Download presentation
Presentation is loading. Please wait.
Published byTobias Woods Modified over 8 years ago
1
© 2014 Pearson Education, Inc. Chapter 19 Opener Transcriptional regulation in eukaryotes
2
© 2014 Pearson Education, Inc. Figure 19-1 Regulatory elements of bacterial and yeast and human genes
3
© 2014 Pearson Education, Inc. Figure 19-2 Yeast Gal4 (activator of Gal1)bound to its DNA
4
© 2014 Pearson Education, Inc. Figure 19-3 Regulatory sequence of Gal1 gene Upstream activating sequence(of gal)
5
© 2014 Pearson Education, Inc. Figure 19-5 Eukaryotic regulators use a range of DNA binding domain, but DNA recognition involves the same principles as found in bacteria DNA recognition by a homeodomain (first found in Drosophila developmental gene) - Helix turn helix motif with more variation in eukaryotes
6
© 2014 Pearson Education, Inc. Figure 19-6 Zinc finger domain
7
© 2014 Pearson Education, Inc. Figure 19-7 Leucine zipper domain
8
© 2014 Pearson Education, Inc. Figure 19-8 Helix loop helix motif
9
© 2014 Pearson Education, Inc. Figure 19-9 Recruitment of protein complexes to genes by eukaryotic activators (usually by more than one which is not shown)
10
© 2014 Pearson Education, Inc. Figure 19-10 Activation of transcription through direct tethering of mediator to DNA
11
© 2014 Pearson Education, Inc. Figure 19-11 Activation of HATs (histone acetyltransferase): nucleosome modifier with bromodomain protein (recognize acetylated nucleosome) with chromomodomain (recognize methylated nucleosome)
12
© 2014 Pearson Education, Inc. Figure 19-12 Pausing and releasing of Pol II (activators recruit additional factors needed for efficient initiation or elongation) P-TEFb (part of super elongation complex, SEC) NELF (negative elongation factor) DPE/PB (pause button site)
13
© 2014 Pearson Education, Inc. Figure 19-14 Action at a distance : loops and insulators( 차단자 )
14
© 2014 Pearson Education, Inc. Figure 19-16 Cooperative binding (a, b) Indirect effect in which binding of one protein helps 2 nd protein to bind (c, d)
15
© 2014 Pearson Education, Inc. Figure 19-17 Control of HO gene: SWI5 binds to its sites in chromatin unaided but SBF(activator) can not. Remodelers and HATs recruited by SWI5 allows SBF bind to its site. Budding related gene in yeast
16
© 2014 Pearson Education, Inc. Figure 19-18 Signal integration: cooperative binding of activators at the human beta-interferon gene by activated by viral infection) Human beta-interferon enhanceosome a family of high mobility group proteins characterized by an AT- hook (HMGA) Interferon regulatory factor (IRF) activating transcription factor (ATF)
17
© 2014 Pearson Education, Inc. Figure 19-19 Enhanceosome structure and sequence
18
© 2014 Pearson Education, Inc. Figure 19-19a
19
© 2014 Pearson Education, Inc. Figure 19-19b
20
© 2014 Pearson Education, Inc. Figure 19-20 Combinatorial control. (a) controlled by four signals (regulatory proteins); (b) three control. Signal 3 controls both genes. (This can be with many more regulators in Drosophila and human)
21
© 2014 Pearson Education, Inc. Figure 19-22 Transcriptional repressors
22
© 2014 Pearson Education, Inc. Figure 19-22a
23
© 2014 Pearson Education, Inc. Figure 19-22b
24
© 2014 Pearson Education, Inc. Figure 19-22c
25
© 2014 Pearson Education, Inc. Figure 19-22d
26
© 2014 Pearson Education, Inc. Figure 19-23 Repression of Gal1 gene by Mig1 Upstream activating sequence(of gal) Tup1 recruits deacetylase (in nucleosome) Mig 1 (Multicopy Inhibitor of GAL gene expression)
27
© 2014 Pearson Education, Inc. Two signal transduction pathways from mammalian cells
28
© 2014 Pearson Education, Inc. Figure 19-24a Signal transduction pathways (of STAT) from mammalian cells Outside cell cytoplasm
29
© 2014 Pearson Education, Inc. Figure 19-24b Signal transduction pathways (of Ras) from mammalian cells (Adapter protein) of transcriptional activators like Jun that regulate many genes like beta-interferon Ras GEF (guanine nucleotide exchange factor)
30
© 2014 Pearson Education, Inc. Figure 19-26 Gene “siliencing” by modification of histones and DNA. Also by DNA methylase common in mammalian cell but not in yeast. In yeast by methyltransferase DAPI staining of heterochromatin (chromatin is densely packed into heterochromatin)
31
© 2014 Pearson Education, Inc. Figure 19-27 Silencing at the yeast telomere (Histone discetylase) Sir(Silencing information protein) Repressor/Activator site binding Protein (Rap 1) recruits Sir proteins in nucleosome.
32
© 2014 Pearson Education, Inc. Figure 19-28 Position effect variegation( 색갈이 다른 것 ) i n Drosophila When gene is mutated, eyes are white so called white gene. When wild type gene is adjacent to heterchromatin, the expression is variegated, with some cells expressing the gene and some not. H1 protein (coded by Su(var)3-9) recognizes methylated histones and condenses chromatin.
33
© 2014 Pearson Education, Inc. Figure 19-29 Repression by polycomb also uses histone methylation Polycomb repressive complex 1 Polycomb Response Elements (PREs) DNA binding subunit (PHO or PHOL - Repressive Complex ) Polycomb protein (PHO) = Protein pleiohomeotic
34
© 2014 Pearson Education, Inc. Figure 19-29a
35
© 2014 Pearson Education, Inc. Figure 19-29b
36
© 2014 Pearson Education, Inc. Figure 19-30 Switching a gene off through DNA methylation and histone modification off but leaky activator
37
© 2014 Pearson Education, Inc. Figure 19-31 In mammalian lgf2 (only in maternal) and H19 genes
38
© 2014 Pearson Education, Inc. Figure 19-32 Epigenetic control of maintenance of the lysogenic state (inheritance of gene expression patterns, the absence of signal, is called epigenetic regulation)
39
© 2014 Pearson Education, Inc. Figure 19-33 Maintenance methyalse modify hemimethylated DNA (only parental DNA). In mammalian cell, DNA methylation may be the primary maker of regions of genome that is silenced. (Epigenetic gene regulation) Being recognized based on the other methylated cytosine
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.