Chapter 9: Regulation of Transcription Flashcards
key to providing the cell with the correct amount of gene product at the correct time
transcriptional regulation
transcriptional regulation underlies () and employs a wide range of mechanisms
cell differentiation and development
one level of transcriptional regulation is (1), but most regulation comes from (2)
- promoter strength
- targeted gene regulation
targeted gene regulation can happen at (3)
- transcription initiation (most prevalent)
- elongation or termination
- regulation from transcribed RNA itself
regulatory (1) regulate transcription by binding to regulatory (2)
- proteins
- sequences
control relative amount of transcription from promoter
regulatory proteins
2 types of regulatory proteins
- repressors - decrease transcription level
- activators - increase transcription level
specific DNA regions to which regulatory proteins bind
regulatory sequences
in bacteria, sequences recognized by regulatory proteins are called ()
operator sites
bacterial operator sites are typically ()
close to or overlap promoter
if operators or (and common for enhancers) are distal to the gene, DNA must loop around for the regulatory protein to interact with the polymerase, sometimes aided by ()
architectural DNA binding proteins
eukaryotic analogs to bacterial operator sites; usual distal (1000s of bps away) from genes
enhancers
to increase the sophistication and subtlety of regulation, eukaryotic regulatory sequences frequently bind ()
several regulatory proteins
found in more complex eukaryotes; have a combination of enhancer and insulator elements
locus control regions (LCRs)
blocks unwanted interaction between enhancers and certain genes
insulators
role of LCRs in the expression of beta-globin genes
LCRs make sure that only fetal Hb is expressed while in the womb, and only adult Hb is expressed outside of the womb
each regulatory protein has a () that recognizes a specific sequence
DNA binding domain
regulatory proteins are often (), allowing them to have additional domains that give them additional functions
modular
transcription level changes in response to (1); this can be done by changing the (2) of the regulatory proteins
- changing conditions
- activity
small molecules that can bind directly to regulatory proteins and change their conformation upon binding
allosteric effectors
() can also change how regulatory proteins interact
phosphorylation or other covalent modifications
covalent modification, along with other factors such as () serve to fine-tune regulation of gene expression
regulator abundance and localization
() chromatin tends to be actively transcribed
hyperacetylated
hypoacetylated chromatin tends to have () levels of transcription
low