BIOL408, Unit 3- transcription factors

upstream

towards 5' end of RNA

downstream

towards 3' end of RNA

promotor region

where RNA pols and general TFs bind

TATA box

sequence in eukaryotes for promotor region

general transcription factors

involved in almost all genes, help assemble and recruit RNA pol

specific transcription factors

regulate downstream pathways, can turn on or off genes

enhancers

DNA regions that turn on expression when bound to activators

suppressors

DNA regions that turn off expression when bound to repressors

activators and suppressors are…

transcription factors that contain activation or repression domains

enhancers and suppressors are…

DNA regions

what terms are used to describe proximity to the promotor region

distal and proximal

what two domains are needed in TF binding

DNA binding domain and activation/repression domain

DNA binding domain

determines location of binding on the strand and for what gene

activation/repression domain

determines whether it activates or represses transcription

where do transcription factors interact with DNA?

on the grooves of the helix

monomer binding domains

helix-turn-helix and zinc-finger

dimer binding domains

leucine zipper and helix-loop-helix

mediators

protein complexes that direct the assembly of RNA pol and general TFs

what proteins recruit mediators to bind?

activators

what makes up the structure of chromatin?

histones and nucleosomes

histones

positively charges protein complexes

nucleosome

group of histones wrapped in DNA

what modifications increase transcription?

histone deacetylases and DNA methyltransferases

what modifications decrease transcription?

histone acetyltransferase, DNA demethylases

histone acetylation

addition of acetyl groups that loosens chromatin

DNA methylation

adds methyl groups to DNA to keep it tightly bound

histone methylation

addition of methyl groups to histones, can increase or decrease transcription

chromatin remodeling complexes

physically wrap or unwrap DNA from histones

how can repressors interfere with activators?

by binding to the activator binding site, binding to the activator itself, or binding to the target proteins of the activator

what are 3 common transcription factors?

CREB, Myc and c-FOS

CREB

cAMP response binding element, binds to leucine zipper

Myc and c-FOS are….

families of TFs that serve as proto-oncogenes

Myc

binds to helix-loop-helix and leucine zippers, located downstream of RTKs and MAPK

c-FOS

binds to leucine zippers, is an immediate early gene