Eukaryotic transcription factors continuted 0.0 / 5 ? BiologyGeneticsUniversityNone Created by: Annabel ForsdykeCreated on: 27-04-15 11:30 Describe the leucine zipper Leu is every 7th amino acid, which is every second turn on the same side of the a helix. two interact and dimerise 1 of 13 Examples of leucine zippers CREB (cAMP responsive element, BDNF, VGF), C/EBP - liver 2 of 13 How does the leucine zipper interact with DNA? Doesn't bind directly, they have a basic region that binds DNA 3 of 13 Describe helix-loop-helix. Short a helix connect by a loop to a longer a helix. Often each helix has a basic dna binding domain. Dimerises 4 of 13 Examples of helix-loop-helix factors bHLH factors are involved in muscle development- MyoD acting on fibroblasts to form muscle cells., Neurogenin in neurogenesis. 5 of 13 What regulates the binding of bHLH factors? inhibitors that dont have a basic region. --> MyoD/ID 6 of 13 How can transcription factors modify chromatin HAT or HDAC activity 7 of 13 Example of a tf that has histone acetylase activity CBP that regulates genes in response to cAMP. 8 of 13 An example of a tf that has histone deacetylase activity thyroid hormone receptor co-repressor recruits a histone deaceylase 9 of 13 What else does CBP do? Help recruit RNA Pol II and act as a histone acetyl transferase 10 of 13 How to target sites bind their condensed chromatin/ Pioneer transcription factors, eg GATA4, FoxA1 11 of 13 Ways TFs are regulated Tissue specific synthesis, regulation of splicing to generate different protein isoforms. , 3. Covalent modification, 4, release fromc ytoplasm, 12 of 13 Example of alternative splicing in regulating TFs Thyroid hormone receptor c-erbAa. C-erbAa-2 produced by alternative splicing and acts as a competative inhibitor of c-erbAa-1 13 of 13
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