Control of Gene Expression

1. Overview
   1. Cell types
      1. housekeeping proteins
   2. External signals
   3. Control steps
   4. Constitutive expression
2. Transcriptional Switches
   1. Background
      1. regulatory DNA sequences
      2. transcription regulators
         1. DNA-binding motifs
         2. dimerization
   2. Repression
      1. Tryptophan operon
         1. operator
         2. tryptophan repressor
   3. Activators
   4. Lac operon
      1. genes & enzymes
         1. b-galactosidase - lacZ
         2. galactoside permease - lac Y
         3. galactoside acetyltransferase - lacA
      2. negative control
         1. lac repressor
            1. allolactose
         2. leaky
      3. positive control
         1. cyclic-AMP
         2. catabolite activator protein
            1. activator-binding site
   5. Sigma factor switches
      1. heat shock proteins
   6. Eukaryotic regulators
      1. enhancers
      1. loop
      2. mediator
      3. euk. repressors
3. Cell type control
   1. 1 gene - many regulators
      1. combinatorial control
   2. 1 regulator - many genes
   3. Cell types
      1. ex. MyoD
   4. Daughter cell transmission
      1. epigenetic inheritance
      2. positive feedback loop
      3. chromatin structure
         1. heterochromatin
         2. euchromatin
      4. DNA methylation
         1. methyltransferasePost-transcriptional Controls
   5. Alternate splicing
   6. Riboswitches
   7. Untranslated regions of mRNA
      1. 5'
      2. 3'