Related Experiment Video
Updated: Dec 14, 2025

Temporal Analysis of the Nuclear-to-cytoplasmic Translocation of a Herpes Simplex Virus 1 Protein by Immunofluorescent Confocal Microscopy
Published on: November 4, 2018
The HSV-1 ICP4 Transcriptional Auto-Repression Circuit Functions as a Transcriptional "Accelerator" Circuit
Sonali Chaturvedi1,2, Ruth Engel2, Leor Weinberger1,2,3,4
1Gladstone Institute of Virology and Immunology, University of California, San Francisco, San Francisco, CA, United States.
Abstract:
Herpes simplex virus-1 (HSV-1) is a significant human pathogen. Upon infection, HSV-1 expresses its immediate early (IE) genes, and the IE transcription factor ICP4 (infectious cell protein-4) plays a pivotal role in initiating the downstream gene-expression cascade. Using live-cell time-lapse fluorescence microscopy, flow cytometry, qPCR, and chromatin immunoprecipitation, we quantitatively monitored the expression of ICP4 in individual cells after infection. We find that extrinsic stimuli can accelerate ICP4 kinetics without increasing ICP4 protein or mRNA levels. The accelerated ICP4 kinetics-despite unchanged steady-state ICP4 protein or mRNA level-correlate with increased HSV-1 replicative fitness. Hence, the kinetics of ICP4 functionally mirror the kinetics of the human herpesvirus cytomegalovirus IE2 "accelerator" circuit, indicating that IE accelerator circuitry is shared among the alpha and beta herpesviruses. We speculate that this circuit motif is a common evolutionary countermeasure to throttle IE expression and thereby minimize the inherent cytotoxicity of these obligate viral transactivators.
More Related Videos
Related Concept Videos
Co-activators and Co-repressors
Co-activators and Co-repressors
RNA Polymerase II Accessory Proteins
Eukaryotic Transcription Activators
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
Prokaryotic Transcriptional Activators and Repressors
Transcription of prokaryotic...
Prokaryotic Transcriptional Activators and Repressors

