer, and trimer GFPs, there was no significant difference in the diffusion rates among the GFPs of these sizes. These results could be attributed to the lack of significant change in protein size among the selected GFP multimers.
UNASSIGNED: The data presented here would provide a basis for better understanding of the complex protein diffusion in the nonuniform cytoplasm, shedding light on cellular responses to mechanical stress, their local mechanical properties, and reduced turnover in senescent cells.
摘要：
■蛋白质等细胞成分的扩散对所有活细胞的功能至关重要。细胞中大分子的丰度很可能造成大分子拥挤的状态,但它对扩散程度的影响仍然知之甚少。
■在这里，我们研究了间充质细胞类型在三个不同位置的扩散速率，即开放的细胞质，开放细胞质中的应力纤维，和那些在细胞核以下使用三种生物惰性绿色荧光蛋白（GFP），即单体，二聚体，和三聚体GFP。使用荧光相关光谱法(FCS)来确定扩散系数。
■我们表明，在应力纤维中扩散平均趋于降低，而在位于原子核下方的那些纤维中则显着降低。我们的数据表明，GFP的扩散特性，还有潜在的其他分子，受到大分子拥挤的阻碍。然而,尽管还研究了单体对蛋白质扩散的大小依赖性，二聚体，和三聚体GFP，这些大小的GFP之间的扩散速率没有显着差异。这些结果可归因于在所选择的GFP多聚体中缺乏蛋白质大小的显著变化。
■此处提供的数据将为更好地理解复杂蛋白质在不均匀细胞质中的扩散提供基础，照亮细胞对机械应力的反应，它们的局部机械性能，减少衰老细胞的周转。
■在这里，我们研究了间充质细胞类型在三个不同位置的扩散速率，即开放的细胞质，开放细胞质中的应力纤维，和那些在细胞核以下使用三种生物惰性绿色荧光蛋白（GFP），即单体，二聚体，和三聚体GFP。使用荧光相关光谱法(FCS)来确定扩散系数。
■我们表明，在应力纤维中扩散平均趋于降低，而在位于原子核下方的那些纤维中则显着降低。我们的数据表明，GFP的扩散特性，还有潜在的其他分子，受到大分子拥挤的阻碍。然而,尽管还研究了单体对蛋白质扩散的大小依赖性，二聚体，和三聚体GFP，这些大小的GFP之间的扩散速率没有显着差异。这些结果可归因于在所选择的GFP多聚体中缺乏蛋白质大小的显著变化。
■此处提供的数据将为更好地理解复杂蛋白质在不均匀细胞质中的扩散提供基础，照亮细胞对机械应力的反应，它们的局部机械性能，减少衰老细胞的周转。
