Heme enables proper positioning of Drosha and DGCR8 on primary microRNAs.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29170488.
- Also identified by DOI 10.1038/s41467-017-01713-y and PMC identifier 5700927.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
MicroRNAs regulate the expression of many proteins and require specific maturation steps. Primary microRNA transcripts (pri-miRs) are cleaved by Microprocessor, a complex containing the RNase Drosha and its partner protein, DGCR8. Although DGCR8 is known to bind heme, the molecular role of heme in pri-miR processing is unknown. Here we show that heme is critical for Microprocessor to process pri-miRs with high fidelity. Furthermore, the degree of inherent heme dependence varies for different pri-miRs. Heme-dependent pri-miRs fail to properly recruit Drosha, but heme-bound DGCR8 can correct erroneous binding events. Rather than changing the oligomerization state, heme induces a conformational change in DGCR8. Finally, we demonstrate that heme activates DGCR8 to recognize pri-miRs by specifically binding the terminal loop near the 3' single-stranded segment.
Medical subject headings
- Heme
- MicroRNAs
- RNA-Binding Proteins
- Ribonuclease III