title: CMA33/XCT Regulates Small RNA Production through Modulating the Transcription of Dicer-Like Genes in Arabidopsis.
abstract: Small RNAs (sRNAs) play important regulatory roles in various aspects of plant biology. They are processed from double-stranded RNA precursors by Dicer-like (DCL) proteins. There are three major classes of sRNAs in Arabidopsis: DCL1-dependent microRNA (miRNA), DCL3-dependent heterochromatic siRNA (hc-siRNA), and DCL4-dependent trans-acting siRNA (ta-siRNA). We have previously isolated a mutant with compromised miRNA activity, cma33. Here we show that CMA33 encodes a nuclear localized protein, XAP5 CIRCADIAN TIMEKEEPER (XCT). The cma33/xct mutation led to reduced accumulation of not only miRNAs but also hc-siRNAs and ta-siRNAs. Intriguingly, we found that the expression of DCL1, DCL3, and DCL4, but not other genes in the sRNA biogenesis pathways, was decreased in cma33/xct. Consistent with this, the occupancy of Pol II at DCL1, DCL3, and DCL4 genes was reduced upon the loss of CMA33/XCT. Collectively, our data suggest that CMA33/XCT modulates sRNA production through regulating the transcription of DCLs.
authors.affiliation: Graduate Program, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China; Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; National Institute of Biological Sciences, Zhongguancun Life Science Park, Beijing 102206, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Fang
authors.affiliation: Graduate Program, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China; Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; National Institute of Biological Sciences, Zhongguancun Life Science Park, Beijing 102206, China.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China; Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Lu
authors.affiliation: Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China; National Institute of Biological Sciences, Zhongguancun Life Science Park, Beijing 102206, China.
authors.forename: Zulong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Graduate Program, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China; Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China. Electronic address: qiyijun@tsinghua.edu.cn.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Qi
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D060565:Argonaute Proteins / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D035683:MicroRNAs / Q000096:biosynthesis*; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D017434:Protein Structure, Tertiary; D012319:RNA Polymerase II / Q000378:metabolism; D034741:RNA, Small Interfering / Q000096:biosynthesis; D014158:Transcription, Genetic
chemical_list: C117457:AGO1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D035683:MicroRNAs; D034741:RNA, Small Interfering; D012319:RNA Polymerase II
keywords: Dicer-like; microRNA; processing; small RNA; transcription