BIOLOGY 2C03 Lecture Notes - Lecture 3: Ctcf, Meiosis, Cpg Site
27 Nov 2015
School
Department
Course
Professor
Document Summary
Different genes have different modification = different levels of gene expression: methylation: can activate or repress gene transcription, depending on which amino acids in the histone tail are modified, histone methyltransferases (hmt) adds the methyl groups with histone demethylases (hdmt, acetylation: stimulates gene transcription, histone acetyltransferases (hat) add acetyl groups, acetylation will neutralize the positive charge of the histone so that it relaxes the nucleosomes hold on the dna transcription. Remodel nucleosome to open or close promoter + other regulating sequences: open promoter: have a poly a/t tract in their nucleosome depleted region which allows attracts transcription factors transcribe, closer promoter: require their nucleosome to be removed from the area so that gtf can bind to, open chromatin dna with nucleosomes is relaxed, so regulating proteins can interact with regulatory squences, closed chromatin regulatory sequences and proteins cannot bind = no transcription.
