DGCR8 is localized to the cell nucleus and is required for microRNA (miRNA) processing. It binds to Drosha, an RNase IIIenzyme, to form the Microprocessor complex that cleaves a primary transcript known as pri-miRNA to a characteristic stem-loop structure known as a pre-miRNA, which is then further processed to miRNA fragments by the enzyme Dicer. DGCR8 contains an RNA-binding domain and is thought to bind pri-miRNA to stabilize it for processing by Drosha.[6]
DGCR8 is also required for some types of DNA repair. Removal of UV-induced DNA photoproducts, during transcription coupled nucleotide excision repair (TC-NER), depends on JNK phosphorylation of DGCR8 on serine 153.[7] While DGCR8 is known to function in microRNA biogenesis, this activity is not required for DGCR8-dependent removal of UV-induced photoproducts.[7]Nucleotide excision repair is also needed for repair of oxidative DNA damage due to hydrogen peroxide (H2O2), and DGCR8 depleted cells are sensitive to H2O2.[7]
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