ABSTRACT

Interactions of chromatin with the nuclear lamina imposes a radial genome distribution important for nuclear functions. How physical properties of chromatin affect these interactions is unclear. We used polymer simulations to model how physical parameters of chromatin affect its interaction with the lamina. Impact of polymer stiffness is greater than stretching on its configurations at the lamina; these are manifested as trains describing extended interactions, and loops describing desorbed regions . Conferring an attraction potential leads to persistent interaction and adsorption-desorption regimes manifested by fluctuations between trains and loops. These are modulated by polymer stiffness and stretching, with a dominant impact of stiffness on resulting structural configurations. We infer that flexible euchromatin is more prone to stochastic interactions with lamins than rigid heterochromatin characterizing constitutive LADs. Our models provide insights on the physical properties of chromatin as a polymer which affect the dynamics and patterns of interactions with the nuclear lamina.

摘要

染色质与核层的相互作用使径向基因组分布对于核功能很重要。染色质的物理特性如何影响这些相互作用尚不清楚。我们使用聚合物模拟来建模染色质的物理参数如何影响其与叶片的相互作用。聚合物刚度的影响大于在层板上拉伸时的拉伸。这些表现为描述扩展相互作用的序列和描述解吸区域的循环。赋予潜在的吸引力会导致持续的相互作用和吸附-解吸机制，表现为火车和环路之间的波动。这些通过聚合物的刚度和拉伸来调节，刚度对最终的结构构型具有主要影响。我们推断，与表征组成型LAD的刚性异染色质相比，柔性常染色质更倾向于与lamins进行随机相互作用。我们的模型提供了染色质作为聚合物的物理特性的见解，染色质会影响与核层板相互作用的动力学和模式。