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confused about transcription

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crazy250

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Does transcription factors and transcription factor binding motif affect the level of gene expression? I know you need TFs to start transcription, but does it affect the LEVEL of gene expression? If not, what does affect the level of gene expression? Thanks for any serious responses.
 

CH3CH2OH

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hmm, that's probably not the best answer, but the question is pretty complicated...
first, a TF (TBP-TATA Binding Protein) has to bind to the TATA box, the more similar it is to the consensus sequences, the higher the possibility of binding. another factor is of course the activators such as hormones, their presence affects the activity of the transcription factors, and repressors - for the same reason.
i'm not sure about the motifs... but many TFs have more than one...
 

UCLAstudent

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Originally posted by crazy250
Does transcription factors and transcription factor binding motif affect the level of gene expression? I know you need TFs to start transcription, but does it affect the LEVEL of gene expression? If not, what does affect the level of gene expression? Thanks for any serious responses.

Yes, definitely. A TF that has a stronger binding affinity for the promoter/enhancer will result in that gene being transcribed more often. If the TF only has moderate or weak affinity, the gene will not be transcribed as often.
 

ASDIC

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the level of gene transcription is affected by the altered processivity of the RNA Polymerase. This alteration can result from the interaction of enhancers and repressors.

The TBP in the TFIID complex is only for RNA Polymerase recruitment. So it will not affect the level of transcription. The activators too are used in the RECRUITMENT.

So, there are various enhancers that promote hyperacetylation of the CTDs of DNA strands that cause them to open up more. Repressors are the oppposite ==> they decrease acetylation of the CTDs.

So remember: if acetylation increases, level of DNA transcription also increases.
 

TripleDegree

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I'm curious - is this stuff that you guys are talking about .... (motifs etc) in either the Kaplan or EK books? If so - I'd be hugely grateful if you could point me to a specific page number in either of these books!


I'm stressin!
 

UCLAstudent

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The stuff about the TATA box and enhancers/promoters should be in ANY MCAT prep book. The stuff that thekegalman said is just to prove the point/answer the OP's question. You don't have to know that much detail for the MCAT. :)
 

ASDIC

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yeah...you dont have to all the details...stick with the basics.

I got all excited since i am a molecular biology major
 

ASDIC

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CH3CH2OH

is not a carbohydrate as indicated in the name/icon/location combo

Its an alcohol...and will not participate in the energy yielding reactions.
 
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