Role of Factor Acetylation in the Regulation of HIV Transcription

Information

  • Research Project
  • 10457576
  • ApplicationId
    10457576
  • Core Project Number
    R37AI083139
  • Full Project Number
    3R37AI083139-12S1
  • Serial Number
    083139
  • FOA Number
    PA-18-484
  • Sub Project Id
  • Project Start Date
    7/15/2009 - 14 years ago
  • Project End Date
    6/30/2024 - 9 days from now
  • Program Officer Name
    MCDONALD, DAVID JOSEPH
  • Budget Start Date
    9/3/2021 - 2 years ago
  • Budget End Date
    6/30/2022 - a year ago
  • Fiscal Year
    2021
  • Support Year
    12
  • Suffix
    S1
  • Award Notice Date
    9/2/2021 - 2 years ago

Role of Factor Acetylation in the Regulation of HIV Transcription

ABSTRACT Factor acetylation is a recognized epigenetic process governing HIV latency, but the silencing mechanisms associated with acetylated factors at the latent HIV promoter are not defined. The central hypothesis of this proposal is that acetyl-lysine reader proteins, such as the bromo- and ET domain-containing BRD4, and the Regulation of Nuclear Pre-MRNA Domain Containing 1 (RPRD1) proteins are critical regulators of latent HIV infection. This hypothesis is based on our recent data showing that the short isoform of the BRD4 protein (sBET), together with the BAF chromatin-remodeling complex, suppresses transcription of HIV and of endogenous retroviruses, supporting a model in which the sBET-BAF complex senses and silences genome-invading retroviruses (1). This model is supported by findings implicating another complex of bromodomain and chromatin-remodeling proteins, the ZYMND8-NuRD complex, in gene silencing during DNA damage (2-4). We further showed that RPRD1 proteins?without bromodomains?bind acetylated lysines (K7ac) within the RNA polymerase II, a mark highly enriched at the latent HIV LTR (5, 6). The central hypothesis will be tested in three specific aims: 1) To define the role of the sBET-BAF complex in genome surveillance. The working hypothesis is that sBET-BAF, similar to ZMYND8-NURD, senses double-strand DNA breaks caused by integrating retroviruses and silences gene expression by actively positioning a repressive nucleosome (nuc-1). We will test the hypothesis by using a dual-fluorescent clone of HIV to analyze sBET-BAF involvement in latency establishment, by using CRISPR/Cas9 to test dynamics of sBET-BAF recruitment to targeted DNA breaks, and by using paired-end sequencing to characterize the response of endogenous retroviruses to sBET-BAF inactivation. 2) To characterize composition and recruitment of sBET-containing complexes. The working hypothesis is that sBET interacts with multiple chromatin-remodeling complexes to silence incoming retroviruses and is recruited to the HIV LTR via zinc-finger proteins. Our specific focus is the NuRD nucleosome-remodeling and deacetylase complex and ZNF592 because of known interactions with sBET and ZMYND8. We will test the hypothesis in comprehensive mutagenesis, co-immunoprecipitation and chromatin immunoprecipitation experiments combined with knockdown of select factors. 3) To determine how RPRD1 proteins regulate HIV transcription. The working hypothesis is that RPRD1 proteins read K7ac marks enriched at the latent HIV promoter and prevent successful elongation of the paused RNA polymerase II. This hypothesis will be tested in detailed chromatin immunoprecipitations of CTD modifications at the HIV promoter and with conditional CRISPRi for RPRD1A/B proteins. As preliminary results implicate RPRD1 proteins in deacetylase recruitment, we will identify and functionally characterize this deacetylase (6). We expect the proposed work to reveal fundamental new biology of HIV latency that may inform future drug development.

IC Name
NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
  • Activity
    R37
  • Administering IC
    AI
  • Application Type
    3
  • Direct Cost Amount
    68189
  • Indirect Cost Amount
    60688
  • Total Cost
    128877
  • Sub Project Total Cost
  • ARRA Funded
    False
  • CFDA Code
    855
  • Ed Inst. Type
  • Funding ICs
    NIAID:128877\
  • Funding Mechanism
    Non-SBIR/STTR RPGs
  • Study Section
    HVCD
  • Study Section Name
    HIV Molecular Virology, Cell Biology, and Drug Development Study Section
  • Organization Name
    J. DAVID GLADSTONE INSTITUTES
  • Organization Department
  • Organization DUNS
    099992430
  • Organization City
    SAN FRANCISCO
  • Organization State
    CA
  • Organization Country
    UNITED STATES
  • Organization Zip Code
    941582261
  • Organization District
    UNITED STATES