[seminar] Seminar na IF-u, 26. kolovoza 2014. u 15:00h

[Niksa Krstulovic]

Institut za fiziku, Bijenička cesta 46, 


predavaonica u zgradi Mladen Paić 

utorak, 26. kolovoza 2014., u 15:00 sati 








Physical limits of the accuracy of cell chemotaxis 

Dr. sc. Igor Šegota 

Department of Physics, Cornell University 
E-mail: igs0001 at gmail.com 



A fundamental problem in the study of living matter is how and with what precision single cells measure and orient themselves along extracellular chemical gradients. Eukaryotic cells can accurately sense very shallow gradients where the difference in cell receptor occupancy between the front and the back of the cell is only few molecules. This implies that their sensing performance approaches limits set by basic physical principles. In particular, the stochastic processes of binding and unbinding of these molecules to cell receptors have recently been suggested as the main limiting factor. However, despite the advances in chemical identification of the involved molecules, it is still an open question how parameters such as the total receptor number per cell and the affinity of binding sites for these molecules affect the limits of gradient sensing. I will show how a combination of quantitative experiments and statistical mechanics demonstrates that cells surprisingly acquire much more information about the gradient than allowed by contemporary models of their physical limits. In addition, I will also theoretically show that cells can amplify chemical gradients by secreting proteins that degrade these signaling molecules and that the secretion rate of these proteins matches its rough experimental estimate. 




Voditelji seminara IF-a: Nikša Krstulović i Osor Bari šić 



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Nikša Krstulović, PhD 
Research associate 

Institute of Physics 
Bijenicka 46 
HR-10000 Zagreb, Croatia 

Phone: 00385 1 4698 872 
00385 1 4698 851 
Fax: 00385 1 4698 889 

http://www.ifs.hr/ 
http://spectra.ifs.hr/ 
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