BIO 346 Lecture Notes - Lecture 3: Ctcf, Nucleosome, Restriction Enzyme
Document Summary
Dna methylation - not causal role (driver/passenger?) Suppresses gene regulation - regulatory sequences (enhancers, promoters, etc. ) but not for coding sequences. Associated with the methylation - may not be the cause of it. Methylated in regulatory sequences: accounting and drivers. Causal - can recruit repressor transcription factors. Methylate dna at position in the genome where there are nucleosomes and have tss (transcription start sites) shut down transcription. Accounting - bind dna & change the methylation status. Changes in nucleosome position that reflect the gain or loss of transcription (perceived changes in methylation status) Nucleosome may move into an inactive position before methylation happens. Methylation - can make sure the site stays off. Tf binding can cause changes in methylation, enzymes used to modify histone tails, nucleosome positioning, induce pluripotent stem cells. Pluripotent stem cells - express 3 tfs cascade of chromatin. Chromatin loops: ctcf, cohesin, mediator & tads.
