Registration for a live webinar on 'Chronic inflammation, immune cell trafficking and anti-trafficking agents' is now open.See webinar details
The basal transcription machinery for RNA polymerase II
Published on February 4, 2014 42 min
Other Talks in the Series: Epigenetics, Chromatin, Transcription and Cancer
The Myc transcription factor network
- Prof. Robert N. Eisenman
- Fred Hutchinson Cancer Research Center, USA
Role of polycomb proteins in gene transcription, stem cell and human diseases
- Prof. Luciano Di Croce
- Center for Genomic Regulation, Spain
My name's Mark Timmers. I've been interested in the process of gene regulation for a very long time, and in doing so, we've gathered a number of insights. I'm going to share with you what we've learned about the basal transcription by RNA polymerase ii.
But before we go into the details of the basal transcription process itself, it's important to review the elements which are controlling the process of transcription. These are typically, as indicated in orange here, the enhancer sequences which can be located either upstream or downstream or even in the gene, a locus control region which can act over larger distances, and the function of these DNA elements fits into the events that are happening at the start site, indicated by the arrow. And the start site is part of the core promotor sequence, which is surrounding the start site. And it's about only 50 base pairs in total sequence. Although we know that these elements are important from the simple act of looking at the DNA sequences, it's very difficult to find these functional elements.
These DNA elements function by attracting proteins. From the DNA sequence of a number of genes, we can now determine the number of genes which are involved in expression of the genome. For a simple eukaryote like yeast, which has about 6,000 genes, there's about 170 gene-specific transcription factors which bind to upstream sequences like enhancers. There's about 250 or so chromatin remodeling and modifying factors. And if we focus on the basal machinery, there's about 60 to 70 general transcription machinery proteins. In addition to this, yeast has about 20 elongation proteins and there's a number of upstream regulatory factors like kinases, ubiquitin, rare proteins, mRNA splicing proteins, export proteins. I'm not going to talk about those. So the total set is about 60 proteins which are involved in basal machinery.