T he NF-κB protein p65 / R elA pla y s a pivotal role in coordinating gene expression in response to diverse stimuli, including viral infections. At the chromatin le v el, p65 / R elA regulates gene transcription and alternative splicing through promoter enrichment and genomic e x on occupancy, respectiv ely. T he intricate w a y s in which p65 / R elA simultaneously go v erns these functions across various genes remain to be fully elucidated. In this study, we employed the HTLV-1 Tax oncoprotein, a potent activator of NF-κB, to investigate its influence on the three-dimensional organization of the genome, a k e y f actor in gene regulation. We disco v ered that Tax restr uct ures the 3D genomic landscape, bringing together genes based on their regulation and splicing patterns. Notably, w e f ound that the Tax-induced gene-gene contact between the two master genes NFKBIA and RELA is associated with their respective changes in gene expression and alternative splicing. Through dCas9-mediated approaches, we demonstrated that NFKBIA-RELA interaction is required for alternative splicing regulation and is caused by an intragenic enrichment of p65 / RelA on RELA . Our findings shed light on new regulatory mechanisms upon HTLV-1 Tax and underscore the integral role of p65 / RelA in coordinated regulation of NF-κB-responsive genes at both transcriptional and splicing levels in the context of the 3D genome.

NF-kB p65/RELA TAX 3D Chromatin Dynamics Coordinated Gene-to-Gene Transcription and Alternative Splicing