Eukaryotic gene regulation (14.2) Flashcards
Eukaryotic gene regulation occurs at multiple levels. What are 2 stages?
Nucleus
–> chromatin packaging/unpackaging
–> transcription
–> intro processing
Cytoplasm
–> translation
–> RNA stability
–> post-translation modifications
Where does gene expression (transcription) occur
uncondensed regions of DNA
Chromatin remodeling is the result of histone and DNA modifications
Histone tail acetylation tends to relax chromatin, which leads to what kind of expression?
DNA methylation tends to lead to together compaction which leads to what kind of expression?
high expression; low expression
What are writers?
Introduce modifications on DNA and histone tails
What are readers?
recognize these modifications and recruit chromatin remodeling enzymes, or recruit transcription factors
What are erasers?
Erasers remove the modifications introduced by the writers
Negative regulation are the
Repressors (co repressor or inducer molecules)
Positve regulation are the
activators (inducers or inhibitors)
Trans enhancer elements
Upstream activating sequences (UAS)
Insulators
cis (near the promoter) regulatory elements recruit proteins that block the action of enhancer elements
What is Tra?
Protein requireed for female sex development
What is Sxl?
Splicing factor that is required to produce the mRNA that can synthesize the Tra protein
Euk mRNAs contain
1 ORF (sometimes with introns that need to be removed
5’ CAP (added after transcription)
polyA tail (added after transcription by polyA polymerase)
Regulatory information in the 5’ and 3’ UTRs
PolyA binding proteins can
Promote translation
Terminate translation
Trigger mRNA degradation
Two types of gene regulation through RNA switches
Riboswitch and thermoswitch
Riboswitch
A secondary structure in RNA that occur when a ligand binds that results in a change in protein synthesis
What kind of domain is a riboswitch in?
5’ UTR domain
What can riboswitches do?
Block transcription by creating termination sequences
Recruit factors that cleave RNA
Recruit splicing factors to alter intron processing
Block the RBS preventing translation
Thermoswitch
Regulatory segment of an mRNA that forms under certain temperatures
Two types of gene regulation through ncRNAs
RNAinterference (RNAi)
Long ncRNAs (IncRNAs)
