Fig. 9: Molecular mechanism of RBM39 autoregulation.
From: Molecular basis of RNA-binding and autoregulation by the cancer-associated splicing factor RBM39
a Schematic representation of the RBM39 poison exon (exon 2b) and the cis-acting RNA elements governing its inclusion. In the absence of RBM39, the splice sites of the poison exon are not recognised efficiently. The proteins labelled with 1 and 2 correspond to U2AF1 and U2AF2, respectively. b When the RBM39 binding motif BS1 is mutated, U2AF2 binds to the 3′-ss and promotes poison exon inclusion independently of RBM39. c In the wild-type situation, RBM39 contacts the 3′-ss via RRM2 and stabilises the U2 snRNP on the branchpoint via RRM3 and the RS domain. RRM1 interacts with an RNA stem loop, which could be located either in the pre-mRNA (e.g. SLi) or in a spliceosomal RNA (e.g. U1 snRNA).
