拟南芥肌动蛋白相关蛋白基因AtARP5和AtARP6共同参与DNA复制  

Both Arabidopsis Actin-Related Protein Gene AtARP5 and AtARP6 Participate in DNA Replication

作　　者：吴迪 安增选[1,2] 樊天谊 朱炎 WU Di;AN Zengxuan;FAN Tianyi;ZHU Yan(Institute of Plant Biology,School of Life Sciences,Fudan University,Shanghai 200438,China;State Key Laboratory of Genetic Engineering,Fudan University,Shanghai 200438,China)

机构地区：[1]复旦大学生命科学学院植物科学研究所,上海200438 [2]复旦大学遗传工程国家重点实验室,上海200438

出　　处：《复旦学报（自然科学版）》2021年第6期752-758,共7页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金(32070201,31671341)。

摘　　要：染色质重塑因子是一类利用ATP水解的能量主动重塑染色质结构的蛋白质,其中的INO80亚家族包括两个在进化中高度保守的重要成员,INO80和SWR1.两者通过结合包括肌动蛋白相关蛋白(Actin-Related Protein,ARP)在内的多个亚基,以复合物的形式对染色质结构动态调控,在真核生物的多个表观遗传调控途径中发挥重要的功能.尽管都属于ARP成员,ARP5是INO80重塑复合物的特异性成员,而ARP6是SWR1重塑复合物的特异性成员.在模式植物拟南芥(Arabidopsis thaliana)中,AtINO80和AtPIE1(拟南芥SWR1)基因缺失的双突变体致死.我们构建了AtARP5和AtARP6缺失突变体的双突变体atarp5-2 atarp6-1,用以研究两者在植物生长发育中的功能互作.我们发现,相对于野生型植物和各自的单突变体,双突变体atarp5-2 atarp6-1植物生长明显受抑制.细致的细胞观察显示,双突变体植物叶肉栅栏细胞大小和数量都减小,植物细胞核倍性下降,细胞周期和DNA复制相关基因的转录水平异常上调.Pull-down实验和BiFC实验证实,AtARP5和AtARP6都能够与DNA解旋酶RVB1结合.由于RVB1对于细胞增殖和植物生长至关重要,因此两个不同的肌动蛋白相关蛋白可能依赖于RVB1协同调控DNA复制以及相关细胞周期进程.Chromatin remodeling factors are a family of proteins that actively remodel local or global chromatin structure by utilizing energy from ATP hydrolysis.The INO80 chromatin remodeling subfamily consists of two important members highly conserved in evolution,INO80 and SWR1.Both can interact with multiple subunits including actin related protein(ARP)in the form of large protein complex to modulate chromatin architecture,and play important regulatory roles in several biological pathways conserved in eukaryotes.Despite of belonging to the same ARP family,ARP5 is proved as a specific subunit of INO80 remodeling complex,while ARP6 functions as an indispensable member of SWR1 remodeling complex.In model plant Arabidopsis thaliana,the simultaneous knockout of AtINO80 and AtPIE1(Arabidopsis SWR1 gene)leads to plant lethality.Therefore,we constructed the double mutants of atarp5 and atarp6 deletion mutants to study their functional interactions in the context of plant growth and development.Compared to the wild-type and respective single mutants,the growth of atarp5-2 atarp6-1 double mutant was significantly inhibited.Detailed cellular observation showed that the size and number of palisade cells in rosette leaves were decreased,accompanied with the decrease of plant cell ploidy.The relative transcription level of certain cell cycle-and DNA replication-related genes were mis-regulated.Our Pull-down experiment and BiFC experiment revealed that both AtARP5 and AtARP6 can interact with DNA helicase RVB1.Since RVB1 is essential for cell proliferation and plant growth,two different ARPs may synergistically regulate DNA replication and related cell cycle progression in a RVB1-dependent way.

关 键 词：拟南芥肌动蛋白相关蛋白5 拟南芥肌动蛋白相关蛋白6 细胞增殖 细胞内复制 

分 类 号：Q5[生物学—生物化学]