| dc.description.abstract | Regulation of gene transcription occurs in a variety of ways, including the direct interaction of proteins with DNA, and the indirect effect of hormones. In addition to daily cell functions, gene regulatory mechanisms have been implicated in the development and proliferation of some diseases such as some forms of cancer. Understanding of these regulatory mechanisms has been approached by extensive biochemical studies of a few basic biological systems. The mouse mammary tumor virus (MMTV), a retrovirus that is present in many mouse cell types but specifically attacks the mammary cells, has been extensively studied. for its hormonal regulation of transcription. Retroviruses are increasingly under study because of their unique system of carrying ssRNA which, upon infection of the host cell, is transcribed to dsDNA by the enzyme reverse transcriptase. The host cell genes produce the trans-acting factors which, upon integration of the proviral DNA into the host genome, modulate viral gene transcription. Understanding of transcriptional regulation of the proviral DNA thus gives valuable information which can be broadly applied to many other gene systems. Any cis-acting elements are restricted to the proviral DNA region and are thus easier to locate if not already known. MMTV transcription is positively regulated by hormones and contains several negative regulatory elements (NREs). These two control mechanisms along with the retrovirus characteristics, make it an ideal model system for the study of gene regulation. Similarities between MMTV regulation and regulation of genes in higher eukaryotes have already been found. However, before the overall transcription process can be fully understood, an understanding of transcription mechanisms in the absence of regulation must be elucidated. The promoter elements necessary for basal transcription must be clearly identified for an effective study to be done. This research project focuses on determining the presence of one such promoter element. | en |
