Long range control of gen exp

jambomber's version from 2015-05-10 10:27

Section 1

Question Answer
What factors control transcription?Interplay b/w TFs histone mods, chromatin conformation modifying enzymes, Movement of enhancers and promoters in and out of higher order chroamtin strucutres
Where do we cataloug relevant information?ENCODE and mod ENCODE overlayed
What do regulatory elements do?Integrate multiple regulatory signals to determine the spatiotemporal pattern of developmental factors
How extensive can a genes network be?Dozens of enhacers in a Mb rregion surounding
How can we locate promoters?Using CAGE to pinpoint TSS
What is a promoter divisble into>Core and proximal reigons - later of which is where context specific regulatory inputs tend to converhge
What are the 3 functional classe of promoter1 tissue specific II Ordered nucleosomes Cpg Islands etc Housekeping III devo ref PLc repression and CpG extending into gene body.
Where does most of infor controlling diversity in expresion come from 100bo enhancers
Models for enhancers Billboard- indep recruited Ehancesome Cooperative interaction TF collection cooperativity but without defined grammar PAX2 Spa enhancer feautres of main 2 models
What are models for communicationTracking - trans init compelx binds @ enhancer and moves along until encounters a promoter, Fac track- causes looping Linking- via inter protein
Why might an ehnacer asay be wrong?Narrow window, unavailable TFs or radically diff seqeuence context
What are markers of 1) Promoters 2) enhancers1) H3Kme2/3 2) H3.3 or H2Az and H3K27 H3KMe3
What does a poised enhancer look lokeH3K4me1 or H3K27me
How does spatial org influecne transcriptionLaminaass 0.1- 10MB Contiuous plycomb domains 100j
What unexpected factors ref long range interactions?Small RNAs and Mediator!?
What is an example of a ncRNA which influences long range interactions HOT TIP @ 5'HOXA locus Stablilises existing chromatin state- thereby influencing long range int
What do active enhancers do?Transription eRNAs widespread Pol II bidirectiona transcription rec by CBP. Pol I transfer?
What does CHIA pet Map?All the regions which interact w/ a spefic protein
What TFs involved in LCR @ B GLobin locusEKLF and GAT1

Section 2

Question Answer
What can insulators be described to do Orchestrate topo arrangement of higher order strcutres
How many CTCF bs's? how many occupied?55,000 only 14,000 oc
Name some Drosophila insulator binding proteinsBEAF @ promoters SU(hW) @ intergenic regions TFIIC?
What supports role of CTCF in loopingFlag tagging + GST pulldowns
How does it relate to Cohesin?Colocalises