Transcriptional Regulation

Question 1

Housekeeping genes

Answer 1

Are single copy genes that are high in number but low in transcriptional level

Question 2

Tissue specific gene

Answer 2

Are highly repetitive genes that are low in number but high in transcriptional level

Question 3

Regulation of gene expression

Answer 3

Transcriptional
Post-transcriptional
Translational
Post-translational
Most frequently gene expressions is at transcriptional level

Question 4

Control mechanism

Answer 4

Negative control
Positive control

Question 5

Prokaryotic gene regulation

Answer 5

Negative control
—repressor
—corepressor
—inducer
Positive control
—activator
—coaktivator
Antitermination
Attenuation

Question 6

Prokaryotic positive control

Answer 6

When glucose level is low the enzyme Adenylyl Cyclase is activated then caMP(cyclic adenosine monophosphate)is synthesized.cAMP activates CAP (catabolite activator protein)/CAP is TF and activated CAP binds to its own region and activates RNA polymerase

Question 7

Antitermination

Answer 7

RNA sentezini normal bir şekilde sonlanmasını engelleyen protein

Question 8

Attenuation

Answer 8

Kademeli azaltma

Question 9

Prokaryotic Translational stage

Answer 9

Autogenous control
—inhibition of transcription or translation by the end-product of gene itself
Anti-sense RNA
—inhibition of transcription or translation
—degradation of mRNA by endonucleoses

Question 10

Antisense RNA

Answer 10

Bir hücrede mRNA dizgisini tamamlayan tek sarmallı RNA

Question 11

Eukaryotic gene regulation

Answer 11

Transcriptional stage
Initiation of transcription
—cis acting factor:(affect gene expression only same chromosomal allel)
Promoter
Enhancer( güçlendirici)
Silencer(susturucu)
LCR(locus control region)
insulator(yalıtkan)
—trans acting factor:(binds to DNA)
Transcription factors
“”General transcription factors
“”Regulator transcription factors

Question 12

Modification of chromatin structure

Answer 12

—Histon acetylation/deacetylation
—chromatin remodeling
—DNA methylation

Question 13

Sıralama ökaryot

Answer 13

—Gene activator protein binds to chromatin(chromatin remodeling complex)
—chromatin remodeling(histon modification enzymes)
—covalent histon modification(other activator proteins)
—Additional activator proteins bound to gene regulatory region(mediator +general transcription factors RNA polymerase)
—assembly of pre-initiation complex at the promoter(other gene activator proteins +rearrangement of proteins in the pre-initiation complex
—transcription initiation

Question 14

Post-transcriptional level EUAKARYOTES

Answer 14

➢ Alternative splicing
➢ Alternative polyadenylation
➢ mRNA editing

Question 15

Translational level ökaryot

Answer 15

➢ mRNA transport
➢ translation initiation and elongation factors ➢ polyA tail
➢ mRNA structure
➢ mRNA stability
➢ – AU rich element (ARE): AUUUA

Question 16

Post-translational level ökaryot

Answer 16

➢ glycosylation
➢ acetylation
➢ phosphorylation
➢ methylation Protein degradation

Question 17

Prokaryotic negative control

Answer 17

The function of trp operon is to synthesize tryptophan

The repressor binds to operator and inactivates transcription. In this case tryptophan binds to repressor so tryptophan is a “co-repressor”. When repressor is inactive it can’t bind to the operator so transcription is activated.)