Epithelial Splicing Regulatory Protein 1 (ESRP1)

ESPR1 is an epithelial cell-type-specific splicing regulator. Comparison of ESRP orthologs in diverse species showed significant sequence conservation within the RRM domains, particularly RRM1. In situ hybridization of neonatal and adult mice revealed distinct epithelial-specific expression of Esrp1 in diverse tissues and organs, with highest expression in skin and gastrointestinal epithelia. Microarray analysis revealed that cell lines classified as epithelial expressed higher levels of ESRP1 and/or ESRP2 than cell lines classified as mesenchymal. Depletion of ESRP1 and ESRP2 in a human prostate epithelial cell line via RNA interference (RNAi) caused a significant switch from exon IIIb to exon IIIc splicing in the endogenous FGFR2 transcript. Rescue experiments with mouse cDNAs showed that FGFR2-IIIb splicing was more dependent on ESRP1 than ESRP2.