Up-Regulation of microRNA* Strands by Their Target Transcripts

• Main Authors: Heon-Jin Lee, Su-Hyung Hong, Sung-Min Kang, Ji-Woong Choi
• Format: Article
• Language: English
• Published: MDPI AG 2013-06-01
• Series: International Journal of Molecular Sciences
• Subjects: microRNA (miRNA); pre-miRNA; RISC; Drosha; Dicer; Argonaute (Ago)
• Online Access: http://www.mdpi.com/1422-0067/14/7/13231

During microRNA (miRNA) biogenesis, one strand of a 21–23 nucleotide RNA duplex is preferentially selected for entry into an RNA-induced silencing complex (RISC). The other strand, known as the miRNA* species, is typically thought to be degraded. Previous studies have provided miRNA* selection models, but it remains unclear how the dominance of one arm arises during the biogenesis of miRNA. Using miRNA sponge-like methods, we cloned four tandem target sequences (artificial target) of miR-7b* and then measured miR-7b* expression levels after transfection of the artificial target. miR-7b* levels were found to significantly increase after transfection of the artificial target. We postulate that the abundance of target transcripts drives miRNA arm selection.