Silencing the nuclear actin-related protein AtARP4 in Arabidopsis has multiple effects on plant development, including early flowering and delayed floral senescence
Silencing the nuclear actin-related protein AtARP4 in Arabidopsis has multiple effects on plant development, including early flowering and delayed floral senescence
复制标题
DOI：
10.1111/j.1365-313x.2005.02345.x
复制
发表时间：
2005-03-01
期刊：
影响因子：
7.2
通讯作者：
Meagher, RB
中科院分区：
文献类型：
--
作者：
Kandasamy, MK;Deal, RB;Meagher, RB
肌动蛋白相关蛋白（ARPs）与常规肌动蛋白具有中等程度的序列同源性和基本结构，存在于所有真核生物中。虽然大多数不同的ARPs的功能尚不清楚，但其中一些定位于细胞核，并已被鉴定为各种染色质修饰复合物的组分。利用拟南芥AtARP4抗体，我们发现人类BAF53和酵母Arp4的保守同源物集中在拟南芥、芸苔和烟草细胞的核质中。为了进一步了解ARP4的作用，我们研究了AtARP4表达缺陷的拟南芥植物。arp4-1突变等位基因在启动子区域有T-DNA插入，AtARP4蛋白表达水平适度降低，表型分析显示由于花药发育缺陷导致部分不育。利用RNA干扰靶向AtARP4转录本中独特的3′UTR位点，导致多个独立转基因品系中AtARP4蛋白表达水平大幅降低，并导致植物器官组织改变、开花提前、花衰老延迟和高不育性等强多性表型。Western blot分析和免疫标记表明，AtARP4表达水平的降低与表型的严重程度之间存在明显的相关性。根据我们的研究结果以及酵母和其他生物中AtARP4同源基因的数据，我们认为AtARP4可能通过调节染色质结构和随后的基因调控变化对植物发育产生影响。
Actin-related proteins (ARPs) share moderate sequence homology and basal structure with conventional actins and are found in all eukaryotes. While the functions of most of the divergent ARPs are not clear, several of them are localized to the nucleus and have been identified as components of various chromatin-modifying complexes. Using an antibody to Arabidopsis AtARP4, we found this conserved homolog of human BAF53 and yeast Arp4 is concentrated in the nucleoplasm of Arabidopsis, Brassica, and tobacco cells. To gain further insight into the role of ARP4, we have examined Arabidopsis plants that are defective in AtARP4 expression. Phenotypic analysis of the arp4-1 mutant allele, which has a T-DNA insertion in the promoter region and a moderate reduction in the level of AtARP4 protein expression, revealed partial sterility due to defects in anther development. Targeting the distinct, 3' UTR of AtARP4 transcripts with RNA interference caused a drastic reduction in the level of AtARP4 protein expression in several independent transgenic lines, and resulted in strong pleiotropic phenotypes such as altered organization of plant organs, early flowering, delayed flower senescence and high levels of sterility. Western blot analysis and immunolabeling demonstrated a clear correlation between reductions in the level of AtARP4 expression and severity of the phenotypes. Based on our results and data on the orthologs of AtARP4 in yeast and other organisms, we suggest that AtARP4 is likely to exert its effects on plant development through the modulation of chromatin structure and subsequent changes in gene regulation.