Alternative splicing generates mRNA isoforms with diverse cytoplasmic fates. Alternative splicing expands the protein coding capacity of human genes (upper panel). Alternative splicing can also be coupled to nonsense mediated decay (AS-NMD, middle panel). This mechanism can attenuate gene expression post-transcriptionally by producing unstable PTC-containing isoforms. In this paper, we present a novel mode of splicing-based gene regulation linking alternative splicing and translational control (AS-TC, lower panel) of the resultant mRNA isoforms. Our data suggest the intriguing hypothesis that alternative splicing of both coding and noncoding exons alters the cis-regulatory landscape of mRNA isoforms leading to different levels of polyribosome association.
