Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Molecular Medicine > Gene Expression > Flashcards

Gene Expression Flashcards

0
Q

Three domains of a transcription factor

A

DNA binding domain
Activation domain
Ligand binding domain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Three stages of transcription

A

Initiation
Elongation
Termination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Transcription factor categories based on DNA binding/dimerisation domains

A 
Helix loop helix - myc
Lucine zipper - AP 1
Zinc finger - steroid receptor
Helix turn helix 
Homeodomain (helixloophelixturnhelix) - Hox
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Activation of transcription factors can be constitutive or regulatory. What are the subsets of regulatory?

A

Developmental(cell specific)

Signal dependent -> steroid receptors, internal signals, cell surface receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Transcription factors bind..

A

Response elements in promotor region

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

TFs function by:

A

Stabilizing preinitiation complex
Recruiting co-activators
Altering chromatin
[can be negative as well]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Three tests that measure gene expression

A

Microarray
Northern blot
qRT-PCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Tests to study gene expression

A 
Promotor reporter assays
Nuclear run on assays
Binding assays
In vitro > EMSA, DAI
In Vigo > Chromatin immunoprecipitation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Steps followed when doing EMSA

A
  1. Obtain nuclear extract
  2. Incubate with radiolabelled probe of binding domain
  3. Run on PAGE
  4. Develop and detect on film
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Steps to microarray

A
  1. Isolate mRNA
  2. Generate cDNA (RT)
  3. Label the two samples with different probes
  4. Hybridise onto assay
  5. Imaging
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Steps of capping and methylation

A
  1. Gamma phosphate hydrolysed off 5’ triphosphate of mRNA (phosphohydrolase)
  2. Guanylyl transferase covalently joins GTP to RNA chain
  3. Methyl transferase methylated guanine at the N-7 position
  4. Can be further methylated CAP0>CAP1>CAP2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Capping catalysed by three enzymes

A

Phosphohydrolase
Guanylyl transferase
Methyl transferase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why have a cap? (And polyA tail)

A

Promotes stability of mRNA
Prevents degradation by 5’ exonucleases
Promotes translation of mRNA
Helps to recruit mRNA to ribosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Two steps of polyadenylation

A

Cleavage: RNA cut 10-30 nucleotides down from AAUAAA

Addition of As: 100-200 added (no template needed)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What adds polyA tail

A

PolyA polymerase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Sequence of branch site in intron

A

YNYRAY

Y = pyrimidine
R = purine
N = anything
16
Q

What forms the spliceosome?

A

snRNP

Pre-mRNA

17
Q

What makes up snRNPs

A

snRNA - small 100-200 ntds, rich in Us

10 different proteins

18
Q

Importance of snRNAs

A

Mediate sequence specificity/accuracy
Fold into 2ndry structures - stem loops
Catalyse splicing

19
Q

Central outcome of alternative splicing

A

One gene can produce multiple mRNAs and proteins

20
Q

Additional RNA processing events

A

Trans splicing of exons from different mRNAs
mRNA editing
Transport to cytosol

21
Q

RNA degradation in eukaryotes

A
  1. Shortening of PolyA tail
  2. Removal of 5’ cap
  3. 5’ to 3’ exoribonuclease
22
Q

RNA instability elements

A

ARE elements - A/U rich elements

23
Q

Steps in microRNA pathway

A 
The miRNA fold back on itself
Enzyme DICER cuts it into short segments
One strand of dsRNA degraded
Other strand complexes with proteins
Complex can target any complementary sequence
Prevents gene expression
24
Q

Stages of translation

A

Assembly of initiation complex AUG
Subunits of ribosome binds
Translation begins
Elongation of polypeptide chain

25
Q

Examples of translational control

A

MicroRNA
Iron response element binding protein
RNA masking

26
Q

Post translational modifications of proteins

A 
Phosphorylation/dephosphorylation
Ligand and co-factor binding
Protein protein interaction
Protein degradation
Peptide cleavage
Etc
27
Q

Applications of microarray

A

Track gene expression patterns associated with disease
Identify gene as diagnostic markers/ therapeutic targets
Identify changes in gene expression in response to targets

28
Q

Why prepare cDNA from mRNA

A

More stable
Used to quantify expression levels -> RT-PCR
Used for expression profiling , mircoarrays

Molecular Medicine (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions