LIN28 binds messenger RNAs at GGAGA motifs and regulates splicing factor abundance.
|Title||LIN28 binds messenger RNAs at GGAGA motifs and regulates splicing factor abundance.|
|Publication Type||Journal Article|
|Year of Publication||2012|
|Authors||Wilbert ML, Huelga SC, Kapeli K, Stark TJ, Liang TY, Chen SX, Yan BY, Nathanson JL, Hutt KR, Lovci MT, Kazan H, Vu AQ, Massirer KB, Morris Q, Hoon S, Yeo GW|
|Date Published||2012 Oct 26|
|Keywords||Alternative Splicing, Binding Sites, Embryonic Stem Cells, Gene Expression Regulation, Developmental, HEK293 Cells, Humans, Nucleotide Motifs, RNA, Messenger, RNA-Binding Proteins|
LIN28 is a conserved RNA-binding protein implicated in pluripotency, reprogramming, and oncogenesis. It was previously shown to act primarily by blocking let-7 microRNA (miRNA) biogenesis, but here we elucidate distinct roles of LIN28 regulation via its direct messenger RNA (mRNA) targets. Through crosslinking and immunoprecipitation coupled with high-throughput sequencing (CLIP-seq) in human embryonic stem cells and somatic cells expressing exogenous LIN28, we have defined discrete LIN28-binding sites in a quarter of human transcripts. These sites revealed that LIN28 binds to GGAGA sequences enriched within loop structures in mRNAs, reminiscent of its interaction with let-7 miRNA precursors. Among LIN28 mRNA targets, we found evidence for LIN28 autoregulation and also direct but differing effects on the protein abundance of splicing regulators in somatic and pluripotent stem cells. Splicing-sensitive microarrays demonstrated that exogenous LIN28 expression causes widespread downstream alternative splicing changes. These findings identify important regulatory functions of LIN28 via direct mRNA interactions.
|Alternate Journal||Mol. Cell|