Abstract
Affinity chromatography was used to identify cellular proteins that interact with the herpes simplex virus (HSV) tegument protein VP22. Among a small set of proteins that bind specifically to VP22, we identified TAF-I (template-activating factor I), a chromatin remodelling protein and close homologue of the histone chaperone protein NAP-1. TAF-I has been shown previously to promote more ordered transfer of histones to naked DNA through a direct interaction with histones. TAF-I, as a subunit of the INHAT (inhibitor of acetyltransferases) protein complex, also binds to histones and masks them from being substrates for the acetyltransferases p300 and PCAF. Using in vitro assays for TAF-I activity in chromatin assembly, we show that VP22 inhibits nucleosome deposition on DNA by binding to TAF-I. We also observed that VP22 binds non-specifically to DNA, an activity that is abolished by TAF-I. However, the presence of VP22 does not affect the property of INHAT in inhibiting the histone acetyltransferase activity of p300 or PCAF in vitro. We speculate that this interaction could be relevant to HSV DNA organization early in infection, for example, by interfering with nucleosomal deposition on the genome. Consistent with this possibility was the observation that overexpression of TAF-I in transfected cells interferes with the progression of HSV-1 infection.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Acetylation
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Acetyltransferases / antagonists & inhibitors*
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Acetyltransferases / metabolism
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Acetyltransferases / pharmacology
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Amino Acid Sequence
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Animals
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COS Cells
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Cell Cycle Proteins / metabolism
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Chromatin / metabolism
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Chromosomal Proteins, Non-Histone / biosynthesis
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Chromosomal Proteins, Non-Histone / genetics
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Chromosomal Proteins, Non-Histone / metabolism*
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DNA-Binding Proteins / metabolism
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HeLa Cells
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Herpesvirus 1, Human / metabolism*
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Histone Acetyltransferases
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Histone Chaperones
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Histones / chemistry
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Histones / metabolism*
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Humans
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Molecular Sequence Data
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Nucleosomes / metabolism*
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Protein Binding
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Saccharomyces cerevisiae Proteins / metabolism
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Sequence Alignment
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Templates, Genetic*
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Transcription Factors / biosynthesis
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Transcription Factors / genetics
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Transcription Factors / metabolism*
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Transfection
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Viral Proteins / genetics
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Viral Proteins / metabolism*
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Virus Replication
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p300-CBP Transcription Factors
Substances
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Cell Cycle Proteins
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Chromatin
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Chromosomal Proteins, Non-Histone
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DNA-Binding Proteins
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Histone Chaperones
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Histones
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ICP35 protein, Human herpesvirus 1
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Nucleosomes
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SET protein, human
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Saccharomyces cerevisiae Proteins
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Transcription Factors
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Viral Proteins
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Acetyltransferases
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Histone Acetyltransferases
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p300-CBP Transcription Factors
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p300-CBP-associated factor