14: Transcription regulation (eukaryotes)

T or F. general transcription factors are required at every polymerase II promotor

true

The control of gene expression requires _

chromatin remodeling

T or F. Every gene requires activation to be transcribed.

t

Most eukaryotic promoters are (positively / negatively) regulated.

positively

Access to eukaryotic promoters is restricted by the structure of _

chromatin

_ are commonly involved in eukaryotic transcriptional regulation

long noncoding RNA’s

chromatin is in _ form to undergo gene regulation

euchromatin

Most eukaryotic promoters are _ regulated.

positively

In eukaryotes, every gene requires _ to be transcribed

activation

proteins involved in transcription in eukaryotes

1. Transcription activators

2. Architectural regulators

3. Chromatin modification and remodeling proteins

4. Coactivators (Mediator)

5. Basal transcription factor

regulatory sites can be far from the promotor in eukaryotes / prokaryotes

eukaryotes

zinc-finger is (DNA-binding / activation) domain

dna binding

leucine zipper is (DNA-binding / activation) domain

dna binding

helix loop helix is (DNA-binding / activation) domain

dna binding

glutamine-rich domain is (DNA-binding / activation) domain

activation

proline-rich domain is (DNA-binding / activation) domain

activation

outline transcription activation

1. binding of activator to enhancers

2. recruitment of coactivators and histone modification, mediator

3. recruitment of TBP

4. recruitment of basal transcription factors and poly II

5. HMG proteins

3 types of activation domain

(less focused on structure than dna-binding)

leucine are (hydrophilic / hydrophobic)

hydrophobic

true or false. removing activation region can turn the lacz off

true

true or false. adding activation region can turn the lacz on

true

types of alterations in chromatin

1. covalent modification

2. structural modification

outline covalent modifications

heterochromatin → euchromatin

• histone acetyltransferase (like lysine)

• acetylates chromatin

outline structural modifications

changes accessibility of binding sites in DNA to proteins by remodeling nucleosomes

• loosens promoter region

• chromatin remodeling complex

mediator complex is a type of _

coactivator

function of architectural regulators (high mobility group proteins)

high mobility group proteins that help bend DNA to move enhancer closer to promotor

_ mediates the silencing of many genes

microRNAs

receptor can be repressed by binding to _ to turn off transcription

lncRNA (long noncoding rna)

_ is a technique used to silence posttranscriptional genes and turn them off

RNA interference

outline gene expression regulated by steroid hormone (nuclear) receptor

• nuclear receptors have heat shock protein

• when steroid hormone binds to receptor, it dissociates from heat shock protein → dimer

• activated receptor binds to DNA site → transcription to turn on gene

• binding to long noncoding RNA can repress transcription