ESRG regulates alternative splicing of TCF3 to maintain hESCs self-renewal and pluripotency
Elucidating the mechanism of self-renewal and pluripotency maintenance of human embryonic stem cells (hESCs) is of great significance in basic research and clinical applications. Long non-coding RNAs (lncRNAs) have been shown to play a key role in the self-renewal and pluripotency maintenance of hESCs. We previously reported that the lncRNA ESRG, which is highly expressed in undifferentiated hESCs, can interact with the replication licensing factor MCM2 and inhibit the p53 pathway to maintain the self-renewal and pluripotency of hPSCs. In addition to MCM2, RNA pull-down mass spectrometry showed that ESRG could also bind to other proteins, among which heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) attracted our attention. In this study, we show that HNRNPA1 can maintain self-renewal and pluripotency of hESCs. ESRG binds to and stabilizes HNRNPA1 protein through the ubiquitin-proteasome pathway. In addition, knockdown of ESRG or HNRNPA1 resulted in alternative splicing of TCF3, which originally and primarily encodes E12, to mainly encode E47 and inhibit CDH1 expression. HNRNPA1 could rescue the biological function changes of hESCs caused by ESRG knockdown or overexpression. Our results suggest that ESRG regulates the alternative splicing of TCF3 to affect CDH1 expression and maintain hESCs self-renewal and pluripotency by binding and stabilizing HNRNPA1 protein. This study lays a good foundation for exploring the new molecular regulatory mechanism by which ESRG maintains hESCs self-renewal and pluripotency. Overall design: Gene Expression Profiling of human embryonic stem cells (H9) treated by siControl and siHNRNPA1 for 48h were characterized using RNA-seq.