BIO E105 Lecture Notes - Lecture 12: Chromatin Remodeling, Chromatin, Intron
Document Summary
Some regulatory sequences are far from the promoter: regulatory elements that are far from the promoter are termed enhancers, all eukaryotes have enhancers. Enhancers and silencers: enhancers function using positive control when regulatory proteins bind to enhancers, transcription begins, silencers are similar to enhancers but they function in negative control they repress rather than activate gene expression. What role do regulatory proteins play: different cell types express different genes because they have different histone modifications and contain different regulatory proteins. Differential gene expression is a result of the production or activation of specific regulatory proteins. Although they are required for transcription, they do not regulate gene expression. Step 1: regulatory transcription factors bind to dna and recruit the chromatin-remodeling complexes, or hats. Step 2: chromatin remodeling results in loosening of the chromatin structure, exposing the promoter region. Step 3: additional regulatory transcription factors bind enhancers and promoter-proximal elements; they also interact with basal transcription factors that bind the promoter.
