Stimulation of DNA Transcription by the Replication Factor from the Adenovirus Genome in a Chromatin-like Structure

Ken Matsumoto,Mitsuru Okuwaki,Hiroyuki Kawase,Hiroshi Handa,Fumio Hanaoka,Kyosuke Nagata

doi:10.1074/jbc.270.16.9645

Abstract

Adenovirus (Ad) genome DNA is complexed with viral core proteins in the virus particle and in host cells during the early stages of infection. This DNA protein complex, called Ad core, is thought to be the template for transcription and DNA replication in infected cells. The Ad core functioned as template for DNA replication in the cell-free system consisting of viral replication proteins, uninfected HeLa nuclear extracts, and a novel factor, template activating factor-I (TAF-I) that we have isolated from uninfected HeLa cytoplasmic fractions. The Ad core did not function as an efficient template in the cell-free transcription system with nuclear extracts of uninfected HeLa cells. The addition of TAF-I resulted in the stimulation of transcription from E1A and ML promoters on the Ad core. TAF-I was required, at least, for the formation of preinitiation complexes. These observations suggest that, in addition to factors essential for transcription on naked DNA template, the factor such as TAF-I needed for replication of the Ad core is also required for transcription from the Ad genome in a chromatin-like structure.

Highlights

Science, and Culture of Japan and by RIKEN
It is reported that the Ad genome DNA is associated with protein VII in the nuclei of infected cells [5], suggesting that the Ad core is the bona fide template for replication and transcription in infected cells
Russell and co-workers revealed that the Ad core can act as template for the initiation of Ad DNA replication in a cell-free system, the elongation of DNA replication is quite limited to only to 0.1 the length of the genome [6, 7]

Summary

THE JOURNAL OF BIOLOarCAL CHEMISTRY

Vol 270, No 16, Issue of April 21, pp. 9645-9650, 1995 Printed in U.S.A. Stimulation of DNA Transcription by the Replication Factor from the Adenovirus Genome in a Chromatin-like Structure*. Adenovirus (Ad) genome DNA is complexed with viral core proteins in the virus particle and in host cells during the early stages of infection. TAF-I was required, at least, for the formation of preinitiation complexes These observations suggest that, in addition to factors essential for transcription on naked DNA template, the factor such as TAF-I needed for replication of the Ad core is required for transcription from the Ad genome in a chromatin-like structure. In the course of experiments to test the possibility that the Ad core is the functional template for early transcription and DNA replication in cell-free systems, we found that a novel host factor, template activating factor I (TAF-l), greatly stimulates the elongation of DNA replication using the Ad core as template in the cell-free system consisting of viral replication proteins and uninfected HeLa nuclear extracts [8]. This system is promising for the analysis of the molecular mechanism for activation of transcription of the genes in the Ad core, as one of models for the activation of repressed genes

MATERIALS AND METHODS

Replication Factor Stimulates Transcription

RESULTS

Stop I

DIS C US SI ON

REFERE NCES