13'1 The cell cycle is an ordered series of events leading to the replication of cells

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13.1 The cell cycle is an ordered series of
events leading to the replication of cells
Figure 13-1
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Regulated protein phosphorylation and degradation
control passage through the cell cycle
Figure 13-2
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13.3 Conformational changes induced by cyclin
binding and phosphorylation increase MPF activity
Figure 13-14
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13.2 Ubiquitin-mediated degradation of mitotic
cyclins promotes exit from mitosis
Figure 13-8
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13.2 Regulation of APC activity controls
degradation of cyclin B
Figure 13-9
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13.4 APC controls entry into anaphase and exit
from mitosis
Figure 13-19
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13.4 Phosphatase activity is required for
reassembly of the nuclear envelope
Mostly cdc20/APC destruction of cyclin (note
this is a feedback loop as M-Cdk activates
cdc20/APC)
Figure 13-20
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G1 stable Cdk inactivity

• Hct1/APC destroys cyclins, inhib. by M-Cdk by
  G1/S Cdks
• CKIs inhibitors f Cdks, inhib. by Cdk activity
• Decreased cyclin production

Note G1 Cdk not blocked by Hct1/Apc or CKIs
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13.5 Multiple cyclins direct kinase activity of
Cdc28 during different cell-cycle phases
Budding yeast START
Figure 13-26
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13.5 Three G1 cyclins associate with Cdc28 to
form S phase-promoting complex
S. cerevisiae Cdc28 is functionally equivalent to
S. pombe Cdc2
Figure 13-23
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13.5 Experimental demonstration that G1 cyclins
regulate entry of S. cerevisiae into S phase
Figure 13-24
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Vertebrates
Budding Yeast
G1-Cdk cyclinD Cdk4,6 Cln3 Cdk1 G1/S-Cdk cycli
nE Cdk2 Cln1,2 Cdk1 S-Cdk cyclinA Cdk2 Clb5,6
Cdk1 M-Cdk cyclin B Cdk1 Clb1-4 Cdk1
D1,D2,D3 in mammals Cdc2 (vertebrates, fission
yeast), Cdc28 (budding)
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Mammalian Restriction Point
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Cyclin D is requiredto pass restriction point
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13.6 Regulated expression of two classes of genes
returns G0 mammalian cells to the cell cycle
Figure 13-30
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13.6 Passage through the restriction point
depends on activation of E2F transcription factors
Mammalian cyclin-kinase inhibitors also
contribute to cell cycle control
Figure 13-31
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13.5 Degradation of the S-phase inhibitor Sic1
triggers DNA replication
Figure 13-25
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13.5 Replication at each origin is initiated only
once during the cell cycle
Figure 13-27
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13.7 Checkpoints in cell cycle regulation
Figure 13-34
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13.7 G1 and G2 arrest in cells with damaged DNA
depends on the p53 tumor suppressor
Figure 13-35
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13.7 The mechanism of p53-induced cell-cycle
arrest in response to DNA damage
Mdm2 ubiq. P53 DNA damage-gtphosph. of
p53-gtprevents Mdm2 binding
Note for G2, also 1-4-33 activation, inhibits
cdc25 ppase
Figure 13-36
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