Precise mapping of the transcription start sites of human microRNAs using DROSHA knockout cells.
The expression of microRNAs (miRNAs) is primarily regulated during their transcription. However, the transcriptional regulation of miRNA genes has not been studied extensively owing to the lack of sufficient information about the promoters and transcription start sites of most miRNAs.



In this study, we identified the transcription start sites of human primary miRNAs (pri-miRNAs) using DROSHA knockout cells. DROSHA knockout resulted in increased accumulation of pri-miRNAs and facilitated the precise mapping of their 5' end nucleotides using the rapid amplification of cDNA ends (RACE) technique. By analyzing the promoter region encompassing the transcription start sites of miRNAs, we found that the unrelated miRNAs in their sequences have many common elements in their promoters for binding the same transcription factors. Moreover, by analyzing intronic miRNAs, we also obtained comprehensive evidence that miRNA-harboring introns are spliced more slowly than other introns.



The precisely mapped transcription start sites of pri-miRNAs, and the list of transcription factors for pri-miRNAs regulation, will be valuable resources for future studies to understand the regulatory network of miRNAs.
Department of Biochemistry, Chonnam National University Medical School, Gwangju, Korea.|Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju, Korea.
Geon
G
Jeong
Department of Biochemistry, Chonnam National University Medical School, Gwangju, Korea.|Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju, Korea.
Yeong-Hwan
YH
Lim
Department of Biochemistry, Chonnam National University Medical School, Gwangju, Korea. ykk@jnu.ac.kr.|Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju, Korea. ykk@jnu.ac.kr.
Young-Kook
0000-0001-6434-2235
YK
Kim
D002135:Calcium-Binding Proteins; D066255:EGF Family of Proteins; D016228:Endothelial Growth Factors / Q000235:genetics; D045325:HCT116 Cells; D006801:Humans; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D043244:Ribonuclease III / Q000172:deficiency / Q000235:genetics*; D017423:Sequence Analysis, RNA; D014157:Transcription Factors / Q000378:metabolism; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
D002135:Calcium-Binding Proteins; D066255:EGF Family of Proteins; C527877:EGFL7 protein, human; D016228:Endothelial Growth Factors; D035683:MicroRNAs; D014157:Transcription Factors; C517918:DROSHA protein, human; D043244:Ribonuclease III
DROSHA; Knockout; MicroRNA; Promoter; Transcription start site