SPT6 interacts with NSD2 and facilitates interferon-stimulated transcription

SPT6, encoded by the SUPT6H in humans and Supt6 in mice, respectively, is a conserved histone chaperone that interacts with RNA polymerase II and participates in transcription elongation. However, the question of how SPT6 comes into play in transcriptional activation upon signaling, particularly in mammalian cells, has remained elusive. We investigated the contribution of SPT6 to interferon beta (IFNbeta) induced transcription in mouse NIH3T3 cells. IFNbeta triggers rapid and high level transcription of many IFN-stimulated genes (ISGs). We report here that SPT6 is recruited to ISGs after IFN stimulation. This recruitment was dependent on the interaction with the methyltransferase, NSD2. Further, siRNA-based SPT6 knockdown reduced levels of ISG activation. RNA-Seq analysis showed that SPT6 knockdown diminished about 50% of ISGs whose induction levels were higher than those unaffected by SPT6 knockdown. Under the tested conditions, SPT6 knockdown did not measurably change expression of constitutively expressed genes. This report highlights that SPT6 is recruited in a stimulus-dependent manner and elicits a major impact on signal induced transcription. Overall design: RNA-seq of NIH3T3 cells.

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Ouda R, Sarai N, Nehru V, Patel MC, Debrosse M, Bachu M, Chereji RV, Eriksson PR, Clark DJ, Ozato K