ECD, a novel U5 snRNA binding protein regulates RNA splicing [RNA-Seq, RIP-Seq]

More recently, ECD has been implicated in RNA biogenesis through its regulatory effects on mRNA nuclear export and RNA splicing. In the current study, we identified the mechanism of ECD’s function in RNA splicing.

We demonstrate a novel role of ECD as an RNA-binding protein and, through mutational analyses, we show that it utilizes its N-terminal region to interact with RNAs. By employing unbiased approaches such as eCLIP-seq and RNA-seq analyses in hTERT-immortalized mammary epithelial cells (76NTERT), we demonstrate that ECD directly binds to RNA and predominantly utilizes its RNA-binding abilities to regulate RNA splicing. This regulation occurs either through direct binding of ECD to RNA sequences located near splicing sites, one of the top ECD binding motifs identified being purine-rich exonic splicing enhancers or by influencing the biogenesis of the U5 small nuclear ribonucleoprotein particle (U5 snRNP) complex via its direct interaction with U5 snRNA.