KIF4A尾部结构域与不同结构DNA的相互作用

Interaction of KIF4A tail domain with DNA of different structures

在有丝分裂期的细胞中,染色体驱动蛋白KIF4A的染色体定位对细胞分裂进程影响显著,KIF4A的羧基端尾部是参与调控其染色体定位的主要结构.为了探究KIF4A结合DNA的特性,利用细菌表达KIF4A尾部功能域蛋白KIF4A-C278,并应用纯化后的蛋白分别与线性双螺旋DNA和超螺旋DNA结合.实验结果显示,KIF4A-C278蛋白不与线性双螺旋质粒DNA结合,但可与高级结构的超螺旋质粒DNA结合.说明KIF4A羧基端尾部功能域会识别高级结构的DNA并与其相互作用.这预示着在有丝分裂初期染色质趋向于凝集成染色体时,DNA开始形成高级结构,KIF4A可能会借助于这一功能启动染色体定位.

In mitotic cells,the chromosomal location of the chromosomal kinesin KIF4A has a significant effect on the process of cell division.The carboxy-terminal tail of KIF4A is the main structure involved in regulating its chromosomal positioning.In order to explore its dependence on self-binding DNA characteristics,bacteria were used to express the KIF4A tail domain protein KIF4A-C278,and the purified protein was combined respectively with linear double-helical DNA and super-coiled DNA.The results showed that KIF4A-C278 protein did not bind to linear double-helical plasmid DNA,but can bind to super-coiled plasmid DNA with high-level structure.It demonstrated that the functional domain of KIF4A carboxy-terminal tail may recognize and interact with DNA with high-level structure.This indicates that when mitosis begins and chromatin tends to converge into chromosomes,DNA begins to form high-level structures.KIF4A may use this function to initiate chromosome positioning.