Kenichi Imai

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Elucidating the mechanism of human immunodeficiency virus, type 1 (HIV-1) provirus transcriptional silencing in latently infected cells is crucial for understanding the pathophysiological process of HIV-1 infection. It is well established that hypoacetylation of histone proteins by histone deacetylases is involved in the maintenance of HIV-1 latency by(More)
Elucidation of the mechanism of transcriptional silencing of human immunodeficiency virus type 1 (HIV-1) provirus in latently infected cells is crucial to understand the pathophysiology of HIV-1 infection and to develop novel therapies. Here we demonstrate that AP-4 is responsible for the transcriptional repression of HIV-1. We found that AP-4 site within(More)
Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that usually results in latent infection of B cells. The EBV BZLF1 gene product ZEBRA is a master regulator of the transition from latency to the lytic replication cycle. In the latent state, hypoacetylation of histone proteins in the BZLF1 promoter by histone deacetylases (HDACs) is primarily(More)
Latently infected cells harbor the HIV-1 proviral DNA genome primarily integrated into heterochromatin, allowing the persistence of transcriptionally silent proviruses. Hypoacetylation of histone proteins by histone deacetylases (HDAC) is involved in the maintenance of HIV-1 latency by repressing viral transcription. In addition, periodontal diseases,(More)
We have identified human 17beta-hydroxysteroid dehydrogenase type 7 (17beta-HSD 7). The novel human cDNA encodes a 37 kDa protein that shows 78 and 74% amino acid identity with rat and mouse 17beta-HSD 7, respectively. These enzymes are responsible for estradiol production in the corpus luteum during pregnancy, but are also present in placenta and several(More)
To identify the cellular gene target for Tat, we performed gene expression profile analysis and found that Tat up-regulates the expression of the OGG1 (8-oxoguanine-DNA glycosylase-1) gene, which encodes an enzyme responsible for repairing the oxidatively damaged guanosine, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG). We observed that Tat induced OGG1(More)
The p53 binding protein 2 (53BP2) has been identified as the interacting protein to p53, Bcl-2, and p65 subunit of nuclear factor kappaB (NF-kappaB). The TP53BP2 gene encodes two splicing variants, 53BP2S and 53BP2L, previously known as apoptosis stimulating protein 2 of p53 (ASPP2). We found that these 53BP2 proteins are located predominantly in the(More)
The Ets transcription factors of the PEA3 group--E1AF/PEA3, ETV1/ER81 and ERM--are almost identical in the ETS DNA-binding and the transcriptional acidic domains. To accelerate our understanding of the molecular basis of putative diseases linked to ETV1 such as Ewing's sarcoma we characterized the human ETV1 and the mouse ER81 genes. We showed that these(More)
Latently infected cells harbor human immunodeficiency virus type 1 (HIV-1) proviral DNA copies integrated in heterochromatin, allowing persistence of transcriptionally silent proviruses. It is widely accepted that hypoacetylation of histone proteins by histone deacetylases (HDACs) is involved in maintaining the HIV-1 latency by repressing viral(More)
The resurgence in mycobacterial infection worldwide has led to renewed attention to the pathogenesis of Mycobacterium species. Although interferon-gamma (IFN-gamma) is a principal mediator of macrophage activation, macrophages infected with Mycobacterium are poor in response at the cytokine. However, the molecular mechanisms underlying mycobacterial(More)