Eukaryotic Gene Regulation How are genes turned on amp off in eukaryotes How do cells with the same genes differentiate to perform completely different specialized functions Evolution of gene regulation ID: 474880
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Slide1
Eukaryote Regulation and Gene ExpressionSlide2
Eukaryotic Gene Regulation
How are genes turned on & off
in eukaryotes?
How do cells with the same genes differentiate to perform completely different, specialized functions?Slide3
Evolution of gene regulationSlide4
Evolution of Eukaryotic
regulationSlide5
Points of controlSlide6
Cellular DifferentiationSlide7
DNA packingSlide8
DNA
M
ethylationSlide9
Histone
acetylationSlide10
2. Transcription initiation
Control regions on DNA
promoter
nearby
control sequence on DNA
binding of RNA polymerase &
transcription factors
“base” rate of transcription
enhancer
distant
control
sequences on DNA
binding of activator
proteins
“enhanced” rate (high level)
of transcriptionSlide11
Transcription
FactorsSlide12
3. Post-transcriptional control
Alternative RNA splicing
variable processing of
exons creates a family of proteinsSlide13
4. Regulation of mRNA degradation
Life span of mRNA determines amount of protein synthesis
mRNA can last from hours to weeksSlide14
5. Control of translation
Block initiation of translation stage
regulatory proteins attach to 5' end of mRNA
prevent attachment of ribosomal subunits & initiator tRNAblock translation of mRNA to proteinSlide15
6-7. Protein processing & degradation
Protein processing
folding, cleaving, adding sugar groups, targeting for transport
Protein degradation
ubiquitin
tagging
proteasome
degradationSlide16
Ubiquitin
Death tag”
mark unwanted proteins with a label
76 amino acid polypeptide, ubiquitinlabeled proteins are broken down rapidly in "waste disposers"
proteasomesSlide17
Proteasome
Protein-degrading “machine”
cell’s waste disposer
breaks down any proteins into 7-9 amino acid fragments
cellular recycling