A briefe history of the cell cycle
Download
1 / 55

A briefe history of the cell cycle - PowerPoint PPT Presentation


  • 90 Views
  • Uploaded on

18xx Interphase-Mitosis 1951 Discovery of a distinct S-phase 1970 Cell fusion experiments 1971 Discovery of MPF 197x Yeast cdc mutants 1983 Discovery of the first cyclins 1988 Cyclin B+cdc2 = MPF 199x Ubiquitin and the cell cycle 1999 Sister chromatid separation.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' A briefe history of the cell cycle' - raffaello-payton


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
A briefe history of the cell cycle

18xx Interphase-Mitosis

1951 Discovery of a distinct S-phase

1970 Cell fusion experiments

1971 Discovery of MPF

197x Yeast cdc mutants

1983 Discovery of the first cyclins

1988 Cyclin B+cdc2 = MPF

199x Ubiquitin and the cell cycle

1999 Sister chromatid separation

A briefe history of the cell cycle


The most important role of cell cycle control is to ensure accurate chromosome segregation
The most important role of cell cycle control is to ensure accurate chromosome segregation

M

G2

G1

S


A briefe history of the cell cycle

General principles and methods

G1 - To cycle or not to cycle

S- Replicating the genome

M-Segregating the genome

Cytokinesis - Making two cells















Cyclins and cyclin dependent kinases cdks in budding yeast

Cln1,2,3

G1

Cyclins and cyclin dependent kinases (cdks) - in Budding yeast

Clb5,6

Cdk1

(cdc28)

(S.p. cdc2)

S

G2

Clb3,4

M

Clb1,2


Cyclins and cyclin dependent kinases cdks in multi cellular organisms

G1

Cyclin D1,2,3

Cyclin E

Cyclin A

S

Cyclin A

Cyclin B1,2,3

M

Cyclins and cyclin dependent kinases (cdks) - in multi-cellular organisms

Cdk4,6

Cdk2

Cdk1

(S.p. cdc2)


Cdc2 28 cdk1 is regulated by
Cdc2/28 (=cdk1) is regulated by:

1. Binding of a cyclin2. Inhibitory phosphorylation3. Activating phosophorylation4. Binding of CKI5. Cellular localization


A briefe history of the cell cycle

G1 - To cycle or not to cycle

S- Replicating the genome

M-Segregating the genome

Cytokinesis - Making two cells


A briefe history of the cell cycle

E2F

P

E2F

P

E2F

E2F

E2F

P

E2F

E2F

E2F

P

G1

Cyc D

cdk4

S

P

pRB

Cyc E

cdk2


A briefe history of the cell cycle

G1 - To cycle or not to cycle

S- Replicating the genome

M-Segregating the genome

Cytokinesis - Making two cells


A briefe history of the cell cycle

The human genome is encoded by 3,000,000,000 bp (3x109) which must all be replicated within a few hours with the highest fidelity. The loss of a bp is irreversible and a single mistake could potentially lead to the death of the organism.


Analogy
Analogy

One page contains about 3000 letters.

Imagine that you have to copy one million pages in a few hours and have to bind them into 23 volumes.

You can use as many typist as you like but you are allowed no mistakes -no missing letter, no letter twice, and no substitutions.


A briefe history of the cell cycle

G1 - To cycle or not to cycle

S- Replicating the genome

M-Segregating the genome

Cytokinesis - Making two cells


The story of the two blind men
The story of the two blind men

  • Two blind men go into a shop and buy each five different pairs of socks. Unfortunately all ten pairs were packed in the same bag.

  • How can the two men separate the socks so that each of them will get five pairs ?


The three factors that enable sister chromatid separation
The three factors that enable sister chromatid separation

  • The glue - cohesins

  • The pulling force - the mitotic spindle

  • The timing mechanism - spindle checkpoint


The three factors that enable sister chromatid separation1
The three factors that enable sister chromatid separation

  • The glue - cohesins

  • The pulling force - the mitotic spindle

  • The timing mechanism - spindle checkpoint


A briefe history of the cell cycle

Check

Separase

Check

APC

Separase

Separase

Separase

point

Securin

Securin

point

Cohesin

Cohesin

prometaphase

metaphase

anaphase

Sister chromatid separation from prometaphase to anaphase

APC

Ub

Ub

Ub

Securin


A briefe history of the cell cycle

Non-degradable securin does not prevent cytokinesis

but interferes with complete chromatide separation

histon-GFP

Hoechst

NIH3T3

HeLa

securin

securin

KAA-DM

securin

KAA-DM


The three factors that enable sister chromatid separation2
The three factors that enable sister chromatid separation

  • The glue - cohesins

  • The pulling force - the mitotic spindle

  • The timing mechanism - spindle checkpoint


A naphase p romoting c omplex c yclosome
Anaphase Promoting Complex/Cyclosome

APC/C

Cyclosome


A briefe history of the cell cycle

Checkpoint

Checkpoint

Checkpoint

Cyclin B

cdk1

Prophase

Polo

P

P

P

APC

P

P

P

P

Fzy

Fzr

P


A briefe history of the cell cycle

Checkpoint

Checkpoint

Checkpoint

P

P

P

P

P

P

P

Cyclin B

cdk1

Metaphase

Polo

APC

Fzy

Fzr

P


A briefe history of the cell cycle

Metaphase

Anaphase

Polo

P

P

P

P

P

Cyclin B

P

P

P

cdc14

APC

Fzr

cdk1

Fzy

Fzy

Fzr


A briefe history of the cell cycle

Substrate

Role

Active

Degradation

initiated

Degrad. essential

Cyclin A2

Kinase (+cdk1/2)

S, G2, prophase

Prometaphase

Yes (metaphase)

Nek2A

Kinase

G2, prophase

Prometaphase

Yes (cyclin A+B degr.)

Securin

Chromatid cohesion maintenance

S-metaphase

Metaphase

Yes (chrom. separation)

Cyclin B1

Mitotic kinase

Prophase- metaphase

Metaphase

Yes (cytokinesis)

Xkid

Chrom. alignment on metaphase plate

Metaphase

Metaphase

Yes (chrom. movement)

Plk1

Mitotic kinase

Mitosis

Telophase - G1

?

Fzy

APC/C activator

Metaphase

Telophase - G1

No

UbcH10

E2 of the APC/C

Mitosis

Telophase

?

Cdc6

Replication

S

G1

No