RNA-binding protein that acts as a pre-mRNA splicing factor (  ). Acts by promoting exon inclusion via regulation of exon cassette splicing . Also acts as a transcriptional coactivator for steroid nuclear receptors ESR1/ER-alpha and ESR2/ER-beta, and JUN/AP-1, independently of the pre-mRNA splicing factor activity (By similarity).
Subcellular locations: Nucleus speckle
Concentrated in nuclear speckles . Colocalizes with the core spliceosomal snRNP proteins .
Widely expressed. Highly expressed in pancreas, skeletal muscle, lung and brain . Expressed at intermediate level in kidney, liver and heart .