spliceostatin-a and herboxidiene

Pladienolide, herboxidiene and spliceostatin have been identified as splicing modulators that target SF3B1 in the SF3b subcomplex. Here we report that PHF5A, another component of this subcomplex, is also targeted by these compounds. Mutations in PHF5A-Y36, SF3B1-K1071, SF3B1-R1074 and SF3B1-V1078 confer resistance to these modulators, suggesting a common interaction site. RNA-seq analysis reveals that PHF5A-Y36C has minimal effect on basal splicing but inhibits the global action of splicing modulators. Moreover, PHF5A-Y36C alters splicing modulator-induced intron-retention/exon-skipping profile, which correlates with the differential GC content between adjacent introns and exons. We determine the crystal structure of human PHF5A demonstrating that Y36 is located on a highly conserved surface. Analysis of the cryo-EM spliceosome B

Topics: Adenosine; Alternative Splicing; Carrier Proteins; Cell Proliferation; Cell Survival; Cryoelectron Microscopy; Crystallography, X-Ray; Epoxy Compounds; Exons; Fatty Alcohols; HCT116 Cells; Humans; Introns; Macrolides; Mass Spectrometry; Mutagenesis, Site-Directed; Mutation; Myeloid Cell Leukemia Sequence 1 Protein; Phosphoproteins; Protein Binding; Protein Conformation; Pyrans; Recombinant Proteins; RNA Interference; RNA Splicing Factors; RNA-Binding Proteins; Sequence Analysis, RNA; Spiro Compounds; Spliceosomes; Trans-Activators