Drosha–DGCR8 microprocessor complex (Microprocessor) (Microprocessor)

The Drosha–DGCR8 microprocessor complex is a nuclear heterotrimeric assembly essential for the primary step of microRNA (miRNA) biogenesis (NIH, 2020). It consists of one molecule of the Class 2 ribonuclease III enzyme Drosha and two molecules of the RNA-binding protein DGCR8 (DiGeorge syndrome critical region 8) (Wikipedia, 2024). Within the complex, DGCR8 acts as a molecular anchor and ruler, recognizing the junction between the single-stranded and double-stranded regions of primary miRNA (pri-miRNA) transcripts and positioning Drosha to execute a precise endonucleolytic cleavage (UniProt, 2024). This process releases a ~70-nucleotide precursor miRNA (pre-miRNA) hairpin, which is subsequently exported to the cytoplasm for further maturation by Dicer (PubMed, 2011). Beyond miRNA processing, the complex regulates the stability of various messenger RNAs (mRNAs) and small nucleolar RNAs (snoRNAs), often through an auto-regulatory feedback loop where it cleaves its own components' transcripts (NIH, 2012). Dysregulation of the microprocessor complex is linked to numerous pathologies, including various cancers where it can act as either an oncogene or a tumor suppressor, and DiGeorge syndrome, which is characterized by the deletion of the DGCR8 gene (MDPI, 2024). Therapeutic strategies targeting the complex include small molecule inhibitors like acriflavine and enhancers like enoxacin, aimed at modulating miRNA-mediated gene silencing in disease contexts (PubMed, 2019).

Other names

Microprocessor complexDrosha-DGCR8 complexPasha-Drosha complexRNASEN-DGCR8 complex

Inhibition of endonucleolytic cleavage, enhancement of miRNA processing, and disruption of protein-protein or protein-RNA interactions.