MicroRNAs, which regulate gene expression, are transcribed as longer sequences that are processed to produce the mature form. Two nuclease enzymes, Drosha and Dicer, are known to act sequentially to trim the microRNA to size. Here, however, a subset of microRNAs that includes miR-451, important for erythropoiesis, is found to be processed independently of Dicer. Rather, the Argonaute protein — part of the complex that aligns microRNA and messenger RNA — carries out the secondary cleavage.
- Sihem Cheloufi
- Camila O. Dos Santos
- Gregory J. Hannon