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Control of Gene ExpressionControl of Gene ExpressionControl of Gene ExpressionControl of Gene Expression
©Copyright 1999-2004 by Gene C. Lavers
No part of this presentation may be reproduced by any mechanical, photographic, or electronic process, or in the form of a phonographic recording, nor may it be stored in a retrieval system, transmitted, or otherwise copied for public or private use, without written permission from the publisher.
©Copyright 1999-2004 by Gene C. Lavers
No part of this presentation may be reproduced by any mechanical, photographic, or electronic process, or in the form of a phonographic recording, nor may it be stored in a retrieval system, transmitted, or otherwise copied for public or private use, without written permission from the publisher.
Lecture 53-54Lecture 53-54Baynes & Dominiczak, Baynes & Dominiczak, Chapter 32Chapter 32
Gene C. Lavers, Ph.D.Gene C. Lavers, Ph.D.gcl1@nyu.edugcl1@nyu.edu
Lecture 53-54Lecture 53-54Baynes & Dominiczak, Baynes & Dominiczak, Chapter 32Chapter 32
Gene C. Lavers, Ph.D.Gene C. Lavers, Ph.D.gcl1@nyu.edugcl1@nyu.edu
© 1999-2004 by Gene C. Lavers, Ph.D.
2
5400 nucleotides code for 200,000 daltons in 9 viral proteins5400 nucleotides code for 200,000 daltons in 9 viral proteins 5400 nt / 3 coding ratio = 1600 aa is the coding potential5400 nt / 3 coding ratio = 1600 aa is the coding potential But, 250,000 d of proteins expressed! (50,000/110 = But, 250,000 d of proteins expressed! (50,000/110 = 455 extra455 extra aa) aa) 50,000 d extra protein due to overlapping 50,000 d extra protein due to overlapping DD, , EE genes; also genes; also DD and and JJ genes, genes, which overlap by 1-nucleotidewhich overlap by 1-nucleotide
5400 nucleotides code for 200,000 daltons in 9 viral proteins5400 nucleotides code for 200,000 daltons in 9 viral proteins 5400 nt / 3 coding ratio = 1600 aa is the coding potential5400 nt / 3 coding ratio = 1600 aa is the coding potential But, 250,000 d of proteins expressed! (50,000/110 = But, 250,000 d of proteins expressed! (50,000/110 = 455 extra455 extra aa) aa) 50,000 d extra protein due to overlapping 50,000 d extra protein due to overlapping DD, , EE genes; also genes; also DD and and JJ genes, genes, which overlap by 1-nucleotidewhich overlap by 1-nucleotide
Overlapping Genes Overlapping Genes Genome Genome moleculemolecule phagephage X174X174
Overlapping Genes Overlapping Genes Genome Genome moleculemolecule phagephage X174X174
Circular ChromosomeCircular ChromosomeCircular ChromosomeCircular Chromosome
DDDDEEEE
JJJJ
© 1999-2004 by Gene C. Lavers, Ph.D.
3
Gene Expression Gene Expression ConceptsConceptsBacteriophage Bacteriophage X-174X-174 Gene Expression Gene Expression ConceptsConceptsBacteriophage Bacteriophage X-174X-174
mRNAmRNA E proteinE protein:: val arg val arg trptrp thr thr
pppGUA--//--GGUAAGAAAUCpppGUA--//--GGUAAGAAAUCAUG AUG AGU CAA GUU--//--UGC GUU UAGU CAA GUU--//--UGC GUU UAU GAU GGU ACG CUGU ACG CUGG GAC GAC
D proteinD protein:: ser gln val --//--cys val tyr gly thr ser gln val --//--cys val tyr gly thr leuleu aspasp
-- -- E proteinE protein------Arg lys glu------Arg lys glu | | ser lys gly lys ------ ser lys gly lys ------ J proteinJ protein------------>>
---------------------GCG GAA GGA GUG AUG ---------------------GCG GAA GGA GUG AUG UAUAAA UGUG UCU AAA GGU AAA -----------------------> 5’ UCU AAA GGU AAA -----------------------> 5’
-- D protein --- -- D protein --- ala glu gly val metala glu gly val met | | COOHCOOH
ObservationsObservations D and E use two framings shifted by 1 position (G4 virus has 3 overlapping D and E use two framings shifted by 1 position (G4 virus has 3 overlapping
frames!!)frames!!) D stop UAA overlaps J-protein Start AUG. D stop UAA overlaps J-protein Start AUG. i.ei.e., UA., UAAAUGUG D, E, and J proteins all have different framing from each otherD, E, and J proteins all have different framing from each other Synonym mutation in D protein’sSynonym mutation in D protein’s leu-codon, CUleu-codon, CUGG to to CUCUAA: yields normal D: yields normal D Effect in E protein: trp-codon UEffect in E protein: trp-codon UGGG to UG to UAAG stop codon: yields E as a tripeptideG stop codon: yields E as a tripeptide D, E, and J’s D, E, and J’s fmetfmet removed by protease (a posttranslational modification) removed by protease (a posttranslational modification)
mRNAmRNA E proteinE protein:: val arg val arg trptrp thr thr
pppGUA--//--GGUAAGAAAUCpppGUA--//--GGUAAGAAAUCAUG AUG AGU CAA GUU--//--UGC GUU UAGU CAA GUU--//--UGC GUU UAU GAU GGU ACG CUGU ACG CUGG GAC GAC
D proteinD protein:: ser gln val --//--cys val tyr gly thr ser gln val --//--cys val tyr gly thr leuleu aspasp
-- -- E proteinE protein------Arg lys glu------Arg lys glu | | ser lys gly lys ------ ser lys gly lys ------ J proteinJ protein------------>>
---------------------GCG GAA GGA GUG AUG ---------------------GCG GAA GGA GUG AUG UAUAAA UGUG UCU AAA GGU AAA -----------------------> 5’ UCU AAA GGU AAA -----------------------> 5’
-- D protein --- -- D protein --- ala glu gly val metala glu gly val met | | COOHCOOH
ObservationsObservations D and E use two framings shifted by 1 position (G4 virus has 3 overlapping D and E use two framings shifted by 1 position (G4 virus has 3 overlapping
frames!!)frames!!) D stop UAA overlaps J-protein Start AUG. D stop UAA overlaps J-protein Start AUG. i.ei.e., UA., UAAAUGUG D, E, and J proteins all have different framing from each otherD, E, and J proteins all have different framing from each other Synonym mutation in D protein’sSynonym mutation in D protein’s leu-codon, CUleu-codon, CUGG to to CUCUAA: yields normal D: yields normal D Effect in E protein: trp-codon UEffect in E protein: trp-codon UGGG to UG to UAAG stop codon: yields E as a tripeptideG stop codon: yields E as a tripeptide D, E, and J’s D, E, and J’s fmetfmet removed by protease (a posttranslational modification) removed by protease (a posttranslational modification)
fmet
fmetfmet
fmetfmet
Translating Overlapping GenesTranslating Overlapping GenesTranslating Overlapping GenesTranslating Overlapping Genes
© 1999-2004 by Gene C. Lavers, Ph.D.
4
RegulatorRegulator Gene Structural genesGene Structural genes
||==== ii ==| ==| ==== pp ==|====|== oo ==== |====== |======zz =======|=======|========yy ======||====== aa ======== || | |
| |
i i mRNA mRNA laclac mRNA mRNA
RepressorRepressor -galactosidase -galactosidase permeasepermease transacetylasetransacetylase
Operator with 35 bp and 2-fold symmetryOperator with 35 bp and 2-fold symmetry
-21 -3-21 -3
5’ (-) - - 5’ (-) - - TGTGTG G AATTGTTGTGTG G AATTGT G A G C G G A T A G A G C G G A T A ACAATT T CACACAACAATT T CACACA - - - - - - - - - -
3’ (+) - - 3’ (+) - - ACACACACACAC C C TTAACATTAACA C C TT C C GG C C CC T T AA T T TGTTAATGTTAA A A GTGTGTGTGTGT - - - - - - - - - -
|--- 22 bp protected by Repressor --------||--- 22 bp protected by Repressor --------|
RegulatorRegulator Gene Structural genesGene Structural genes
||==== ii ==| ==| ==== pp ==|====|== oo ==== |====== |======zz =======|=======|========yy ======||====== aa ======== || | |
| |
i i mRNA mRNA laclac mRNA mRNA
RepressorRepressor -galactosidase -galactosidase permeasepermease transacetylasetransacetylase
Operator with 35 bp and 2-fold symmetryOperator with 35 bp and 2-fold symmetry
-21 -3-21 -3
5’ (-) - - 5’ (-) - - TGTGTG G AATTGTTGTGTG G AATTGT G A G C G G A T A G A G C G G A T A ACAATT T CACACAACAATT T CACACA - - - - - - - - - -
3’ (+) - - 3’ (+) - - ACACACACACAC C C TTAACATTAACA C C TT C C GG C C CC T T AA T T TGTTAATGTTAA A A GTGTGTGTGTGT - - - - - - - - - -
|--- 22 bp protected by Repressor --------||--- 22 bp protected by Repressor --------|
Gene Expression Gene Expression Molecular Molecular GeneticsGenetics ProkaryoteProkaryote
Gene Expression Gene Expression Molecular Molecular GeneticsGenetics ProkaryoteProkaryote
Lac OperonLac OperonLac OperonLac Operon
© 1999-2004 by Gene C. Lavers, Ph.D.
5
DNADNA
|- - - - - - -|- - - - - - -promoterpromoter - - - - - - - - - - | - - - - - - - - - - | |------coding-- … |------coding-- … 5’ TC 5’ TC AAATTGTGAGCGGA TAACAATTTAAATTGTGAGCGGA TAACAATTT GA CACAGG AAACAGCT GA CACAGG AAACAGCTATG ACCATGATTATG ACCATGATT----- …----- …
5’ AG5’ AGTTTTAACATTAACACTC GCCT ATCTC GCCT ATTGT TAATGT TAAAA CTGTGT CC TTTG TCGATAC TGGTACTAA CTGTGT CC TTTG TCGATAC TGGTACTAA----- … ----- …
mRNA mRNA purine-rich purine-rich pppAAUUGUGAGCGGAUAACAAUUUGACpppAAUUGUGAGCGGAUAACAAUUUGACACAGGAAACAGACAGGAAACAGCUCUAUGAUGACCACCAUGAUGAUUAUU
- - - - - - - - - - - - -non translated leader - - - - - - - - - ->|- - - - - - - - - - - - -non translated leader - - - - - - - - - ->|fMet Thr Met Ile ooo ooofMet Thr Met Ile ooo ooo NH NH 2 ---gene z protein-2 ---gene z protein-
-----------------------//------UAA UAG UGA------------------AUG-----(y gene) -//-----UAA------------------------//------UAA UAG UGA------------------AUG-----(y gene) -//-----UAA-
--- ... ----- ... --Aaa Aaa Aaa Aaa Aaa Aaa // // AaaAaa fMet ----------------------COOHfMet ----------------------COOH
----------------------------COOH----------------------------COOH
DNADNA
|- - - - - - -|- - - - - - -promoterpromoter - - - - - - - - - - | - - - - - - - - - - | |------coding-- … |------coding-- … 5’ TC 5’ TC AAATTGTGAGCGGA TAACAATTTAAATTGTGAGCGGA TAACAATTT GA CACAGG AAACAGCT GA CACAGG AAACAGCTATG ACCATGATTATG ACCATGATT----- …----- …
5’ AG5’ AGTTTTAACATTAACACTC GCCT ATCTC GCCT ATTGT TAATGT TAAAA CTGTGT CC TTTG TCGATAC TGGTACTAA CTGTGT CC TTTG TCGATAC TGGTACTAA----- … ----- …
mRNA mRNA purine-rich purine-rich pppAAUUGUGAGCGGAUAACAAUUUGACpppAAUUGUGAGCGGAUAACAAUUUGACACAGGAAACAGACAGGAAACAGCUCUAUGAUGACCACCAUGAUGAUUAUU
- - - - - - - - - - - - -non translated leader - - - - - - - - - ->|- - - - - - - - - - - - -non translated leader - - - - - - - - - ->|fMet Thr Met Ile ooo ooofMet Thr Met Ile ooo ooo NH NH 2 ---gene z protein-2 ---gene z protein-
-----------------------//------UAA UAG UGA------------------AUG-----(y gene) -//-----UAA------------------------//------UAA UAG UGA------------------AUG-----(y gene) -//-----UAA-
--- ... ----- ... --Aaa Aaa Aaa Aaa Aaa Aaa // // AaaAaa fMet ----------------------COOHfMet ----------------------COOH
----------------------------COOH----------------------------COOH
Gene Expression Gene Expression Molecular Molecular BiologyBiology Prokaryotic Prokaryotic operonoperon
Gene Expression Gene Expression Molecular Molecular BiologyBiology Prokaryotic Prokaryotic operonoperonLac operon: promoterLac operon: promoterLac operon: promoterLac operon: promoter
© 1999-2004 by Gene C. Lavers, Ph.D.
6
Gene Expression Gene Expression RegulationRegulation laclac Operon (lactose = glucose + galactose) Operon (lactose = glucose + galactose)
Gene Expression Gene Expression RegulationRegulation laclac Operon (lactose = glucose + galactose) Operon (lactose = glucose + galactose)
[CAP-cAMP] complex = [CAP-cAMP] complex = f f (([cAMP] , when [glucose] is high, [cAMP] is low [cAMP] , when [glucose] is high, [cAMP] is low because glucose is preferred substrate for energy in cell.because glucose is preferred substrate for energy in cell.
High [cAMP] and high [CAP-cAMP] not sufficient to turn gene ON because High [cAMP] and high [CAP-cAMP] not sufficient to turn gene ON because repressor is still bound to o/prepressor is still bound to o/p
If [Lactose] increases, then repressor released from o/p when lactose If [Lactose] increases, then repressor released from o/p when lactose binds repressor, but gene not induced unless [cAMP] is high too.binds repressor, but gene not induced unless [cAMP] is high too.
CAP-cAMP complex binds to CAP site in promoter forming an open CAP-cAMP complex binds to CAP site in promoter forming an open complex increasing access of RNA polymerasecomplex increasing access of RNA polymerase
Transcription of gene yields new mRNA every 2.5 secondsTranscription of gene yields new mRNA every 2.5 seconds About 90 copies of mRNA synthesized per cellAbout 90 copies of mRNA synthesized per cell Ribosomes initiate protein synthesis every 5 seconds on each mRNARibosomes initiate protein synthesis every 5 seconds on each mRNA
about 20 about 20 -galactose chains synthesized/sec = 5 tetrameric molecules-galactose chains synthesized/sec = 5 tetrameric molecules mRNA has half-life of 90 secondsmRNA has half-life of 90 seconds As [lactose] falls in cell, it dissociates from tetrameric repressorAs [lactose] falls in cell, it dissociates from tetrameric repressor Repressor binds to o/p, gene is turned OFFRepressor binds to o/p, gene is turned OFF laclac operon is an repressed gene (OFF) that lactose induces to be ON operon is an repressed gene (OFF) that lactose induces to be ON
[CAP-cAMP] complex = [CAP-cAMP] complex = f f (([cAMP] , when [glucose] is high, [cAMP] is low [cAMP] , when [glucose] is high, [cAMP] is low because glucose is preferred substrate for energy in cell.because glucose is preferred substrate for energy in cell.
High [cAMP] and high [CAP-cAMP] not sufficient to turn gene ON because High [cAMP] and high [CAP-cAMP] not sufficient to turn gene ON because repressor is still bound to o/prepressor is still bound to o/p
If [Lactose] increases, then repressor released from o/p when lactose If [Lactose] increases, then repressor released from o/p when lactose binds repressor, but gene not induced unless [cAMP] is high too.binds repressor, but gene not induced unless [cAMP] is high too.
CAP-cAMP complex binds to CAP site in promoter forming an open CAP-cAMP complex binds to CAP site in promoter forming an open complex increasing access of RNA polymerasecomplex increasing access of RNA polymerase
Transcription of gene yields new mRNA every 2.5 secondsTranscription of gene yields new mRNA every 2.5 seconds About 90 copies of mRNA synthesized per cellAbout 90 copies of mRNA synthesized per cell Ribosomes initiate protein synthesis every 5 seconds on each mRNARibosomes initiate protein synthesis every 5 seconds on each mRNA
about 20 about 20 -galactose chains synthesized/sec = 5 tetrameric molecules-galactose chains synthesized/sec = 5 tetrameric molecules mRNA has half-life of 90 secondsmRNA has half-life of 90 seconds As [lactose] falls in cell, it dissociates from tetrameric repressorAs [lactose] falls in cell, it dissociates from tetrameric repressor Repressor binds to o/p, gene is turned OFFRepressor binds to o/p, gene is turned OFF laclac operon is an repressed gene (OFF) that lactose induces to be ON operon is an repressed gene (OFF) that lactose induces to be ON
Repressed operon = off, must be induced “on”Repressed operon = off, must be induced “on”Repressed operon = off, must be induced “on”Repressed operon = off, must be induced “on”
© 1999-2004 by Gene C. Lavers, Ph.D.
7
Regulation of Gene ExpressionRegulation of Gene Expression Control of Gene Control of Gene ExpressionExpressionTranscription – Posttransciptional Levels Transcription – Posttransciptional Levels
Regulation of Gene ExpressionRegulation of Gene Expression Control of Gene Control of Gene ExpressionExpressionTranscription – Posttransciptional Levels Transcription – Posttransciptional Levels
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.1 MechanismsFig. 32.1 Mechanisms
© 1999-2004 by Gene C. Lavers, Ph.D.
8
Gene Promoter ElementsGene Promoter Elements Control of Gene Control of Gene ExpressionExpressionUpstream TAF binding sequences (boxes)Upstream TAF binding sequences (boxes)
Gene Promoter ElementsGene Promoter Elements Control of Gene Control of Gene ExpressionExpressionUpstream TAF binding sequences (boxes)Upstream TAF binding sequences (boxes)
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.2 MechanismsFig. 32.2 MechanismsFig. 32.2 MechanismsFig. 32.2 Mechanisms
© 1999-2004 by Gene C. Lavers, Ph.D.
9
Response ElementsResponse Elements Control of Gene Control of Gene ExpressionExpressionModulating gene expression Modulating gene expression
Response ElementsResponse Elements Control of Gene Control of Gene ExpressionExpressionModulating gene expression Modulating gene expression
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.3 Specific TF bind to DNA response element Fig. 32.3 Specific TF bind to DNA response element sequences sequences have varying effects on the level of have varying effects on the level of transcription.transcription.
Fig. 32.3 Specific TF bind to DNA response element Fig. 32.3 Specific TF bind to DNA response element sequences sequences have varying effects on the level of have varying effects on the level of transcription.transcription.
© 1999-2004 by Gene C. Lavers, Ph.D.
10
Classes of Domains in TAF Classes of Domains in TAF Control of Gene Control of Gene ExpressionExpressionHTH, HLH, Zn finger, Leucine zipper HTH, HLH, Zn finger, Leucine zipper
Classes of Domains in TAF Classes of Domains in TAF Control of Gene Control of Gene ExpressionExpressionHTH, HLH, Zn finger, Leucine zipper HTH, HLH, Zn finger, Leucine zipper
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.4 For main classes of protein structures Fig. 32.4 For main classes of protein structures that bind that bind to DNA regulation sequences.to DNA regulation sequences.
Fig. 32.4 For main classes of protein structures Fig. 32.4 For main classes of protein structures that bind that bind to DNA regulation sequences.to DNA regulation sequences.
© 1999-2004 by Gene C. Lavers, Ph.D.
11
| . | . || . . || . . || ||
EYRVEYRVRRRRERERNNNINIAAVRVRKKSSRRDDKKAKQRNVEAKQRNVETTQQKQQKVVLELELLTSDNDRTSDNDRLLRKRRKRVVEQEQLLSRELDTSRELDTLL C/EBP C/EBP
EYRQEYRQRRRRERERNNNMNMAAVKVKKKSSRRLLKKSKQKAQDSKQKAQDTTLQRLQRVVNQNQLLKEEKEENNERERLLEAKEAKIIKLKLLLTKELSVTKELSVLL lg/EBP lg/EBP--11 KREVKREVRRLMKLMKNNREREAAARAREECCRRRRKKKKEYVKCKKEYVKCLLENRENRVVAVAVLLENQNKTENQNKTLLIEEIEELLKAKALLKDLYCHKKDLYCHK CREBCREB KRRIKRRIRRRRERERNNKMKMAAAAAAKKCCRRNNRRRRELTDTRRELTDTLLQAEQAETTDQDQLLEDKKSAEDKKSALLQTEQTEIIANANLLLKEKEKLKEKEKLL c-Fos c-Fos KAERKAERKRKRMRMRNNRIRIAAASASKKCCRRKKRRKLERIARKLERIARLLEEKEEKVVKTKTLLKAQNSEKAQNSELLASTASTAANMNMLLREQVAQREQVAQLL c-Jun c-Jun PAALPAALKRKRARARNNTETEAAARARRRSSRRAARRKLQRMKQKLQRMKQLLEDKEDKVVEEEELLLSKNYHLSKNYHLLENEENEVVARARLLKKLVGERKKLVGER GCN4 GCN4
SCRKSSCRKSRRYNYNNNKIKKAKIKKAKKLLRRFFRRHKFVSGQHKFVSGQLLKKSAVMKKSAVMLLDTMRDVDTMRDVIIAQAERQAQAERQLLLERGYPLERGYPAA sis-Asis-A
LMLMRRAIAIRRVFEFVFEFGGGPEVLGPEVLKKLQSDVAVPILQSDVAVPIPPKDHQVLKDHQVLIIKVQAHGKVQAHGVVNPYDTYNPYDTYIIRSGTHNRSGTHNII -cry-cry + + + + + + + + + +
TAFs TAFs + + + + + +
-cry-cry
Basic region
Gene Expression Gene Expression Gene Gene RegulationRegulationTAF domainsTAF domains
Gene Expression Gene Expression Gene Gene RegulationRegulationTAF domainsTAF domains
leucine zipper helix
N C
Leucine ZipperLeucine ZipperLeucine ZipperLeucine Zipper
GeneGene
© 1999-2004 by Gene C. Lavers, Ph.D.
12
Gene Expression 1 Gene Expression 1 OverviewOverviewGenomic InformationGenomic Information
Gene Expression 1 Gene Expression 1 OverviewOverviewGenomic InformationGenomic Information
Hox genes, homeobox, and body patterningHox genes, homeobox, and body patterningHox genes, homeobox, and body patterningHox genes, homeobox, and body patterning
hox genes in mammals, amphibians, insects, worms, yeast … hox genes in mammals, amphibians, insects, worms, yeast … homeo box = 180 bp recurring sequence motif (yellow)homeo box = 180 bp recurring sequence motif (yellow) homeodomain - 60-residue polypeptidehomeodomain - 60-residue polypeptide hox genes arranged in clusters along DNAhox genes arranged in clusters along DNA linear hox genes and clusters correspond to head to foot axislinear hox genes and clusters correspond to head to foot axis hox genes provide patterning of 3D-bodyhox genes provide patterning of 3D-body Expressed HOX PROTEINS trigger body development programsExpressed HOX PROTEINS trigger body development programs Expression gradients sustain growth of organs and limbsExpression gradients sustain growth of organs and limbs HOX proteins are Transcriptional Activator Factors (TAFs)HOX proteins are Transcriptional Activator Factors (TAFs)
5’5’ 3’3’5’5’ 3’3’
© 1999-2004 by Gene C. Lavers, Ph.D.
13
SKRGRTAYTRPQLVELEKEFHFNRYLMRPRRVEMANLLCLTERQIKIWFQNRRM KY KKDNmousemouse
Gene Expression 1 Gene Expression 1 Molecular Molecular GeneticsGeneticsEukaryotic Regulatory GenesEukaryotic Regulatory Genes
Gene Expression 1 Gene Expression 1 Molecular Molecular GeneticsGeneticsEukaryotic Regulatory GenesEukaryotic Regulatory Genes
5’5’
5’5’
RKRKRRGRQTYTRYQTLELEKEFHFNRYLTRRRR I E I AHVLCLTERQIKIWFQNRRM KWKKENGRQTYTRYQTLELEKEFHFNRYLTRRRR I E I AHVLCLTERQIKIWFQNRRM KWKKENfrogfrog
KPKPYYRGHRFTKENVR ILESWFAKNPYLDTKGLENLMKNTSLSR I QIKIWFQNRRR K EK T I TRGHRFTKENVR ILESWFAKNPYLDTKGLENLMKNTSLSR I QIKIWFQNRRR K EK T I Tyeastyeast
-Helix-Helix -Helix-Helix
fruit flyfruit fly RKRKRRGRQTYTRYQTLELEKEFHFNRYLTRRRR I E I AHALCLTERQIKIWFQNRRM KWKKENGRQTYTRYQTLELEKEFHFNRYLTRRRR I E I AHALCLTERQIKIWFQNRRM KWKKEN
Hox genes, homeobox, and homeodomainHox genes, homeobox, and homeodomainHox genes, homeobox, and homeodomainHox genes, homeobox, and homeodomain
|- - - - - - - - - -|- - - - - - - - - - H o m e o d o m a i n H o m e o d o m a i n - - - - - - - - -|- - - - - - - - -|
-Helix-Helix
© 1999-2004 by Gene C. Lavers, Ph.D.
14
GlucocorticoidsGlucocorticoids Control of Gene Control of Gene ExpressionExpressionSteroid Response Element (SREs) Steroid Response Element (SREs)
GlucocorticoidsGlucocorticoids Control of Gene Control of Gene ExpressionExpressionSteroid Response Element (SREs) Steroid Response Element (SREs)
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.5 Steroid-receptor-enhancer Fig. 32.5 Steroid-receptor-enhancer Fig. 32.5 Steroid-receptor-enhancer Fig. 32.5 Steroid-receptor-enhancer
© 1999-2004 by Gene C. Lavers, Ph.D.
15
Zinc Finger DomainsZinc Finger Domains Control of Gene Control of Gene ExpressionExpressionRecognizing the SRE Recognizing the SRE
Zinc Finger DomainsZinc Finger Domains Control of Gene Control of Gene ExpressionExpressionRecognizing the SRE Recognizing the SRE
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.5 Zn fingers allow protein binding to dsDNA. Fig. 32.5 Zn fingers allow protein binding to dsDNA. Fig. 32.5 Zn fingers allow protein binding to dsDNA. Fig. 32.5 Zn fingers allow protein binding to dsDNA.
© 1999-2004 by Gene C. Lavers, Ph.D.
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Protein Homology Protein Homology Control of Gene Control of Gene ExpressionExpressionPalindromes Palindromes
Protein Homology Protein Homology Control of Gene Control of Gene ExpressionExpressionPalindromes Palindromes
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Diet ODiet O2 2 Diet ODiet O2 2
A man a plan a canal panamaA man a plan a canal panamaTCCAGT nnn ACTGGA
Fig. 32.7 DNA-binding domains share a high degree of homology. Fig. 32.7 DNA-binding domains share a high degree of homology. Fig. 32.7 DNA-binding domains share a high degree of homology. Fig. 32.7 DNA-binding domains share a high degree of homology.
© 1999-2004 by Gene C. Lavers, Ph.D.
17
RNA EditingRNA Editing Control of Gene Control of Gene ExpressionExpression
RNA EditingRNA Editing Control of Gene Control of Gene ExpressionExpression
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.8 RNA editing yields tissue-specific mRNA from Fig. 32.8 RNA editing yields tissue-specific mRNA from same gene. same gene. Fig. 32.8 RNA editing yields tissue-specific mRNA from Fig. 32.8 RNA editing yields tissue-specific mRNA from same gene. same gene.
© 1999-2004 by Gene C. Lavers, Ph.D.
18
Iron Response ElementIron Response Element Control of Gene Control of Gene ExpressionExpressionIron Response ElementIron Response Element Control of Gene Control of Gene ExpressionExpression
CarCar CarCar
Diet ODiet O2 2 Diet ODiet O2 2
Fig. 32.9 IRE-BP, iron response element binding Fig. 32.9 IRE-BP, iron response element binding protein. protein. Fig. 32.9 IRE-BP, iron response element binding Fig. 32.9 IRE-BP, iron response element binding protein. protein.
© 1999-2004 by Gene C. Lavers, Ph.D.
19
Control of Gene ExpressionControl of Gene ExpressionControl of Gene ExpressionControl of Gene Expression
ENDENDENDEND
© 1999-2004 by Gene C. Lavers, Ph.D.
20
Control of Gene Control of Gene ExpressionExpression
Control of Gene Control of Gene ExpressionExpression
Not coveredNot covered Not coveredNot covered
Fig. 32.10Fig. 32.10Fig. 32.10Fig. 32.10Fig. 32.11Fig. 32.11Fig. 32.11Fig. 32.11
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