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more regulating gene expression. Gene Expression is controlled at all of these steps: DNA packaging Transcription RNA processing and transport RNA degradation Translation Post-translational. Fig 15.1. Fig 16.1. Gene Expression is controlled at all of these steps: DNA packaging - PowerPoint PPT Presentation
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more regulating gene expression
Fig 16.1
Gene Expression is controlled at all of these steps:•DNA packaging•Transcription•RNA processing and transport•RNA degradation•Translation•Post-translational
Fig 15.1
Fig 16.1
Gene Expression is controlled at all of these steps:•DNA packaging•Transcription•RNA processing and transport•RNA degradation•Translation•Post-translational
Fig 15.1
Fig 23.25
Alternate Splicing in Drosophila Sex Determination
Alternate splicing leads to sex determination in fruit flies
Fig 23.25
Molecular Biology of the Cell 4th ed. Alberts et al. Fig 6.40http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.TOC&depth=2
mRNA transport is an important regulatory step
Molecular Biology of the Cell 4th ed. Alberts et al. Fig 7.52http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.TOC&depth=2
mRNA can be localized to a specific parts of a cell (from Drosophila embryo)
Molecular Biology of the Cell 4th ed. Alberts et al. Fig 7.98
At least 3 mechanisms are involved:
Directed transport via cytoskeleton
Random diffusion and trapping
Degradation and local protection
A processed mRNA ready for translation
Protects from degradation/ recognition for ribosome
Protects from degradation/ transport to cytoplasm
5’ untranslatedregion
3’ untranslatedregion
Molecular Biology of the Cell 4th ed. Alberts et al. Fig 7.99http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mboc4.TOC&depth=2
mRNA with 3’ UTR properly localized
mRNA without 3’ UTR improperly localized
Fig 16.1
Gene Expression is controlled at all of these steps:•DNA packaging•Transcription•RNA processing and transport•RNA degradation•Translation•Post-translational
Fig 15.1
Fig 16.1
Gene Expression is controlled at all of these steps:•DNA packaging•Transcription•RNA processing and transport•RNA degradation•Translation•Post-translational
Fig 15.1
Fig 15.25
Regulation of iron assimilation in mammals:Regulating of Translation
Fig 15.26Ferritin is regulated at translation
C. elegans is commonly used to study development
C. elegans development
C. elegans mutants with cells that do not develop properly.
C. elegans mutants with cells that do not develop properly.
The product of these genes was found to be RNA?
Cell vol. 116,281-297 2004
MicroRNAs (miRNA) are ~22nt RNAs that play important regulatory roles
How do microRNAs control gene expression?
miRNA expressed
miRNA processed to ~22nt RNA
Mature miRNA
Fig 15.23 and
A processed mRNA ready for translation:microRNAs inhibit translation by binding to the 3’ end of mRNA
microRNA bind to 3’-UTR
5’-UTR3’-UTR
miRNA expressed
miRNA processed to ~22nt RNA
Mature miRNA
the 3’ end with attached microRNA interacts with the 5’ end, blocking translation
Fig 15.23 and
miRNAs can lead to methylation of DNA that
leads to inhibition of transcription
microRNAs primarily target gene products that function during development
Tbl 1
PNAS vol. 101 #1 pg 360-365, 2004
tissue specific expression of mouse microRNA
Fig 16.1
Gene Expression is controlled at all of these steps:•DNA packaging•Transcription•RNA processing and transport•RNA degradation•Translation•Post-translational
Phosphorylation and dephosphorylation of proteins can change activity
Ubiquitinization targets proteins for degradation
Some proteins function in the cytoplasm; others need to be transported to various organelles.
How can proteins be delivered to their appropriate destinations?
Fig 13.23
Proteins are directed to their destinations via signals in the amino acid sequence
Protein Destinations: secretion or membrane
• Signal sequences target proteins for secretion
Translation of secreted proteins
Translation of membrane bound proteins
Translation of secreted or membrane bound proteins
This step determines secretion or membrane bound.
Protein Destinations: nucleus Signal anywhere in protein, Translation in cytoplasm,Signal not removed
Protein Destinations: mitochondria or chloroplast
Signal translated first, Translation in cytoplasm, Signal removed
Protein Destinations: signals in protein determine destination
Tbl 13.8
Next: Development- differentiating cells to become an organism