Download presentation

Presentation is loading. Please wait.

Published byKhalid Rosten Modified over 2 years ago

1
Agonists and Antagonists APC T cell agonist peptide APC T cell antagonist peptide agonist peptide stimulation suppressed

2
Agonists and Antagonists APC T cell agonist peptide agonist peptide stimulation suppressed Dueling positive and negative feedbacks

3
Agonists and Antagonists APC T cell APC agonist peptide stimulation suppressed Dueling positive and negative feedbacks T cell activation (concentration of pErk) Antagonist concentration Scaling ? Agonist concentration D. Wylie, JD, A. K. Chakraborty, PNAS (2007) M. Artomov, JD, M Kardar, A. K. Chakraborty, PNAS (2007)

4
+ve -ve Minimal Model Irreversibility Branching Feedback with distinct time scale 3 species model: Minimal Model for cell signaling with positive and negative feedbacks [X]+[Z]=M=const

5
+ve -ve Minimal Model Irreversibility Branching Feedback with distinct time scale 3 species model: Minimal Model for cell signaling with positive and negative feedbacks [X]+[Z]=M=const Mean field Analysis initial values (t=0) : Rate equations : number conservation :

6
+ve -ve Minimal Model Irreversibility Branching Feedback with distinct time scale 3 species model: Minimal Model for cell signaling with positive and negative feedbacks [X]+[Z]=M=const stability: no un-stable mode Mean field Analysis Solutions:

7
+ve -ve Minimal Model Irreversibility Branching Feedback with distinct time scale 3 species model: Minimal Model for cell signaling with positive and negative feedbacks [X]+[Z]=M=const Mean field Analysis Mean field Scaling:

8
+ve -ve Minimal Model Irreversibility Branching Feedback with distinct time scale 3 species model: Minimal Model for cell signaling with positive and negative feedbacks [X]+[Z]=M=const Stochastic Fluctuations Master Equation: Gain-Loss equation for probabilities of states n For a simple reaction: thus,

9
Effects of Stochastic Fluctuations Master Equation: Exactly Solvable 3 species model: Generating function: Solution:

10
Effects of Stochastic Fluctuations Master Equation: Exactly Solvable 3 species model: Generating function: Solution: [X]+[Z]=M=const small N small k 3 Fixed k 3 /N Stochastic Analysis Mean field large N large k 3 Fixed k 3 /N purely stochastic origin of bimodality

11
Effects of Stochastic Fluctuations Master Equation: Exactly Solvable 3 species model: Generating function: Solution: [X]+[Z]=M=const Origin of Stochastic Bistability Z X rate 2 rate 1 Z d ~ 1/(k 3 n y ) f ~ 1/(k 2 n x n y n z ) ff dd P( ) (activation) (de-activation)

12
Effects of Stochastic Fluctuations Master Equation: 3 species model: Generating function: Solution: ff dd P( ) ff dd reduction of n y and k 3 ff dd P( ) ff dd reduction of n y and k 3 discrete particle number stochastic fluctuations [X]+[Z]=M=const Scaling analysis (in the limit, ) k3k3 mean field scaling variable different from

13
Cell Decision Mediated by Stochastic Fluctuations agonist antagonist Signaling product No signal M. Artyomov, JD, M. Kardar, A. Chakraborty PNAS (2007)

Similar presentations

OK

Oxidation and Reduction Lecture 9. Law of Mass Action Important to remember our equation describes the equilibrium condition. At non-equilibrium conditions.

Oxidation and Reduction Lecture 9. Law of Mass Action Important to remember our equation describes the equilibrium condition. At non-equilibrium conditions.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

View ppt on ipad free Ppt on law against child marriages Ppt on inhabiting other planets in our solar Human body systems for kids ppt on batteries Viewer ppt online student Structural analysis in reading ppt on ipad Ppt on honge oil for sale Ppt on limits and derivatives Ppt on 500 mw turbo generator design Ppt on service oriented architecture and the cloud