Dataset Information

IFI44 suppresses HIV-1 LTR promoter activity and facilitates its latency.

ABSTRACT: IFI44 is an interferon-alfa inducible protein, and is associated with infection of several viruses. However, IFI44 elicits minimal antiviral effects on these viruses, and its exact role is still unknown. Here we show that IFI44 inhibits HIV-1 replication in vitro. Through depletion of endogenous IFI44 or overexpression of IFI44 we confirm that IFI44 suppresses HIV-1 LTR promoter activity and affects viral transcription. Furthermore, we find that IFI44 localizes to nuclei and binds to the HIV-1 LTR promoter in HIV-1 infected cells. Removing suppression of HIV-1 transcription benefits reactivation of HIV-1 proviruses for purging latent reservoirs. We demonstrate that depletion of endogenous IFI44 in J-LAT cells induces reactivation of latent HIV-1. Based on these results, we propose a model in which IFI44 is recruited to the HIV-1 LTR, which may suppress viral transcription and prevent reactivation of latent HIV-1. Our study suggests a previously unrecognized anti-HIV phenomenon for interferon-stimulated proteins.

SUBMITTER: Power D

PROVIDER: S-EPMC4437885 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

IFI44 suppresses HIV-1 LTR promoter activity and facilitates its latency.

Power Derek D Santoso Netty N Dieringer Michael M Yu Jack J Huang Huachao H Simpson Sydney S Seth Ishir I Miao Hongyu H Zhu Jian J

Virology 20150314

IFI44 is an interferon-alfa inducible protein, and is associated with infection of several viruses. However, IFI44 elicits minimal antiviral effects on these viruses, and its exact role is still unknown. Here we show that IFI44 inhibits HIV-1 replication in vitro. Through depletion of endogenous IFI44 or overexpression of IFI44 we confirm that IFI44 suppresses HIV-1 LTR promoter activity and affects viral transcription. Furthermore, we find that IFI44 localizes to nuclei and binds to the HIV-1 L ...[more]

PMID: 25776761

Similar Datasets

Project description:Persistence of a reservoir of latently infected memory T cells provides a barrier to HIV eradication in treated patients. Several reports have implicated the involvement of SWI/SNF chromatin remodeling complexes in restricting early steps in HIV infection, in coupling the processes of integration and remodeling, and in promoter/LTR transcription activation and repression. However, the mechanism behind the seemingly contradictory involvement of SWI/SNF in the HIV life cycle remains unclear. Here we addressed the role of SWI/SNF in regulation of the latent HIV LTR before and after transcriptional activation. We determined the predicted nucleosome affinity of the LTR sequence and found a striking reverse correlation when compared to the strictly positioned in vivo LTR nucleosomal structure; sequences encompassing the DNase hypersensitive regions displayed the highest nucleosome affinity, while the strictly positioned nucleosomes displayed lower affinity for nucleosome formation. To examine the mechanism behind this reverse correlation, we used a combinatorial approach to determine DNA accessibility, histone occupancy, and the unique recruitment and requirement of BAF and PBAF, two functionally distinct subclasses of SWI/SNF at the LTR of HIV-infected cells before and after activation. We find that establishment and maintenance of HIV latency requires BAF, which removes a preferred nucleosome from DHS1 to position the repressive nucleosome-1 over energetically sub-optimal sequences. Depletion of BAF resulted in de-repression of HIV latency concomitant with a dramatic alteration in the LTR nucleosome profile as determined by high resolution MNase nucleosomal mapping. Upon activation, BAF was lost from the HIV promoter, while PBAF was selectively recruited by acetylated Tat to facilitate LTR transcription. Thus BAF and PBAF, recruited during different stages of the HIV life cycle, display opposing function on the HIV promoter. Our data point to the ATP-dependent BRG1 component of BAF as a putative therapeutic target to deplete the latent reservoir in patients.

Dataset Information

IFI44 suppresses HIV-1 LTR promoter activity and facilitates its latency.

Publications

IFI44 suppresses HIV-1 LTR promoter activity and facilitates its latency.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets