Human Serine/Arginine-rich Splicing Factor 1, SFRS1 ELI

Plays a role in preventing exon skipping, ensuring the accuracy of splicing and regulating alternative splicing.

Interacts with other spliceosomal components, via the RS domains, to form a bridge between the 5'- and 3'-splice site binding components, U1 snRNP and U2AF.

Can stimulate binding of U1 snRNP to a 5'-splice site-containing pre-mRNA.

Binds to purine-rich RNA sequences, either the octamer, 5'-RGAAGAAC-3' (r=A or G) or the decamers, AGGACAGAGC/AGGACGAAGC.

Binds preferentially to the 5'-CGAGGCG-3' motif in vitro.

Three copies of the octamer constitute a powerful splicing enhancer in vitro, the ASF/SF2 splicing enhancer (ASE) which can specifically activate ASE-dependent splicing.

Isoform ASF-2 and isoform ASF-3 act as splicing repressors.

May function as export adapter involved in mRNA nuclear export through the TAP/NXF1 pathway.