Lecture 4 Questions Flashcards
What are the functions and properties of a promoter?
Initiates transcription
Controls gene expression
Binds RNA polymerase
Specific to genes
Contains conserved sequences (e.g., TATA box)
Upstream of gene
Varies in strength
Responsive to signals
What is the ATP used for during transcription inititation?
Promoter recognition
DNA unwinding
What is the helicase that is needed during transcription initiation, what does it do, and what is it
good for?
Promoter recognition
DNA unwinding
What is the relevance of RNA Pol II pausing? What is the advantage of regulating transcription at this stage?
The body is able to rapidly respond to signals without the need of initiation etc. (immune response /cell differentiation)
What may be the advantage of having such a complex mechanism of transcription initiation (for example, multi-step assembly of multi-subunit protein complexes)?
Regulation of gene expression at precise timepoints/ factors
Quality control
Flexibility
What do enhancer and promoters have in common, and what are the differences?
They are both regulatory regions that interact with DNA-binding proteins to regulate gene transcription
Differences: Location Promoters are next to transcription start site
Enhancers are far away from promoter
Promoters are gene specific and enhancers can act on multiple genes
What are the mechanisms by which sequence specific transcription factors can activate
transcription?
Chromatin Remodeling
Mediator Complex Recruitment
Co-activator Recruitment
How can fine-tuning of transcriptional regulation be achieved?
By several transcription factors working in tandem / co-activators/repressors
What are the characteristics of super-enhancers, as compared to regular enhancers?
High density of TF binding sites
High gene expression
Specific histone modifications
