2004 | Yoontae Lee, Minju Kim, Jinju Han, Kyu-Hyun Yeom, Sanghyuk Lee, Sung Hee Baek and V Narry Kim
The study by Lee et al. (2004) provides the first direct evidence that microRNA (miRNA) genes are transcribed by RNA polymerase II (pol II). The researchers found that primary miRNA transcripts (pri-miRNAs) contain cap structures and poly(A) tails, which are typical features of class II gene transcripts. Treatment of human cells with α-amanitin, which selectively inhibits pol II activity, reduced the levels of pri-miRNAs. Chromatin immunoprecipitation analyses further showed that pol II is physically associated with the miRNA promoter. The study also detailed the structure of the miRNA gene mir-23a ~27a ~24-2, identifying its promoter and terminator regions. These findings suggest that pol II is the primary or sole RNA polymerase responsible for miRNA gene transcription, providing insights into the regulation and structure of miRNA genes. The results have implications for understanding the complex regulatory networks involving miRNAs and their targets.The study by Lee et al. (2004) provides the first direct evidence that microRNA (miRNA) genes are transcribed by RNA polymerase II (pol II). The researchers found that primary miRNA transcripts (pri-miRNAs) contain cap structures and poly(A) tails, which are typical features of class II gene transcripts. Treatment of human cells with α-amanitin, which selectively inhibits pol II activity, reduced the levels of pri-miRNAs. Chromatin immunoprecipitation analyses further showed that pol II is physically associated with the miRNA promoter. The study also detailed the structure of the miRNA gene mir-23a ~27a ~24-2, identifying its promoter and terminator regions. These findings suggest that pol II is the primary or sole RNA polymerase responsible for miRNA gene transcription, providing insights into the regulation and structure of miRNA genes. The results have implications for understanding the complex regulatory networks involving miRNAs and their targets.