Figure 7.

The role of MALAT1 in the regulation of alternative splicing. A. MALAT1 controls the phosphorylation of SRSF1 proteins in the nucleus, including the MALAT1-interacting SRSF1. Phosphorylated SRSF1 is accumulated in nuclear speckles (NS). Dephosphorylated SRSF1 promotes its interaction with mRNAs and transport into the cytoplasm. Here, the spliced mRNA is either translated by the ribosome or degradation by the non-sense mediated decay (NMD) machinery. B. MALAT1 binds to (hijacks) SFPQ, disrupting the SFPQ/PTBP2 complex. This results in the pro-oncogenic isoform of PTBP2, promoting tumour growth.