Enhancer activation by the oncogenic herpesvirus KSHV tethering protein LANA

Higher order genome structure influences the transcriptional regulation of cellular genes through the juxtaposition of regulatory elements, such as enhancers, close to promoters of target genes. While enhancer activation has emerged as an important facet of Kaposi's sarcoma-associated herpesvirus (KSHV) biology, mechanisms controlling enhancer-target gene expression remain obscure. Here, we discover that the KSHV genome tethering protein latency-associated nuclear antigen (LANA) potentiates enhancer-target gene expression in primary effusion lymphoma (PEL), a highly aggressive B cell lymphoma causally associated with KSHV. Genome-wide analyses demonstrate increased levels of enhancer RNA transcription as well as activating chromatin marks at LANA bound enhancers. 3D-genome conformation analyses identified genes critical for latency and tumorigenesis as targets of LANA occupied enhancers, and LANA depletion results in their downregulation. These findings reveal a previously unknown mechanism in enhancer-gene coordination and describe a role through which the main KSHV tethering protein regulates essential gene expression in PEL. Overall design: This experiment employ HiChIP, CUT&RUN, ATACme and RNAseq profile systematically how KSHV encoded protein LANA regulate enhancer activity and gene expression in latent TREx-BCBL1-RTA and BC3 cells.