Describe two proteins phosphorylated by the M phase cyclin-dependent kinase (M-Cdk). What does the phosphorylation of...

Describe two proteins phosphorylated by the M phase cyclin-dependent kinase (M-Cdk). What does the phosphorylation of that protein cause?

Expert Solution

M phase cyclin dependent kinases, once activated by dephosphorylation drives the entry of cell in mitotic phase.. M-cdk alone does almost all the work necessary for mitosis.

Following are 2 primary targets of M cdk during mitosis

Condensins

Condensins are class of proteins responsible for condensation of chromatins. Condensins can form a ring like structure and use energy obtained from ATP hydrolysis in compacting sister chromatids.

M- CDK helps in condensation of sister chromatids by phosphorylating condensin subunits and hence triggers the coiling and condensation of DNA led by phosphoylated condensin proteins.

Lamin proteins

Lamins are important fibrous proteins. They are responsible for structural rigidity of nuclear membrane. Lamins are also responsible for degradation and reassembly of nuclear membrane along with positioning of nuclear pores.

Dismantling of nucler membrane is another key step during cell division. M-cdk triggers dissolution of cell membrane by phosphorylating laminin proteins and thereby triggereing it's depolymerization.

Apart from these proteins M- cdk also plays pivotal role in assembly and stabilization of spindle fibres. Therefore it is M cdk which triggers sismantling of nuclear membrane, condensation of sister chromatids alongwith assembly of spindle fibres.

gladiator answered 2 years ago

Which of the following is not true about cyclin-dependent kinase (CDK): a. It’s present only during...

Which of the following is not true about cyclin-dependent kinase (CDK): a. It’s present only during the M phase of the cell cycle b. When CDK is combined with cyclin, the MPF (Mitosis Promoting Factor) formed initiates mitosis c. It’s a protein that controls other proteins using phosphate groups d. It’s present at all times during the cell cycle

Cyclin and Cdk proteins control the cell cycle, with different combinations of cyclins and Cdks being...

Cyclin and Cdk proteins control the cell cycle, with different combinations of cyclins and Cdks being activated at different times in the cycle. How does the combination of adding and removing phosphates regulate M cyclin-Cdk complex activity?

What sorts of mutational changes could occur in a gene for a cyclin-dependent kinase might lead...

What sorts of mutational changes could occur in a gene for a cyclin-dependent kinase might lead to a cell becoming cancerous? Be as specific as you can as to what effect the mutational change would have on the kinase protein.

How does M-Cdk facilitate mitosis? (Hint: 4 targets) How is M-Cdk turned off? Explain what happens...

How does M-Cdk facilitate mitosis? (Hint: 4 targets) How is M-Cdk turned off? Explain what happens in telophase related to the M-Cdk targets and return of cell to interphase.

Does phosphorylation of a signaling protein by an upstream kinase represent a signaling input or output?...

Does phosphorylation of a signaling protein by an upstream kinase represent a signaling input or output? Explain.

Describe how cdc2 kinase activity is controlled by interacting with Cyclin, cdc25, CAK and by phosprylation/dephosphorylation.

A mutation in the liver enzyme PFK-2/FBPase-2 results in the loss of cAMP-dependent kinase phosphorylation site,...

A mutation in the liver enzyme PFK-2/FBPase-2 results in the loss of cAMP-dependent kinase phosphorylation site, thus resulting in a loss of responsiveness to cAMP-dependent kinase. What are the effects of this mutation on blood glucose levels during times of fasting? Please explain your answer.

an important checkpoint regulator is at the gap2/m-phase transition. here cyclin B and cdk1 activate and...

an important checkpoint regulator is at the gap2/m-phase transition. here cyclin B and cdk1 activate and form MPF which becoes a ________ two words and causes the DNA to condense into_____

A.) List two general ways that phosphorylation by a kinase can promote intracellular signaling? B.) Explain...

A.) List two general ways that phosphorylation by a kinase can promote intracellular signaling? B.) Explain why, in the absence of inhibitor, epinephrine stimulation results in the presence of beta arrestin band, which is absent in inhibitor treated samples.

Describe mechanisms by which ion channels, protein phosphorylation and G-proteins give cells an ON or OFF...

Describe mechanisms by which ion channels, protein phosphorylation and G-proteins give cells an ON or OFF response for cell signaling. Describe this for each of these three processes, in the specific prompts below. Be sure be clear about where these mechanisms are distinct from one another. What are the inactive and inactive states? How does signal input activate the system? How is the system returned to inactive state?

Question