Molecular Genetics - Ch. 15 Learnsmart

Repressors inhibit TFIID by

- preventing the binding of TFIID to the TATA box - inhibiting the ability of TFIID to recruit RNA polymerase II to the core promoter

Transcription factors that affect the ability of RNA polymerase to begin the transcription process may work by __________.

- regulating the binding of the transcriptional complex to the core promoter - control the switch from the initiation to the elongation stage of transcription

What are the most common ways that the functions or regulatory transcription factors are controlled?

- the binding of a small effector molecule - protein-protein interactions - covalent modifcations

A repressor interacting with mediator prevents ________.

RNA polymerase to proceed to the elongation phase of transcription

motif

a domain that has a very similar structure in many different proteins

Mediator phosphorylates the ________-terminus of RNA polymerase II, stimulating progression to the _______ stage of transcription.

carboxyl ; elongation

Activator proteins often increase transcription through an interaction with _____________.

coactivators

In general, transcriptional regulation is aimed at __________.

controlling the initiation of transcription at the promoter

Glucocorticoid response elements are located near _________ genes.

dozens of different

Steroid hormones are synthesized by ____________ glands and secreted into the bloodstream, ultimately affecting the transcription or expression of genes in target cells.

endocrine

A glucocorticoid response element functions as a(n) _____________.

enhancer

Activators bind to ____________.

enhancers

The transactivation domain of coactivators promotes the activation of RNA polymerase, often by interacting with ___________.

general transcription factors

A domain called an alpha-_________ is often found in transcription factors because it is the proper width to fit into the _______ groove of the DNA double helix

helix ; major

Most eukaryotic genes are regulated by __________ factor(s).

many

Activator proteins stimulate the ability of __________ to phosphorylate the carboxyl-terminus of RNA polymerase II, which facilitates the switch between transcriptional initiation and elongation.

mediator

Following the binding of a hormone, two glucocortcoid ________ form a dimer and travel to the _________.

receptors ; nucleus

The phenomenon where the level of gene expression is controlled so that genes can be expressed at high or low levels is called gene _____________.

regulation

The cAMP ________ element-binding protein (__________ protein) is a regulatory transcription factor that is activated in response to signaling molecules that increase cytoplasmic cAMP.

response ; CREB

Repressors bind to _________.

silencers

Which stops can gene regulation occur?

transcription, RNA processing, translation, and posttranslational

T or F: a transcription factor can have multiple domains

true

T or F: the function of regulatory transcription factors is modulated

true

The cAMP response element (CRE) contains ________ of a consensus sequence bound by the CREB protein, which has ___________.

two copies ; two identical subunits

DNA sequences in eukaryotes that can be bound by regulatory transcription factors, which then affect the ability of RNA polymerase to transcribe a particular gene are called ____________.

regulatory elements, control elements, regulatory sequences

Regulatory transcription factors that respond to steroid hormones are called __________.

steroid receptor

Proteins that regulate the rate of transcription of target genes are called __________ transcription factors.

regulatory

The CREB protein binds to DNA at a sequence called the cAMP ___________.

response element