GIGUERE - LECTURE 7 Flashcards
Control of Gene Expression at a Distance
what do enhancers do
how is the enhancer bridged to the promoter
what does cohesin do
- four subunit complex
- entraps DNA fibers with ring shape structure
- processes that involve: DNA looping, chromosome segregation and DNA repair
- contributes to the topological organization of the genome, along with CTCF (CCCTC binding factor)
- these two largely co-localise
- loops stabilised by cohesin facilitate enhancer promoter interactions, regulate expression of genes by allowing or preventing specific chromatin contacts
what are super enhancers according to CHIP-seq data analysis
what is the difference between enhancers and super enhancers
where are super enhancers usually found
near genes that have cell specific functions
super enhancers and differentiation
super enhancers and cancer cells
what is a locus control region (LCR)
how were the location and function of the LCR discovered
how do LCRs function
how do eRNAs influence chromatin remodelling
what enhancer RNAs (eRNAs) do?
what are insulators
- type of regulatory element
- block the ability of an enhancer to activate a gene when located between them
- bound by the TF CTCF
- enhancer bound TFs are constrained so that they interact only with genes within the CTCF-CTCF loops
- short segments of genomic DNA
what are the two ways in which insulators can act
- can act as either barrier elements: maintain the border between active and repressive chromatin
- or act as enhancer blockers: delimit the influence of an enhancer in an orientation dependent manner
- insulator can be both at the same time
what happens if you remove a CTCF binding site
insulators and HoxA and HoxC
insulators and cancer cells
insulators in erythroid cells
insulators in brain cells
what are TADs
TADs similarity to insulators
what are levels of genome folding
diagram of genomic distribution of TADs, CTCF and cohesin in relation to genes and active transcription
recap of this lecture
