Skip to main content
. 2021 Feb 8;17(3):807–817. doi: 10.7150/ijbs.55120

Figure 2.

Figure 2

Molecular mechanisms of hnRNPs included in the life cycle of stem cells. (1) hnRNPs bind directly to mRNAs or lncRNAs to regulate mRNA stability. For example, hnRNPI binds to the lncRNA Pnky and then interacts with the mRNA of ID2 to regulate its stability. (2) hnRNPs induce the alternative splicing of mRNAs. For instance, hnRNPF/H can regulate alternative splicing of TCF3, resulting in two isoforms E12and E47 that play different roles in the life cycle of stem cells. (3) hnRNPs epigenetically regulate gene expression to affect embryonic development. hnRNPs affect the transcription of surrounding mRNAs through m6A modification. Their own expression is also regulated by this kind of RNA modification. For example, hnRNPA2/B1 is regulated by METTL3-dependent m6A methylation to maintain self-renewal of stem cells in mouse embryo development. Moreover, hnRNPs bind with Xist RNA and participate in chromatin modifications. For example, hnRNPK recruits a transcriptional silencing complex with Xist RNA to induce the formation of heterochromatin. (4) hnRNPs regulate telomerase activity and telomere length in stem cells. For example, hnRNPF/H forms a multimeric complex with hTERC, which contributes to telomere addition to chromosome ends and maintenance of telomere length.