CCCTC-binding factor recruitment to the early region of the human papillomavirus 18 genome regulates viral oncogene expression.
Bottom Line: Loss of CTCF binding results in a reduction of a specific alternatively spliced transcript expressed from the early gene region concomitant with an increase in the abundance of unspliced early transcripts.In this study, we show that the essential host cell protein CTCF, which functions in genome-wide chromatin organization and gene regulation, is recruited to the HPV genome and plays an essential role in the regulation of early viral gene expression and transcript processing.These data highlight a novel virus-host interaction important for HPV pathogenicity.
Affiliation: University of St. Andrews, School of Medicine, St. Andrews, Fife, United Kingdom.Show MeSH
Related in: MedlinePlus
Mentions: To confirm our in silico analysis, CTCF binding was assessed in vitro by EMSA. Approximately 200-bp DNA fragments containing the predicted binding motifs were incubated with CTCF protein (Fig. 1A), and complexes were separated by electrophoresis (Fig. 1B). A region of the c-Myc promoter, previously shown to bind CTCF (38), and a fragment of the BPV1 genome not predicted to bind CTCF were included as controls. Fragments also were incubated with wheat germ extract alone and in vitro-translated luciferase to control for nonspecific binding of proteins. Fragments were tested a minimum of three times, and the relative strength of binding compared to that of the c-Myc positive-control DNA fragment was estimated (Table 2 and Fig. 2).
Affiliation: University of St. Andrews, School of Medicine, St. Andrews, Fife, United Kingdom.