Transcriptome-wide identification of LIN28A targets in mouse embryonic stem cell (A3-1) [Illumina Seq]

LIN28A is a highly-conserved RNA-binding protein which is known to be involved in embryonic development, stem cell maintenance and proliferation. LIN28A is expressed in various types of cancer, and they are associated with advanced tumor malignancy. In embryonic stem cell, LIN28A specifically binds to let-7 precursors to suppress biogenesis of the let-7 microRNA family. In addition, Lin28 was reported to bind several mRNAs such as Oct4, cyclin A/B and histone H2A to activate their translation. For comprehensive understanding of the interaction between LIN28A and their target RNAs, we exploited UV-crosslinking and immunoprecipitation (CLIP) to capture their in vivo binding to target RNAs. LIN28A-binding RNAs were identified in a mouse embryonic stem cell line using multiple monoclonal and polyclonal antibodies. The result shows that LIN28A preferentially binds to let-7 precursors through GGAG binding motif, which is consistent with our previous results. We also identified that LIN28A binding is enriched in a certain subset of mRNAs. To understand the function of the novel LIN28A-mRNA binding, we carried out ribosome profiling from LIN28A-depleted mouse embryonic stem cells.