RNA-binding protein that acts as a pre-mRNA splicing factor. Acts by promoting exon inclusion via regulation of exon cassette splicing (By similarity). 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 (By similarity).