Strand 4 - Cell cycle Flashcards

1
Q

the cell cycle requires high…… to ensure stable inheritance?

A

fidelity

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

which 3 types of cells are found in the G0 phase?

A

terminally differentiated cells
quiescent cells
senescent cells

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

CDKs are protein kinases which transfer what group onto substrates?

A

a phosphate group

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

what are CDKs activated by?

A

cyclin proteins

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

what does APC/C trigger the degradation of?

A

M cyclin

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

give 2 examples of upstream kinases/phosphatases which are cdk regulators?

A

CAK and Cdc25

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

give an example of a CDK inhibitory protein

A

p27

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

APC/C signals to M cyclin to do what?

A

end mitosis and initiate cell division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

APC/ is a …… ligase. It covalently attaches …… to M cyclin

A

ubiquitin ligase

attaches ubiquitin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does SGF signal for the degredation of to promote G1-S transition?

A

degradation of CKIs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does SGF attach to CKIs?

A

ubiquitin

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

what does mitogen promote the synthesis of?

A

G1-S cyclin

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

if there is DNA damage to the cell, what does the G2 checkpoint inhibit?

A

cyclin activity via CKIs

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

if a chromosome is detected as unattached by the M phase checkpoint, what is prevented?

A

M cyclin destruction

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

what drives the transition from G1 to S phase?

via activating which molecule?

A

active G1-CDK via mitogen activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does the G2 checkpoint check for?

A

if replication is complete, if DNA damage has been repaired, if cell is large enough,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does the mitotic checkpoint check for?

A

if chromosomes are attached to spindle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

if the M phase checkpoint is satisfied, which molecule is activated, causing the degredation of M-cyclin therefore?

A

APC/C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

if checkpoints in the cell cycle cannot be satisfied cells can :

A

exit cell cycle terminally
start apoptosis
withdraw from cycle -> senescence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what does abherrant mitogen signalling cause to cells?

A

drives cells through the G1 checkpoint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what can defects in the mitotic checkpoint cause to chromosomes?

A

aneuploidy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

which mutation causes cancer predisposition syndrome?

A

BubR1 mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

which cell type have stopped proliferating?

A

nerve cells/neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

which 2 receptors can mitogens bind to?

A

EGFR / HER2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
when mitogens bind to either EGFR or HER2, which signalling cascade is triggered? give an example of a gene this pathway causes to be activated
Ras - Raf - MapK pathway Myc
26
Which cyclin gene does Myc upregulate? which CDK can this cyclin gene then bind to and activate?
cyclin D gene bind to CDK 4 / 6 (G1-CDK)
27
Which protein does G1-CDK target?
Retinoblastoma protein
28
which txn factor does retinoblastoma protein bind to?
E2F
29
which cyclins does E2F upregulate? these cyclins can then bind to CDK2 to form what?
E and A G1-S CDK and S-CDK
30
what do **double stranded breaks** in DNA activate, causing the **prevention of G1-CDK **progression **into S phase?**
ATM/R, Chk1/2
31
which CDK does p21, a CKI, inhibit?
G1/S-CDK
32
which cell structure is duplicated in S phase, as well as DNA?
centrosomes
33
do eukaryotes have one or multiple ORICs?
multiple
34
function of the SSBPs in DNA replication?
help strands separate
35
what does DNA primase do in replication?
initiates polymerisation
36
what do topoisomerisases do in replication?
remove supercoils
37
function of sliding clamp in DNA replication?
keeps polymerase on DNA
38
function of DNA ligase in replication?
joins okazaki fragments
39
telomeres are repeating units of what combo of bases?
GGGTTA
40
telomeres extend which end of a chromosome? 5' or 3'?
3'
41
damaged DNA bases cause the helix to become what?
distorted
42
NHEJ is performed when what is detected?
DNA breaks
43
where is info used from to repair DNA breaks if the cell is in S or G2?
a sister chromosome
44
p53 inhibits which CDK?
M-CDK
45
which 2 types of division occur during meiosis?
reduction division then an equational division
46
during which phase of mitosis does the nuclear envelope begin to disappear?
prometaphase
47
during metaphase, what attaches to the sister chromatids?
microtubules
48
during ....... chromosomes condense?
prophase
49
during which phase of mitosis does the bi-orientation of the chromosomes on bipolar spindle occur?
metaphase
50
the contractile ring which starts to contract during telophase, is made up of which 2 components?
actin and myosin
51
entry to mitosis is driven by which CDK?
M-CDK
52
Which 2 downstream mitotic kinases does M-CDK regulate?
aurora and polo kinases
53
the kinetochore is the binding site on a chromosome for what?
microtubules
54
kinetochore proteins are recruited by which 2 kinases in **early mitosis?**
M-CDK and Aurora B
55
in prophase: cohesin is........ condensin is.....
cohesin removed (from chromosome arms) condensin recruited
56
what is the function of cohesin molecules in prophase?
to hold 2 sister chromatids together
57
......... 1 and 2 co-operate to condense chromosomes in mitosis
condensins
58
microtubules are nucleated at which end?
minus end
59
microtubules can grow and shrink at which end?
the plus end
60
give an example of a nucleating protein in microtubules
y-TuRC
61
give an example of a microtubule adaptor protein (MAP)
Ndc80 or Nuf2
62
what are the 2 motors, allowing cell components to move along microtubules?
kinesin -5 dyenin
63
which ends of microtubules does kinesin walk to?
plus ends
64
which end of microtubules does dyenin walk to?
minus ends
65
what does kinesin-5 form which allows it to crosslink with microtubules?
dimers
66
which molecule moves kinetochores towards the cell equator?
CENP-E
67
which kinase detects bi-orientiation via detecting levels of tension (a mechanism not fully understood yet)?
aurora B
68
what does aurora B phosphorylate to remove microtubules from kinetochores?
Ndc80
69
what does the spindle checkpoint detect?
unattached kinetochores
70
which complex do unattached kinetochores produce, which inhibits APC/C, keeping the cell in mitosis?
MCC
71
which complex is no longer produced once all kinetochores are occupied with microtubules?
MCC
72
the coordinated degredation of which two molecules ensures that biochemical exit from mitosis and the onset of anaphase chromosome movements occur together?
M-cyclin and securin
73
during which phase of mitosis do condensins dissociate and cohesins re-associate?
telophase
74
which two things in normal stem cells, does asymmetric cell division balance?
proliferation and cell cycle termination
75
cell **intrinsic** ACD occurs in which type of cell?
neuroblast
76
cell extrinsic ACD occurs in which type of stem cell?
male germline stem cells
77
which two model organisms are ACD core mechanisms learned from?
c elegans and drosophila
78
polarization can be either microtubule or....... dependent?
RHO1
79
polarization in a drosophila neuroblast can be either from the ........ or the previous division
neuroectoderm
79
which group of proteins causes the polarisation of the c.elegans zygote?
PAR proteins
80
the positioning of mitotic spindle in all animals is controlled by the molecular machine, composed of which 3 molecules?
NUMA LGN Dyenin
81
which protein at the anterior side of the cell promotes the degradation of the germ plasm proteins, ensuring somatic specification?
MEX-5
82
Which protein directs the localization of staufen, prospero and brat?
miranda
83
what is an inhibitor of notch signalling?
numb
84
when protooncogenes are mutated, what do they mimic? what do they stimulate?
a stuck accelorator stiumulating abherrant cellular growth and division
85
what is the chromosomal instability linked with cancer?
aneuploidy
86
what happens to chromosomes following DNA ds breaks?
they are translocated or rearranged
87
what are the causes of aneuploidy in mitosis? (write out)
- inappropriate kinetochore-microtubule attachments - compromised SAC - centrosome overduplication - problems with chromosome cohesion - tetraploidy due to cytokinesis failure
88
aneuploidy occurs in which 3 cells?
hepatocytes, neural progenitors and neurons
89
how can cancer cells tolerate aneuploidy? (3 ways)
- lowering DNA damage response - increase replication stress tolerance - prolonged mitosis
90
which trisomy is associated with increased proliferation?
trisomy 12
91
in which type of cancer do trisomies confer a selective advantage upon stress such as hypoxia?
colorectal
92
which chimeric protein is the cause of chronic myeloid leukemia?
BCR-ABL
93
what happens to the protooncogene ABL when a cell is forced into the cell cycle?
it is aberrantly activated
94
name 3 agents which promote ds DNA breaks, increasing the risk of chromosome translocations in cancer
topoisomerase 2 poisons radiation CIN
95
ABL is associated with which chromosome in chronic myeloid leukemia?
9
96
BCR is associated with which chromosome in chronic myeloid leukemia?
22
97
what drug is used for the treatment of ABL (chronic myeloid leukemia)?
imatinib
98
the production of which protooncogene promotes cell proliferation and survival in BCR-ABL signalling?
MYC
99
the deletion and frameshift mutations that lead to loss of Rb function are observed in which type of tumours?
retinal
100
Rb inactivation predisposes patients to defects in which cell growth pathway?
p53
101
what are the 3 types of protooncogenes associated with the Rb pathway?
growth signals Wnt cytokines
102
what is Rb?
retinoblastoma = an eye tumour
103
what are the two types of retinoblastoma? in which type of retinoblastoma are both eyes affected by tumours and the retinoblastoma is inherited?
sporadic and familial familial = both eyes (high risk of other cancers)
104
through the transcription of what.....Rb leads to CIN and aneuploidy?
E2F
105
cancer cells have a high tolerance to what?
chromosome instabilities