m phase cycle

Which are the cyclin a and cdk of m phase

Cdk1 and cycB

Mpf

Maturation promoting factor which dck1 and cyclin B

How do cdk1 become active

1. Phophrylation by cak at threonin 161

2. But still not active because wee1 is phophrylating tyr15

3. DEphosohprilation by cdc25 of tyr15

4. Active!

To aqctivate the complex WHA DOES CAK DO AND WHAT DOES CDC25 DO?

CAK phophorylates threonin 161

Cdc25 dephophorilates the previuosly phophorylated tyr15 by wee1, activating the complex

Cdk1 activates which steps of mitosis?

Which tipes of kinases help control mitosis

2. Chromosomal condensation

3. Nuclear envelop ebreak down in prometaphase

4. Spindle formation in prophase and cytoskeleton reorganization

5. AURORA and polo

Which kinase are actiated in a loop and help regulate mitosis

Cdk1 actiates aurora which activates polo which activates cdk1

The cdk1 and aurora and polo kinase have 4 main function what is necessary for this functions from

A. Chromatin condensation

Nuclear envelope break down

Fragmentation of golgi

Spindle formation

A.phophoprilation of condensin and cohesins

Ph. Of lamins

Pjh. Of golgi matrix protein

Ph. Of kinetochroe and centrosome

What is the role of condensin ? And of cohesin? What actvaes tthem

Aurora polo cdk1 phophorilates them

Condensin: compact chromosomes

Choesin: allow sister chromatis to stay toghter

DURING MITOSISI CONDENSIN IS REPLEACED BY COEDIN

What i sncessary to break down the nuclear envelope

1. The nuclear lamina depolarizes npc dissociates PHOPJ. OF LAMINS

THE GOLGI BREAK DOWN IS MEDIATED BY

POLO ( NO AURORA9 AND CDK1 vescicles are the result of the frag,entation and are abosrbed into the er

The mitotic spindle formation is mediated by?

Aurora and polo

Chromosome attach to spindle at kinetochrore

The riorganization of the cytoskeleton makes the microtubules be dynamically instable what does this mean

That microtube TURNOVER RATE increases and this make the interphase microtube depolymerize

The number of microtubules radiating from the centrosome increases

WHAT IS MCC

Spindle assembly checkpoin ( MITOTIC CHECPOINT COMPLEX9

What is necessary to go to anaphase? What has to be active?

In oder to go to anaphase you need chromosomes perfectly aligned even one stops everything

Apc/c HAS TO BE ACTIVE TO GO TO ANAPHASE

What is inhibited by MCC if there are problems of alignment

Apc/c is inhibited beacuse normally apc ( anaphase promotic complex)

How do the chrosomes separate and move to opposite pole during anaphase? What is process that leads to degradation of choesin?

APC/C UBIQUITINATES CYCLIN B AND SECURIN

SECURIN INHIBITS CDK1

SECURIN ACTOIVATES SEPARASE

SEPARASE DEGRADATES COHESIN

What is the role of separase and who activates it

Separase degaradtes cohesin so the link between sister chromatids i no longer present

Separase is activaed by securin

WHEN CAN WE SAY THAT MITOSIS IS COMPLETED

When cyclins are degradated by apc>/c and also aurora and polo kinase are degradated

The cell exits mitosis and goes to interphase again

When is apc high and when is cdk high

Apc and cdk ( inversamente proporzionali)

Anaphase and g1 HIGH APC. Low cdk activity/ cyclins

G2 and metaphase low apc high cyclins

WHO DISACTIVATES APC/C at end of g1?

Cdk2/ cyclin E

When are cyclin high

Dala sintesi del dna alla mitosis s, g2, m

What activates cytokinesis and how doe sthe contractile ring work

1. Cytokinesis is activated by THE DISACTIVATION OD CDK1 , aurora and polo

2. RhoA( gptase) is activated rho activated kinases as rock allows mlck phophorilation ( myosin light chain kinase) so MYOSIN II IS Activated

3. Rho a also allows the activation of FORMIN which allows the formation of actin filaments and toghter the assemble and form the contractile actin and myosin ring

How are in cytokinesis myosin II filaments activated

BY DISACTING CDK1 aurora and polo

RhoA is activates by kinase rho GEF

Rho Activating kinase activates MLCK which actin myosin II