RNA recognition motif 1 (RRM1) found in epithelial splicing regulatory protein 1 (ESRP1) and similar proteins
This subgroup corresponds to the RRM1 of ESRP1, also termed RNA-binding motif protein 35A (RBM35A), which has been identified as an epithelial cell type-specific regulator of fibroblast growth factor receptor 2 (FGFR2) splicing. It is required for expression of epithelial FGFR2-IIIb and the regulation of CD44, CTNND1 (p120-Catenin) and ENAH (hMena) splicing. It enhances epithelial-specific exons of CD44 and ENAH, silences mesenchymal exons of CTNND1, or both within FGFR2. Additional research indicated that ESRP1 functions as a tumor suppressor in colon cancer cells. It may be involved in posttranscriptional regulation of various genes by exerting a differential effect on protein translation via 5' untranslated regions (UTRs) of mRNAs. ESRP1 contains three RNA recognition motifs (RRMs), also termed RBDs (RNA binding domains) or RNPs (ribonucleoprotein domains).