Activation of the stress-activated protein kinase JNK in response to herpes simplex virus-1 infection coordinates transition of BRD4 from chromosome association to transcription elongation

(199 words) The c-Jun N-terminal kinase (JNK) signaling pathway is required for herpes simplex virus 1 lytic infection and reactivation from latency. JNK signaling regulates cellular processes in response to stress through transcriptional regulation. However, the mechanisms by which JNK regulates HSV-1 infection are less defined. We show here that HSV-1 infection triggers BRD4 transition from chromosome association to transcriptional regulation for viral infection. Specifically, HSV-1 infection induces JNK activation which mediates redistribution of BRD4, an epigenetic reader protein, from chromatin-targeting to association with proteins of transcriptional regulation. BRD4 transitions to viral infection regulation by complexing with P-TEFb, a positive transcription elongation factor, and association with viral DNA. Genetic ablation or perturbation of JNK with chemical inhibitors or siRNA leads to impediment of BRD4 release and inhibition of HSV-1 infection. Both chemotherapeutic agents and irradiation are known to promote JNK activation and HSV reactivation. We show further that JNK agonist or chemotherapeutic agents known to activate JNK have the ability to enhance HSV-1 infection. Our study reveals a novel mechanism by which JNK regulates HSV-1 infection through stress-induced BRD4 function transition from host chromosome association to viral gene expression. The work links recurrent HSV infection by chemotherapeutic agents to JNK activation.