L10-control of Gene Expression.pdf

CellDifferentiations depend changes in on changes ingene expressions ratherthanon nucleotide sequencesof cell genome c Cells will differenciate gene expression NOT by changes changes on in nucleotide sequence the difference lies in the protein patter proteins can be acidic or basic To separate they...

CellDifferentiations depend changes in on changes ingene expressions ratherthanon nucleotide sequencesof cell genome c Cells will differenciate gene expression NOT by changes changes on in nucleotide sequence the difference lies in the protein patter proteins can be acidic or basic To separate they use gel electrophoresis SD Proteins can according to surface be separated the will unfold proteins on chraarge or 1st dimension the protein on the Surface On the band 2nd dimension they he on separated molecular weight Human brain I Human liver contain the B UT different protein are expressed to show IDENTITY of the tissue same DNA DNA tells how organism develops Proof found through John Guindon Yamanaka an experiment You need DNA to develop 6 Sleeps at which Eukaryotic geneexpression can 1 DNA be controlled Transcription Control Ift mrua armmigIIIinsioni 3 RNA transport Localization control Cettosol it S mRNA degradation control 6 Phelan activity control 4 mRNA protein in in nucleus you make mRNA from DNA cytosol the mRNA is translated into Protein not just but in cytosol can be localized to other locations 5 sometimes mRNA its not needed or so can be damaged it get degraded DNABindingPwter Transcription factors to start transcription thefactors bind to a region called Promotor Gene Regulatory sequences in mammilian seeks sequence can be very long is bacteria not Open frame is ETG so much where translation start codon TAA occurs stop codon RN A polymerase is already there just needs to keep moving transcription factors S 3 DNA binding protein tike transcription factors bind to surface of DNA without unwinding When to you Unwind do DNA Replication B NA needs a When transcription factors Dindthey bind most blind here to mini gvooveormayrgrooue.in DNA Helix Short DNA of sequences genetic switches are fundament components Helix turn Helix motif one of the simplest t most common DNA binding motifs The red helix is the recognition Helix the othe helix is the blue helix that stabilizes the recognition helix Theybindhas of 3 4 mm Dimer Binding at distance Helix turn Helix makes very sharp turn whereas helix loop helix motif is more broad mediates dimerization t DNA binding the iinative domain meds both binding domains or it will not bind to DNA But dimerization still occurs The leucine zipper motif Mediates DNA binding can A Dimerization form Homo dinners Hetero dimer Hetero dinners alter DNA binding specificity Different DNA sequencing Beta sheets can also recognize DNA Study of DNA binding proteins 1 Gel mobility shift assay detects sequence specific DNA binding proteins DNA is G charged t migrates to G electrodes Hydrophobic The phosphates on IN A Surface make it negative Free DNA will migrate quickly through the gel DNA with Proteins will migrate slowly qq.ema.nlfnITfnpYoi adolose for small pieces doesn't Degrade DNA it's a native gel large pieces Youcantellifproterubindsorint Doesn't say 2 where it binds DNA foolprinting tells where proteinbinds Nuclease chops DNA Protein protects are it covers Poly gel 3 DNA affinity Chromatography purity DNA birding proteins Doesn't tell you whatis going on in the living DNA binding is ionic salt washes will disrupt 20W salt wash removes proteins that do not bird medium salt wash many different DNA binding proteins Then whats left GGceGcg over medium salt will wash all proteins not specific to I Then high salt proteins to goes to step 2 only bind to will elute qGC rare 4 Chromatin immuno percipitation Shows where a protein or protein complex location binds to specifically its a cell toonspecific chromosome How By adding cross a linking agent formaldehyde it freezes the protein immobilizing protein the DNA interaction in living cell Then through Sonification youfragment the DNA proteins remain attached by crosslink Next fragmented you add antibody once that associates w a specific specificprotein Then using PCR polymerase chain reaction Because you cant see when so you amplify the DNA amount little I auro This technique will tell you where S4 protein specifically bind onto DNA whats This one tells cell going on in living you Prokaryotic toEukaryotic Greve Expression Prokaryotic Gene Expression prokaryotic bacteria don't just contain isingle gene they're Lpolycishonic 1 mRNA encodes MULTIPLE protein done no on an operon need for coodinertion in DNA Eukaryotic Gene Expression Single proteins r single genes are expressed Switching ftp.tophan ON OFF r t.GE OF.rnrs polymerasebonds Isi No Whentryptophan present triptormfite inactive repressor d sorties EkgHocking thepolymerase frombinding 2 types Negative Regulation Bound Repressor protein prevents Transcription Positive Regulation Bound activator protein promotes transcription Lac operon Lactose is composed of Glucose 8Galactose Lac operon codes proteins required to transport the sugarlactose into the cells break it down Glucose is 1 Step to a cleave first carbon the source Galactoseand Glucose Lae operon if there the operon is if there is is no Lactose present off by no a repressor glucose present Catabolite Activating Protein CAP senses low levels of glucose and activates the operon Shows different transcription factors binding at the time same Gene control for Eukaryotic Genes consists of promoterplus regulatory sequences since so large and complex a Mediator protein complex is needed to establish interactions Denteen components Most G ones in Eulaaryds are made by RNA.to ymerase ranscriptionalSynergY means if there is 1 protein binding to the DNA it will activate small amount of transcription if theres another protein it is there another prooe it will activate small amount BUT if they both tied to DNA it will amplify it A LOT Eukaryotic Gene Regulatory Protein don't bind as single proteins but mostly as complexes To integrate the multiple inputs of DNA Looping is required and contributes to gene activation promotor at The a distance activation Domain f DNA binding domain don't need to match whats important the regoonition the is making sure Sequence of DNA matches DNA binding domain Regulating Transcription single gene regulatory protein ears coordinate the expression of several different a genes since DNA is negatively charged and histones are 4 DNA wraps tightlyaround the histones trowing chromatin tightly wrapped transcription factors need to bind somehow since so You need Chromatin that will Remodeling Complex open the chromatin Chromatin Remodling Complex can do many things remodel nucleosomes histone removal histone replacement Specificportemrhistonemodificati Done by histonemodifyingcomplex Events leading to Transcription initiation by remodelingof chromatin or modifying i 2 Masking the activation Surface 3 Direct factors interaction with general transcription 4 Recruitment of chromatin Remodeling complex Recruitment of Histonedeacetylase Remove stimulus for transcription Histones contain postwietly chargered G amino acids putting acetylation groups fr move Make chromatin Histone Deacetylase move compact on Histonewill open CHAT will make chromatin 6 Recruitment of Histone methy transferase make the histones tighten Barrier sequence to separate in active DNA Prevents spreading of the Heterochromatin insulator element separate in active at some active transcriptions genes that other point can from be active Inheritance of Methylated DNA Epigenetic inheritance Ability for a in an organism daughter cell to retain the gene expression patterns that were present in the parent cell memory of fimportant to keep cell identity Mechanisms that can produce a form epigenetic inheritance 1 f Positive feedback loop can create cell memory protein A might not be made but a signal activates it Thesignal creates a memory that is passedalong of a L S memory usedalong 2 Histone Modification 3 DNA Methylation X chromosome inactivation females 2 xdromosomsfsiIEIGIEIE.ms ne Post translational From control 1 mRNA you RNA editing can produce various proteins