title: NOT2 proteins promote polymerase II-dependent transcription and interact with multiple MicroRNA biogenesis factors in Arabidopsis.
abstract: MicroRNAs (miRNAs) play key regulatory roles in numerous developmental and physiological processes in animals and plants. The elaborate mechanism of miRNA biogenesis involves transcription and multiple processing steps. Here, we report the identification of a pair of evolutionarily conserved NOT2_3_5 domain-containing-proteins, NOT2a and NOT2b (previously known as At-Negative on TATA less2 [NOT2] and VIRE2-INTERACTING PROTEIN2, respectively), as components involved in Arabidopsis thaliana miRNA biogenesis. NOT2 was identified by its interaction with the Piwi/Ago/Zwille domain of DICER-LIKE1 (DCL1), an interaction that is conserved between rice (Oryza sativa) and Arabidopsis thaliana. Inactivation of both NOT2 genes in Arabidopsis caused severe defects in male gametophytes, and weak lines show pleiotropic defects reminiscent of miRNA pathway mutants. Impairment of NOT2s decreases the accumulation of primary miRNAs and mature miRNAs and affects DCL1 but not HYPONASTIC LEAVES1 (HYL1) localization in vivo. In addition, NOT2b protein interacts with polymerase II and other miRNA processing factors, including two cap binding proteins, CBP80/ABH1, CBP20, and SERRATE (SE). Finally, we found that the mRNA levels of some protein coding genes were also affected. Therefore, these results suggest that NOT2 proteins act as general factors to promote the transcription of protein coding as well as miRNA genes and facilitate efficient DCL1 recruitment in miRNA biogenesis.
authors: State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors: Lulu
authors: L
authors: Wang
authors: Xianwei
authors: X
authors: Song
authors: Lianfeng
authors: L
authors: Gu
authors: Xin
authors: X
authors: Li
authors: Shouyun
authors: S
authors: Cao
authors: Chengcai
authors: C
authors: Chu
authors: Xia
authors: X
authors: Cui
authors: Xuemei
authors: X
authors: Chen
authors: Xiaofeng
authors: X
authors: Cao
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000378:metabolism*; D009154:Mutation; D051479:Plant Infertility / Q000235:genetics; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D035165:Transcription Factors, General / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D039381:RNA Cap-Binding Proteins
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D035683:MicroRNAs; D012319:RNA Polymerase II; D016601:RNA-Binding Proteins; D043244:Ribonuclease III; D035165:Transcription Factors, General; C454128:CBP20 protein, Arabidopsis; C420966:HYL1 protein, Arabidopsis; C585565:Not2a protein, Arabidopsis; C523538:VIP2 protein, Arabidopsis; C402383:DCL1 protein, Arabidopsis; C435105:At2g13540 protein, Arabidopsis; D039381:RNA Cap-Binding Proteins