TY - JOUR T1 - The human leukemia virus HTLV-1 alters the structure and transcription of host chromatin <em>in cis</em> JF - bioRxiv DO - 10.1101/277335 SP - 277335 AU - Anat Melamed AU - Hiroko Yaguchi AU - Michi Miura AU - Aviva Witkover AU - Tomas W Fitzgerald AU - Ewan Birney AU - Charles R M Bangham Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/03/07/277335.abstract N2 - Chromatin looping controls gene expression by regulating promoter-enhancer contacts, the spread of epigenetic modifications, and the segregation of the genome into transcriptionally active and inactive compartments. We studied the impact on the structure and expression of host chromatin by the human retrovirus HTLV-1. We show that HTLV-1 disrupts host chromatin structure by forming loops between the provirus and the host genome; certain loops depend on the critical chromatin architectural protein CTCF, which we recently showed binds to the HTLV-1 provirus. Finally, we show that the provirus causes two distinct patterns of abnormal transcription of the host genome in cis: bidirectional transcription in the host genome immediately flanking the provirus, and clone-specific transcription in cis at non-contiguous loci up to &gt;300 kb from the integration site. We conclude that HTLV-1 causes insertional mutagenesis up to the megabase range in the host genome in &gt;104 persistently-maintained HTLV-1+ T-cell clones in vivo. ER -