Random shit to memorize week 1 Flashcards
(69 cards)
1
Q
AZT inhibits…? and treats?
A
- AZT inhibits reverse transcriptase - nucleoside analog that terminates the chain
- Treats HIV
2
Q
Cisplatin
A
alkylating agent used as a chemotheraputic
3
Q
Actinomycin D
A
Intercalates with DNA, interferes with normal base pair stacking
4
Q
Doxorubicin
A
Intercalates with DNA
Blocks DNA replication
5
Q
Puromycin
A
-mimics amino-acyl tRNA to terminate translation
6
Q
Dysteratosis congenita
A
telomere deficiency syndrome
7
Q
Acyclovir targets…
A
viral DNA polymerase
8
Q
Quinolones target…
A
bacterial DNA gyrase
9
Q
Herditary non-polyposis colorectal cancer (Lynch Syndrome) caused by a mutation in ________
A
MMR
10
Q
hMSH and hMLH proteins used in _________ and act to __________
A
- MMR
- recognize new strand damage (via methylation and knicks) leading to cut in front of and behind damage
11
Q
Specific DNA glycolases
A
used in BER to recognize damaged base in DNA sequence and excise it, thus exposing the AP site
12
Q
Global Genome NER uses ________ protein to recognize damaged DNA and recognizes DNA _____________
A
XPC protein
recognizes damage anywhere in the genome
13
Q
Mutations on Global Genome NER can result in ____________ and ____________
A
Cancer, Xeroderma Pigmentosum (XP)
14
Q
TFIIH is involved in which kind of DNA repair
A
NER - XPB and XPD subunits unwind DNA
15
Q
Transcription coupled NER uses _____ and ______ proteins to recognize damaged DNA and repairs DNA in ____________ regions
A
CSA and CSB to recognize damaged DNA
repairs DNA in transcribed region
16
Q
Mutations on Transcription coupled NER can result in __________ and __________
A
CNS disorder, Cockayne syndrome (CS)
17
Q
PARP is activated in what repair pathway?
A
single-strand break repair
amplifies damage singnal
18
Q
RNA polymerase I makes…
A
makes rRNA
19
Q
RNA pol II makes…
A
makes mRNA, small nuclear RNA, and micro RNA
20
Q
RNA pol III…
A
makes tRNA
21
Q
C-terminal Domain (CTD)
A
- acts as a landing pad for proteins that effect elongation/processing during transcription
- Present in RNA pol II
22
Q
CTD is phosphorylated by ______ to allow RNA pol II to elongate RNA chain
A
CDK7 subunit of TFIIH
23
Q
a-amanitin is a _________ that acts on/binds __________ to block __________
A
- non-competitive inhibitor
- RNA pol II (bridge helix)
- RNA pol II translocation and thus transcription
24
Q
Rifampicin blocks _________ by ________
A
- blocks growth of RNA chain in transcription
- by binding to the exit channel in RNA pol II
25
TFIID
aka TATA Binding Protein
- general transcription factor
- Binds TATA box on the DNA sequence
26
TFIIH (3 subunits)
- general transcription factor
- functions in transcription and DNA repair (NER)
- CDK7, XPB, XPD
27
XPB and XPD subunits of TFIIH act to ______
act as helicases that open up DNA strands (closed --> open complex in transcription)
28
Syndromes associated with mutations in TFIIH (3)
Xeroderma pigmentosum (XP)
Cockayne’s Syndrome (CS)
Trichothiodystrophy (TTD)
29
3 reactions to add 5' cap to pre-mRNA
1) Triphosphatase: removal of phosphate group
2) Guanylytransferase: adds guanine and synthesizes 5'-->5' bond
3) Guanine 7-methyltransferase: adds methyl group at 7 position of guanine
30
4 Functions of mRNA cap
1) Protects the 5’ end from exonucleases
2) Recognized by cap-binding complex, which helps with splicing and processing
3) Recognized by translation factor eIF4E (eukaryotic initiation factor 4E) for nuclear export into cytoplasm
4) Removal of cap signals mRNA degradation
31
Abnormal _______ of CD44 contributes to _________
splicing
| tumor metastasis
32
Spinal muscular atrophy results from a defective ________ gene, but can be possible treated by ________ in order to activate the _______ gene in its place
- defective SMN1
| - alternative splicing --> SMN2 can take its place
33
Two functions of the mRNA polyA tail
1) protection from degredation
| 2) export from the nucleus
34
Two types of thalassemias, what is thalassemia, which one is worse
Thalassemia is anemia
1) Beta-Thalassemia
2) Gamma-Delta-Beta Thalassemia (worse)
35
Beta Thalassemia is caused by a mutation in the ________ of the b-globin gene and results in _________
- Mutation in the promoter region
| - results in less promotion and thus less transcription
36
Gamma-Delta-Beta Thalassemia is caused by a _________ in the b-globin gene and results in ________
- mutation in splice site
- results in NO globin transcription
- very severe anemia
37
Hemophilia B-leyden results from a mutation in the _________ of the clotting protein gene, but can be partially recovered why?
- promoter region
| - Partially better at puberty due to some overlap of TFs of androgen receptors
38
Fragile X-syndrome results from a mutation in __________ to increase _________ upstream of FMR1 gene causing ________
- mutations in DNA control elements
- CG repeats
- abnormally high methylation and transcriptional silencing
39
What are the 4 families of sequence specific DNA binding proteins?
1) Hemeodomain (helix-turn-helix)
2) Zinc-finger
3) Basic Leucine Zipper
4) Helix-loop-Helix
40
Homeodomain sequence specific DNA binding proteins are typically used for ___________
regulation of development
41
the _______ family of SSDBP tend to form dimers
Basic leucine zipper
42
Craniosynostosis results due to a mutation of the MsX2 protein at the __________ that causes MsX2 to ________ and results in ___________
- at the DNA binding homeodomain
- bind the DNA more tightly
- gain of function, protein transcribed at higher level
43
Androgen insensitivity syndrome is caused by a mutation in the ____________ resulting in _________
- androgen receptor (zinc-finger protein) DNA binding domain OR ligand binding domain
- decreased response to androgens
44
Waardenburg Syndrome is caused by a mutation in the MITF gene that encodes a ____________ that regulates melanocyte development
basic helix-loop helix binding domain
45
Two classes of chromatin remodeling factors
1) ATP-dependent chromatin remodelers
| 2) Histone Modifying enzymes
46
ATP-dependent chromatin remodelers
Use ATP hydrolysis to break histon-DNA contacts to move histone octomer along DNA in order to allow TFs access to sites on DNA
(SWI/SNF)
47
Histone Acetyltransferase (HAT)
- acetylates histone tails
- neutralizes + charge on lysine
- allows DNA to be less tightly wound
- transcriptional activator
48
Histone deacetyltransferase (HDAC)
- removes acetyl group
| - transcriptional repressor
49
Rubinstein Taybi Syndrome results from a CBP haploinsufficiency. This effects ________
HAT activity --> effects transcription of multiple gene targets
50
Fragile X syndrome results from methylated DNA that recruits in ________ that ________
HDACs
| silence transcription in that area
51
Euchromatin
where genes reside that are actively transcribed (accessible area of chromatin)
52
Heterochromatin
always repressed because DNA is inaccessible (at centromeres, telomeres, and some internal chromosomal positions
53
Constitutive Heterochromatin
always heterochromatin
54
Facultative Heterochromatin
can change to euchromatin depending on cell type or developmental stage
55
Ways to regulate sequence specific DNA binding proteins (5)
1) Control protein conformation by binding a ligand
2) regulate entry into the nucleus
3) Regulate amount
4) Regulate binding to DNA
5) Phosphorylate SSDBP to alter properties
56
Estrogen hormone binds to ________, inducing _______ and activating __________
Estrogen receptor
dimerization of ER
transcription by binding to the DNA
57
Tamoxifen is a drug that binds to _______ preventing _________
- the estrogen receptor
| - prevents recruitment of HATs, inhibits transcription
58
MDM2 protein acts on p53 to... (2 mechanisms for this)
Inhibit transcription of p53 genes
- via ubiquination that marks p53 for degredation
- by binding activation domain of p53
59
Over-expression of MDM2 protein can cause _________
low levels of p53 and thus cancer/tumor growth
60
Cyclosporin is an immunosuppressant that ____________ by ______________
inhibits transcription by sequestering the sequence specific DNA binding protein in the cytoplasm
61
Id protein prevents _________ of _______ proteins, thus ___________
heterodimerization of helix-loop-helix proteins, thus inhibiting binding to the DNA
62
_______ of the CREB binding protein allows CREB to ________
phosphorylation
| recruit pol II transcription machinery
63
NF-kappa-B
- Sequence specific DNA binding protein
| - involved in inflammation
64
When I-kappa-B protein is bound to NF-kappa-B, NF-kappa-B is ___________. During inflammation conditions, I-K-B protein is ________, allowing NF-K-B to ____________
- sequestered in cytoplasm
- Phosphorylated and degraded
-allowing NF-K-B to bind and enhance transcription of inflammatory response genes.
65
Aspirin
inhibits degredation of I-K-B protein, so it remains bound to NF-K-B, and sequestered in the cytoplasm
66
NF-ATc
- Sequence Specific DNA binding protein
| - involved in immune response
67
Calcineurin acts on NF-ATc to ___________, allowing NF-ATc to _____________
remove phosphate group from NF-ATc
enter into the nucleus and activate transcription
68
Cyclsporin
- immunosuppressant drug
| - inhibits calcineurin activation, so NF-ATc remains phosphorylated in the cytoplasm
69
B-Catenin is ____________ by APC. If APC is mutated then there is ___________ B-Catenin resulting in abnormal cell growth/cancer
phosphorylated/degreaded
a surplus of B-Catenin that can then get into the nucleus
