The viral oncoproteins Tax and HBZ reprogram the cellular mRNA splicing landscape

While viral infections are known to hijack the transcription and translation of the host cell, the extent to which encoded viral proteins coordinate these perturbations remains unclear. Here we demonstrate that the oncoviral proteins Tax and HBZ interact with specific components of the spliceosome machinery, including the U2 auxiliary factor large subunit (U2AF2), and the complementary factor for APOBEC-1 (A1CF), respectively. Tax and HBZ perturb the splicing landscape in T-cells by altering cassette exons in opposing manners, with Tax inducing exon inclusion while HBZ induces exon exclusion. Among Tax- and HBZ-dependent splicing changes, we identify events that are also altered in Adult T cell leukemia (ATL) patients, and in well-known cancer census genes. Our interactome mapping approach, applicable to other viral oncogenes, has identified spliceosome perturbation as a novel mechanism coordinately used by Tax and HBZ to reprogram the transcriptome. HighlightsO_LITax and HBZ interact with RNA-binding proteins as well as transcription factors C_LIO_LIHTLV-1 encoded proteins Tax and HBZ alter the splicing landscape in T-cells C_LIO_LITax and HBZ expression affect alternative splicing of 33 and 63 cancer genes, respectively C_LIO_LIOpposing roles for Tax and HBZ in deregulation of gene expression C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=158 HEIGHT=200 SRC="FIGDIR/small/427104v1_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@b5f6f0org.highwire.dtl.DTLVardef@6725b3org.highwire.dtl.DTLVardef@1dc32fborg.highwire.dtl.DTLVardef@19728c6_HPS_FORMAT_FIGEXP M_FIG C_FIG