Authors: Qiongji He Jiejun Peng Fei Yan Lin Lin Yuwen Lu Hongying Zheng Hairu Chen Jianping Chen
Publish Date: 2011/06/23
Volume: 39, Issue: 3, Pages: 3271-3280
Abstract
Arabidopsis thaliana Dicerlike protein 2 AtDCL2 plays an essential role in the RNA interference pathway The function of AtDCL2 and other DCLs has been much studied but little has been done to characterize the DCLs transcripts before they are translated into proteins Here we investigated AtDCL2 transcripts and showed that all 21 introns of AtDCL2 except intron 9 18 20 and 21 could be retained although spliced sequences usually predominated Intron 10 was more frequently retained and transient expression assays in Nicotiana benthamiana leaves showed that when AG/C at the 3′ splicing site of the intron was changed to AG/G the intron was more frequently spliced out Conversely a high retention of intron 18 was obtained if the AG/G at the 3′ splicing site was changed to AG/C These results suggest that the sequence at the 3′ splicing site affects the efficiency of intron splicing The 3′UTRs of AtDCL2 had lengths between 54 and 154 nts and the different 3′UTRs differentially affected the transcriptional levels of fused GFP expressed transiently in N benthamiana Further comparisons and mutation experiments suggested that a putative SBF1 binding site and an AUrich element in the 3′UTR both downregulated expression of the upstream GFP fused to the 3′UTR Conversely a second polyA consensus signal sequence in one 3′UTR upregulated gene expression Our results provide insight into the character of AtDCL2 transcripts and demonstrate the potential complexity of factors that affect the frequency and patterns of alternative splicing
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