Action model of RBM10. (A) AS events promoted by RBM10. RBM10 promotes skipping of target exons in substrate pre-mRNAs (1). In addition, it may promote other AS events (2) – (6), albeit less frequently. Exons, introns, and splice choices are illustrated using boxes, thick lines, and angled lines, respectively. (B) Association of RBM10 with the vicinity of the 3′-splice site (ss) of a target cassette exon in the spliceosome A complex. RBM10 brings about AS (skipping) of the cassette exon in association with the 35- and 65-kDa subunits of splicing factor U2AF and U2 snRNA of U2 snRNP. (C) Model of RBM10-mediated skipping of a cassette exon. RBM10 is believed to interfere with the 3′- and 5′-ss recognition and/or splice site pairing of the cassette exon, and to enhance the pairing of the distal 5′- and 3′-ss (in boldface). Exons, introns, and exon skipping by pairing of distal splice sites are indicated using boxes, thick horizontal lines, and an angled line, respectively.