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Flashcards in Gene Regulation Deck (27):
1

Purpose of Gene Regulation

-Give cell specialized role
-Gene product dosage
-Nuclear Envelope
-Respond to changing environmental stimuli
-Different developmental stages

2

Always transcribed/expressed
-Gene product continuously needed to run the cell
ex. GAPDH in glycolysis, rRNA genes, Actin

Housekeeping Genes (Constitutively expressed)

3

Transcription and expression is more regulated.
-Transcribed and translated in response to the needs of the cell.
ex. immune response, development, vasodialators/constrictors, HOX

Conditionally expressed genes (Facultatively expressed)

4

Where does transcription occur?

-Chromosome territory
-Interchromosomal domain
-Transcription factory

5

Each chromosome exists in a defined area of the nucleus.

Chromosome territory

6

Areas of nucleoplasm between chromosomes
-Space

Interchromosomal domain

7

Clusters of transcriptional machinery

Transcription factory

8

-Is essential for transcription
-When bound by GTFs, recruits polymerase and causes basal transcription.
-Other elements fine tune transcription

Core Promoter

9

"next to gene"
consensus sequence

Cis-acting sequence

10

"from someplace else" (away from gene)

Trans-acting sequence

11

Regulatory segments of the eukaryotic gene

-Set of cis acting elements are bound by trans acting factors

12

Regulatory segments of the eukaryotic gene contain:
-Combination of coordinates strength of expression of that gene (can turn up or down gene expression)

-Core promoter
-Proximal elements---close
-Distal elements---far
1. Enhancers
2. Silencers

13

Regulatory Elements

Enhancers
Silencers

14

Bound by activators
Cis regulating element
-When bound, increase transcription of the gene

Enhancers

15

Bound by repressors
-When bound, transcription is decreased and gene expression is repressed.

Silencers

16

Regulation at the transcriptional level is upstream or downstream from the +1 site?

Upstream

17

Have 2 major domains:
1. DNA binding domain
2. Transcription activation domain
-Changing shape

Activators

18

Subset of enhancers
-binding allows for the cell to respond to enviornmental changes by expressing genes involved in that response
ex. ARE (antioxidant response element)

Response Elements

19

Have opposite role of activators
-Decrease transcription

Repressors

20

In response to injunctions from activators, these factors position RNA pol. at the start of transcription and initiate the transcription process

GTFs (General transcription Factors)

21

Each gene has a specific set of regulatory elements that are bound by specific regulatory proteins
-More efficient because no need for more activators

Combinatorial gene regulation

22

To measure expression

Measure amount of products:
1. RNA
2. Protein
Reporter System--located downstream from promoter of interest

23

Histone core is moved so that the gene is accessible to transcription.
-Sliding exposes DNA

Chromatin Remodeling

24

One gene can encode more than one protien because different combinations of exons are spliced together

Alternative Splicing

25

mRNA turnover

-mRNA is degraded in a controlled manner
-Half-life
-Depends on structure of RNA and proteins bound to it and on poly A tail length
-Way to regulate translation of the mRNA transcript

26

mRNA can be stored in such a way that they're not translated right away.
-Speedy
-Good for immediate response, cell can regulate translation

Differential translation

27

-Protein degradation in response to signals

Proteolysis