© 2014 Pearson Education, Inc. Chapter 19 Opener Transcriptional regulation in eukaryotes

© 2014 Pearson Education, Inc. Figure 19-1 Regulatory elements of bacterial and yeast and human genes

© 2014 Pearson Education, Inc. Figure 19-2 Yeast Gal4 (activator of Gal1)bound to its DNA

© 2014 Pearson Education, Inc. Figure 19-3 Regulatory sequence of Gal1 gene Upstream activating sequence(of gal)

© 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

© 2014 Pearson Education, Inc. Figure 19-6 Zinc finger domain

© 2014 Pearson Education, Inc. Figure 19-7 Leucine zipper domain

© 2014 Pearson Education, Inc. Figure 19-8 Helix loop helix motif

© 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)

© 2014 Pearson Education, Inc. Figure Activation of transcription through direct tethering of mediator to DNA

© 2014 Pearson Education, Inc. Figure Activation of HATs (histone acetyltransferase): nucleosome modifier with bromodomain protein (recognize acetylated nucleosome) with chromomodomain (recognize methylated nucleosome)

© 2014 Pearson Education, Inc. Figure 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)

© 2014 Pearson Education, Inc. Figure Action at a distance : loops and insulators( 차단자 )

© 2014 Pearson Education, Inc. Figure Cooperative binding (a, b) Indirect effect in which binding of one protein helps 2 nd protein to bind (c, d)

© 2014 Pearson Education, Inc. Figure 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

© 2014 Pearson Education, Inc. Figure 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)

© 2014 Pearson Education, Inc. Figure Enhanceosome structure and sequence

© 2014 Pearson Education, Inc. Figure 19-19a

© 2014 Pearson Education, Inc. Figure 19-19b

© 2014 Pearson Education, Inc. Figure 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)

© 2014 Pearson Education, Inc. Figure Transcriptional repressors

© 2014 Pearson Education, Inc. Figure 19-22a

© 2014 Pearson Education, Inc. Figure 19-22b

© 2014 Pearson Education, Inc. Figure 19-22c

© 2014 Pearson Education, Inc. Figure 19-22d

© 2014 Pearson Education, Inc. Figure Repression of Gal1 gene by Mig1 Upstream activating sequence(of gal) Tup1 recruits deacetylase (in nucleosome) Mig 1 (Multicopy Inhibitor of GAL gene expression)

© 2014 Pearson Education, Inc. Two signal transduction pathways from mammalian cells

© 2014 Pearson Education, Inc. Figure 19-24a Signal transduction pathways (of STAT) from mammalian cells Outside cell cytoplasm

© 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)

© 2014 Pearson Education, Inc. Figure 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)

© 2014 Pearson Education, Inc. Figure Silencing at the yeast telomere (Histone discetylase) Sir(Silencing information protein) Repressor/Activator site binding Protein (Rap 1) recruits Sir proteins in nucleosome.

© 2014 Pearson Education, Inc. Figure 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.

© 2014 Pearson Education, Inc. Figure 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

© 2014 Pearson Education, Inc. Figure 19-29a

© 2014 Pearson Education, Inc. Figure 19-29b

© 2014 Pearson Education, Inc. Figure Switching a gene off through DNA methylation and histone modification off but leaky activator

© 2014 Pearson Education, Inc. Figure In mammalian lgf2 (only in maternal) and H19 genes

© 2014 Pearson Education, Inc. Figure Epigenetic control of maintenance of the lysogenic state (inheritance of gene expression patterns, the absence of signal, is called epigenetic regulation)

© 2014 Pearson Education, Inc. Figure 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