Transcriptional coactivator HCF-1 couples the histone chaperone Asf1b to HSV-1 DNA replication components.
The cellular transcriptional coactivator HCF-1 interacts with numerous transcription factors as well as other coactivators and is a component of multiple chromatin modulation complexes. The protein is essential for the expression of the immediate early genes of both herpes simplex virus (HSV) and varicella zoster virus and functions, in part, by coupling chromatin modification components including the Set1 or MLL1 histone methyltransferases and the histone demethylase LSD1 to promote the installation of positive chromatin marks and the activation of viral immediately early gene transcription. Although studies have investigated the role of HCF-1 in both cellular and viral transcription, little is known about other processes that the protein may be involved in. Here we demonstrate that HCF-1 localizes to sites of HSV replication late in infection. HCF-1 interacts directly and simultaneously with both HSV DNA replication proteins and the cellular histone chaperone Asf1b, a protein that regulates the progression of cellular DNA replication forks via chromatin reorganization. Asf1b localizes with HCF-1 in viral replication foci and depletion of Asf1b results in significantly reduced viral DNA accumulation. The results support a model in which the transcriptional coactivator HCF-1 is a component of the HSV DNA replication assembly and promotes viral DNA replication by coupling Asf1b to DNA replication components. This coupling provides a novel function for HCF-1 and insights into the mechanisms of modulating chromatin during DNA replication.
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bld 4-131, 4 Center Drive, Bethesda, MD 20892, USA.
Hua
H
Peng
Mauricio L
ML
Nogueira
Jodi L
JL
Vogel
Thomas M
TM
Kristie
D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002522:Chlorocebus aethiops; D004261:DNA Replication; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000254:growth & development*; D006657:Histones / Q000378:metabolism; D051863:Host Cell Factor C1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D008856:Microscopy, Fluorescence; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D034622:RNA Interference; D020798:Two-Hybrid System Techniques; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
C491640:ASF1B protein, human; D018797:Cell Cycle Proteins; D004279:DNA, Viral; C497692:HCFC1 protein, human; D006657:Histones; D051863:Host Cell Factor C1; D018832:Molecular Chaperones; D014764:Viral Proteins