HnRNP M is a splicing regulatory factor that binds to the auxiliary RNA cis-element ISE/ISS-2 which promotes splicing of exon IIIb and silencing of exon IIIC in the fibroblast growth factor receptor 2 (FGFR2) . By binding to ISE/ISS-3, HnRNP M plays a role in the regulation of alternative splicing in FGFR2 as it induces exon skipping and promotes exon inclusion .
Heterogeneous nuclear ribonucleoproteins (hnRNPs) bind directly to nascent RNA polymerase II transcripts and play an important role in both transcript-specific packaging and alternative splicing of pre-mRNAs [PUBMED:8441656]. hnRNP M proteins are an abundant group of hnRNPs that have been shown to bind avidly to poly(G) and poly(U) RNA homopolymers [PUBMED:8441656]. hnRNP M family members are able to induce exon skipping and promote exon inclusion, suggesting that the proteins may broadly contribute to the fidelity of splice site recognition and alternative splicing regulation [PUBMED:17959601].