The subunit DGCR8 is localized to the
cell nucleus and is required for
microRNA (miRNA) processing. It binds to the other subunit
Drosha, an
RNase III enzyme, 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. 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. While DGCR8 is known to function in microRNA biogenesis, this activity is not required for DGCR8-dependent removal of UV-induced photoproducts.
Nucleotide excision repair is also needed for repair of oxidative DNA damage due to
hydrogen peroxide (), and DGCR8 depleted cells are sensitive to . == References ==