Initiation of adenovirus DNA replication is strongly enhanced by two cellular transcription factors, NFI and Oct-1, which bind to the auxiliary origin and tether the viral precursor terminal protein-DNA polymerase (pTP.pol) complex to the core origin. NFI acts through a direct contact with the DNA polymerase, but the mode of action of Oct 1 is unknown. Employing glutathione S-transferase-POU pull-down assays and protein affinity chromatography, we have established that the POU domain contacts pTP rather than pol. The POU homeodomain is responsible for this interaction. The protein-protein contacts lead to increased binding of pTP-pol to the core origin, which is caused by a reduced off-rate. The enhanced formation of a pTP.pol.POU complex on the origin correlates with stimulation of replication. Using an immobilized replication system, we have studied the kinetics of dissociation of the Oct-1 POU domain during replication. In contrast to NFI, which dissociates very early in initiation, Oct-1 dissociates only when the binding site is rendered single-stranded upon translocation of the replication fork. Our data indicate that NFI and Oct-1 enhance initiation synergistically by touching different targets in the preinitiation complex and dissociate independently after initiation.
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http://dx.doi.org/10.1074/jbc.272.6.3398 | DOI Listing |
Kidney Int Rep
August 2024
National Institute of Health and Medical Research (INSERM), UMR 1297, Institute of Cardiovascular and Metabolic Disease, Toulouse, France.
Rev Med Virol
November 2022
Institute of Life Science and Green Development, School of Life Science, Hebei University, Baoding, China.
Herpes simplex virus type 1 (HSV-1) is an important human pathogen with neurotropism. Following lytic infection in mucosal or skin epithelium, life-long latency is established mainly in sensory neurons, which can periodically reactivate by stress, leading to recurrent disease and virus transmission. During the virus's productive infection, the tegument protein VP16, a component of HSV-1 virion, is physically associated with two cellular factors, host cell factor-1 (HCF-1), and POU domain protein Oct-1, to construct the VP16-induced complex, which is essential to stimulate immediate early (IE)-gene transcription as well as initiate the lytic programme.
View Article and Find Full Text PDFBMC Cancer
October 2020
Department of Hematology, Hemotherapy and Cell Therapy, Faculty of Medicine, Sao Paulo University (FM-USP), São Paulo, Brazil.
Background: OCT-1 gene is a member of the POU-homeodomain family of transcriptional regulators of B-lymphocyte differentiation by controlling expression of B-cell specific genes. BCL-2 gene is a potent inhibitor of apoptosis and it is essential during B-cell differentiation into germinal center. These genes may be expressed in diffuse large B-cell lymphoma (DLBCL), but the role of BCL-2 in its prognosis has been contradictory, and OCT-1 has yet to be tested.
View Article and Find Full Text PDFSci China Life Sci
February 2021
Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital; NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides; Key Laboratory of Molecular Cardiovascular Science, Ministry of Education; Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing, 100191, China.
Cardiac fibroblast (CF) differentiation into myofibroblasts is a crucial cause of cardiac fibrosis, which increases in the extracellular matrix (ECM) stiffness. The increased stiffness further promotes CF differentiation and fibrosis. However, the molecular mechanism is still unclear.
View Article and Find Full Text PDFJ Biol Chem
August 2019
Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103; Graduate School of Biomedical Sciences, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Rutgers University, Newark, New Jersey 07103. Electronic address:
Reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV) from latency requires the viral transactivator Rta to contact the host protein Jκ recombination signal-binding protein (RBP-Jκ or CSL). RBP-Jκ normally binds DNA sequence-specifically to determine the transcriptional targets of the Notch-signaling pathway, yet Notch alone cannot reactivate KSHV. We previously showed that Rta stimulates RBP-Jκ DNA binding to the viral genome.
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