Cytochrome P450 Gene Regulation

Abstract

Most mechanistic analyses of gene regulation are performed in contexts different from the physiological conditions of the intact cell. For example, transcription factors are often studied according to their ability to modulate the expression of plasmid-based reporter genes rather than endogenous chromosomal genes; DNA regulatory elements are usually analyzed as oligonucleotides in vitro or as components of recombinant plasmids, rather than in their native chromosomal setting. Such studies, though informative, may not faithfully reflect gene regulation in vivo. In addition, many studies ignore the regulatory effects of chromatin structure on gene expression. In studies that do address chromatin structure, reconstituted chromatin is often analyzed in vitro; in such situations, the stoichiometric relationship between DNA and transcription factors may not resemble those found in vivo, and other important regulatory macromolecules may be inactive or missing. Therefore, it is important to develop approaches for studying gene regulation under conditions similar to those that exist in VIVO.