Seminar: Circular non-coding RNAs – new type of players in gene regulation.
2012-05-23: by Jørgen Kjems, Department of Molecular Biology, Aarhus University on May 23rd at 11.15-12.15 in auditorium A1-01.14, Nordre sti 2, 1st floor, University of Copenhagen, LIFE, Frederiksberg.
Registration is not necessary, refreshment will be served.
Over the last decade it has become evident that non-coding RNA by fare exceed coding RNA in the vertebrate genome and that many of them play key roles in controlling gene expression. Not surprising alterations in non-coding RNA expression also gives raise to diseases and can in fact be used as robust biomarkers for disease prognosis and diagnosis. One of the best studied groups of regulatory non-coding RNAs are microRNAs (miRNAs) that typically bind to the 3’ UTR of target mRNAs in the cytoplasm, resulting in mRNA destabilization and translational repression. We find that miRNAs can also regulate gene expression by targeting non-coding antisense transcripts in human cells. In one example we show that miRNA can accumulates in the nucleus where it directs cleavage of circular antisense transcripts resulting in a concomitant decrease in sense mRNA levels, independently of heterochromatin formation. Surprisingly, circular RNA has more global effects on gene expression then just regulating expression of protein from complimentary DNA strand. We have recently unraveled a whole new layer of regulation where circular RNA appears to regulate many other genes through a intricate network of other non-coding RNA. The circular RNA appears to accumulate to extremely high levels in a subset of brain cells where it has the potential of regulating prominent genes involved in the unset of Parkinson disease, Alzheimer disease and cancer.