title: Is Argonaute 1 the only effective slicer of small RNA-mediated regulation of gene expression in plants?
abstract: To maintain normal growth and development in a plant, gene expression must be under strict surveillance. One of the post-transcriptional regulatory pathways involves small RNA (sRNA)-guided, Argonaute (AGO) protein complex-mediated target cleavages. MicroRNAs (miRNAs) are the well-known sRNA species participating in the cleavage-based regulation of gene expression. In plants, most miRNAs are incorporated into AGO1-associated silencing complexes. Thus, the AGO1 protein is considered to be the most important slicer for sRNA-mediated target cleavages. Previous phylogenetic analysis revealed that AGO1, AGO5, and AGO10 belonged to the same clade in Arabidopsis (Arabidopsis thaliana). In addition, experimental evidence pointed to the possibility that AGO2, AGO7, and AGO10 were implicated in specific miRNA-mediated regulatory pathways. To investigate the potential slicer activities of AGO2, AGO5, AGO7, and AGO10, a comprehensive search was performed for the sRNAs enriched in the four AGO proteins in Arabidopsis. A total of 3 499, 1 618, 4 632, and 63 sRNAs are enriched in AGO2, AGO5, AGO7, and AGO10, respectively. Interestingly, several miRNAs were found to be enriched in AGO2 or AGO5. Transcriptome-wide target identification based on degradome sequencing data uncovered that a number of sRNAs enriched in the four AGOs could perform target cleavages like AGO1-associated miRNAs in plants. Based on the above results, the opinion was put forward that not only AGO1, but also AGO2, AGO5, AGO7, and AGO10 might be essential for the sRNA-mediated regulation of gene expression in plants.
authors.affiliation: College of Life Sciences, Huzhou University, Huzhou 313000, PR China.
authors.forename: Chaogang
authors.initials: C
authors.lastname: Shao
authors.affiliation: Key Laboratory of Hunan Forest Products and Chemical Industry Engineering, Jishou University, Zhangjiajie 427000, PR China mengyijun@zju.edu.cn dongaiwen@yahoo.com.
authors.forename: Ai-Wen
authors.initials: AW
authors.lastname: Dong
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Xuelin Street 16#, Xiasha, Hangzhou 310036, PR China.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Ma
authors.affiliation: College of Life and Environmental Sciences, Hangzhou Normal University, Xuelin Street 16#, Xiasha, Hangzhou 310036, PR China mengyijun@zju.edu.cn dongaiwen@yahoo.com.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Meng
mesh_terms: D060565:Argonaute Proteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000235:genetics*; D018749:RNA, Plant / Q000378:metabolism*
chemical_list: D060565:Argonaute Proteins; D035683:MicroRNAs; D010940:Plant Proteins; D018749:RNA, Plant
keywords: Arabidopsis thaliana; Argonaute; cleavage; degradome; microRNA; small RNA; target.