Term
| Importance of gene regulation |
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Definition
| All cells inherit same genes so regulation of expression is what makes cells different from one another. |
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Term
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Definition
| Like DNA poly it's 5'-3' but RNA poly can start de novo. Sigma segment in e. coli finds the right sites to bind to. |
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Term
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Definition
| Site where RNA poly binds to start transcription of a gene. -10 and -35 = binding sites. +1 = transcription start site. |
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Term
| Transcription by E. coli RNA poly |
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Definition
| Poly floats along RNA strand till it finds the right site using sigma. RNA poly unwinds DNA near the poly. Sigma dissociates and poly moves along strand, creating RNA, till it hits a stop signal. |
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Term
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Definition
| Shown in E. coli lac operon. Lac is expressed only when lactose is present. Repressor molecule binds to sequence and physically stops poly from transcribing. If lactose is present the lactose molecules bind to the repressor protein, change its shape, and it can't bind to sequence so poly can transcribe gene. |
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Term
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Definition
| Lac operon in E. coli is activated when glucose isn't present. Adenylyl cyclase recognizes when glucose is low, uses ATP to bind cAMP to CAP (catabolite activator protein) which is an activator to make poly transcribe the lac operon. |
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Term
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Definition
| Synthesizes mRNA, miRNA (critical regulators of gene expression), long non-coding regulatory RNAs and snRNA. |
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Term
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Definition
| Synthesizes rRNA 5.8S, 18S, 28S |
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Term
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Definition
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Term
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Definition
| Synthesizes mitochondrial genes |
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Term
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Definition
| Synthesizes chloroplast genes |
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Term
| Formation of RNA poly II pre-initiation complex |
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Definition
| Different genes have different combos of promoter elements. Promoter elements recognized by TFIID and TFIIB, not pol II. TFIIH brings helicase and CTD kinase. CTD pol tail = 52 7-base repeats in humans. |
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Term
| RNA pol II/Mediator complex |
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Definition
| Mediator facilitates basal transcription AND interaction of pol w/regulatory factors. CTD tail is originally attached to to Mediator, then it gets phosphorylated which breaks the connection so pol can break away and transcription starts. Elongation/processing factors then bind to CTD tail to make sure that it doesn't get stuck. |
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Term
| ID of eukaryotic regulatory sequences |
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Definition
| Plasmid w/gene of interst, ori, drug resistance, Ampf, put into animal cells. Stably incorporated cells will be drug resistant and can be selected that way. ALSO plasmid w/regulatory sequence and reporter gene (firefly luciferase), put into cells, and transfected cells will glow! |
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Term
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Definition
| Herpes virus thymidine kinase gene. +1 = transcription start site. -25 = TATAA box. -50 = GC box. -75 = CAT box. -100 = GC. |
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Term
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Definition
| Normal promoter w/ GC boxes and TATA box. There's also a series of 72-bp repeats which is the enhancer. Enhances how much RNA is produced. Can be placed anywhere in strand, sequence of repeats can even be reversed. |
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Term
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Definition
| No matter where the enhancer is along strand, the amount of RNA is increased exponentially. |
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Term
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Definition
| Enhancers can be >50 kb away from promoters in mammal cells because the DNA can loop and bring the enhancer into proximity w/the promoter so they can touch. Looping is caused by Mediator and cohesin associated w/the enhancers/promoters. |
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Term
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Definition
| Is what maintains association of the two sister chromatids during mitosis. Also helps the enhancer and promoter associate w/each other during transcription. |
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Term
| Why doesn't an enhancer work on just any promoter? |
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Definition
| Insulators divide chromosome into distinct looped domains and restrict action of enhancers. Enhancer can act on any promoter w/in its domain. |
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Term
| The immunoglobin enhancer |
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Definition
| ~200 bp, contains multiple binding sites for different transcription factors which work cooperatively to enhance. |
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Term
| Representative transcription factor binding sites |
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Definition
| Can't ID functional sites just from DNA sequence because the sequences found randomly occur throughout the strand w/out functional activity. |
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Term
| Chromatin immunoprecipitation |
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Definition
| To determine transcription factor binding sites in living cells. Treat cells w/formaldehyde and sonicate to make chromatin frags. Cross-link DNA of chromatin frags w/transcription factors. Immunoprecipitate w/antibody against transcription factor of interest (protein, antibody can be used). Collect chromatin/antibody complex. Reverse cross-links to purify DNA, sequence the DNA, now we know what the sequence is for the transcription factor binding site. Use PCR to amplify certain sections of the frag until you find the exact segment that binds the transcription factor. Large-scale DNA sequencing allows for genome-wide binding site analysis. |
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