BIOL 483 Lecture Notes - Lecture 70: Quadruplex Videotape, Litre, Demethylation
Document Summary
Pre = polycomb response elements, sequenece specific dna seq to which proteins bind to recruit prc1/2. No prc2 core complex proteins have inherent dna binding specificity, but are associated with subunits that have domains that recognise different dna sequences. Drosophila have pre to bind many different tfs (eg. pho proteins) and can recruit. Prc to silent target gene through this interaction with tfs. Pres have many binding sites for certain tfs in drosophila. > pres are characterised by large clusters of different elements. In mammals, polycomb recruitment doesn"t happen vai pre, but rather unmethylated promoter cpg islands - ga rich or gcn tandem repeats. > unmethylated promoter cpg islands = areas in promoter where you hav eexpected genome levels of cpg density that hasn"t been lost overtime during polycomb recruitment. > diff protein motifs bind to unmethylated cpg (eg. cxxc, k2m2a - lysine methylase that demethylates h3k36me3 activating mark)
