Limits...
Using default constraints of the spindle assembly checkpoint to estimate the associated chemical rates.

Dao Duc K, Holcman D - BMC Biophys (2012)

Bottom Line: Our purpose is to use these opposed constraints to estimate the associated chemical rates.We compute the probability for no APC/C activation before time t, the distribution of Cdc20 at equilibrium and the mean time to complete APC/C activation after all chromosomes are attached.By studying Cdc20 inhibition and the activation time, we obtain a range for the main chemical reaction rates regulating the spindle assembly checkpoint and transition to anaphase.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Biology (IBENS), Group of Computational Biology and Applied Mathematics, Ecole Normale Supérieure, 46 rue d'Ulm 75005 Paris, France. holcman@ens.fr.

ABSTRACT

Unlabelled: :

Background: Default activation of the spindle assembly checkpoint provides severe constraints on the underlying biochemical activation rates: on one hand, the cell cannot divide before all chromosomes are aligned, but on the other hand, when they are ready, the separation is quite fast, lasting a few minutes. Our purpose is to use these opposed constraints to estimate the associated chemical rates.

Results: To analyze the above constraints, we develop a markovian model to describe the dynamics of Cdc20 molecules. We compute the probability for no APC/C activation before time t, the distribution of Cdc20 at equilibrium and the mean time to complete APC/C activation after all chromosomes are attached.

Conclusions: By studying Cdc20 inhibition and the activation time, we obtain a range for the main chemical reaction rates regulating the spindle assembly checkpoint and transition to anaphase.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the Markov Chain associated with the joint probability pk,m(t) to have k bounds APC/C and m free Cdc20 molecules.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3368725&req=5

Figure 4: Schematic representation of the Markov Chain associated with the joint probability pk,m(t) to have k bounds APC/C and m free Cdc20 molecules.

Mentions: From the state (k,m), the transition rate to activation of APC/C located on another kinetochore is then μ(k - m)(N - m). Thus, we get the following Markov chain (represented in figure 4)


Using default constraints of the spindle assembly checkpoint to estimate the associated chemical rates.

Dao Duc K, Holcman D - BMC Biophys (2012)

Schematic representation of the Markov Chain associated with the joint probability pk,m(t) to have k bounds APC/C and m free Cdc20 molecules.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3368725&req=5

Figure 4: Schematic representation of the Markov Chain associated with the joint probability pk,m(t) to have k bounds APC/C and m free Cdc20 molecules.
Mentions: From the state (k,m), the transition rate to activation of APC/C located on another kinetochore is then μ(k - m)(N - m). Thus, we get the following Markov chain (represented in figure 4)

Bottom Line: Our purpose is to use these opposed constraints to estimate the associated chemical rates.We compute the probability for no APC/C activation before time t, the distribution of Cdc20 at equilibrium and the mean time to complete APC/C activation after all chromosomes are attached.By studying Cdc20 inhibition and the activation time, we obtain a range for the main chemical reaction rates regulating the spindle assembly checkpoint and transition to anaphase.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute for Biology (IBENS), Group of Computational Biology and Applied Mathematics, Ecole Normale Supérieure, 46 rue d'Ulm 75005 Paris, France. holcman@ens.fr.

ABSTRACT

Unlabelled: :

Background: Default activation of the spindle assembly checkpoint provides severe constraints on the underlying biochemical activation rates: on one hand, the cell cannot divide before all chromosomes are aligned, but on the other hand, when they are ready, the separation is quite fast, lasting a few minutes. Our purpose is to use these opposed constraints to estimate the associated chemical rates.

Results: To analyze the above constraints, we develop a markovian model to describe the dynamics of Cdc20 molecules. We compute the probability for no APC/C activation before time t, the distribution of Cdc20 at equilibrium and the mean time to complete APC/C activation after all chromosomes are attached.

Conclusions: By studying Cdc20 inhibition and the activation time, we obtain a range for the main chemical reaction rates regulating the spindle assembly checkpoint and transition to anaphase.

No MeSH data available.


Related in: MedlinePlus