A Novel role for GSK3B as a modulator of Drosha Microprocessor activity and microRNA biogenesis
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ABSTRACT: Regulation of microRNA (miR) biogenesis is complex and stringently controlled. Here we identify the kinase GSK3B as an important modulator of global miR biogenesis at microprocessor level. Repression of GSK3B activity reduces Drosha activity towards pri-miRs, leading to accumulation of unprocessed pri-miRs and reduction of pre-miRs and mature miRs without altering levels or cellular localisationof miR biogenesisproteins. Conversly, GSK3B activation increases Drosha activityand mature miR accumulation. GSK3B achieves this through promoting Drosha:cofactor and Drosha:pri-miR interactions: it binds to DGCR8 and p72 in the Microprocessor, an effect dependent of RNA. Indeed GSK3B itself can immunoprecipitate pri-miRs, suggesting possible RNA binding capacity. Kinase assays identify the mechanism for GSK3B-enhansed Drosha activity, which requires GSK3B nuclear localisation, as phosphorylation of Drosha at s300 and/or s302 confirmed by enhanced Drosha activity and association with cofactors, and increased abundance of mature microRNAs in the presence of phospho-mimetic Drosha. Functional implicatons of GSK3B-enhanced miR biogenesis are illustrated by increased levels of GSK3B-upregulatd miR targets following GSK3B inhibition. These data, the first link GSK3B with the miR cascade in humans, hilight a novel pro-biogenesis role for GSK3B in increasing miR biogenesis as a component of the Microprocessor complex with wide ranging consiquences.
ORGANISM(S): Homo sapiens
PROVIDER: GSE81141 | GEO | 2016/05/20
SECONDARY ACCESSION(S): PRJNA320721
REPOSITORIES: GEO
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