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BP: Fachverband Biologische Physik

BP 29: Posters: Regulation

BP 29.5: Poster

Donnerstag, 29. März 2012, 17:30–19:30, Poster A

Cell polarisation’s impact on local and global calcium signals during T-cell activation — •Martin Peglow and Heiko Rieger — Universität des Saarlandes

A crucial step for the successful T-cell activation is the stimulation of calcium (Ca²⁺) entry across the plasma membrane through the so called Ca²⁺ release-activated Ca²⁺ (CRAC) channel. Recently Quintana et. al (The EMBO Journal (2011) 30, 3895 - 3912) have shown, that cell polarisation (the rearrangement of several cell organelles) is a very important step in T-cell- and CRAC-channel-activation. With our model we want to verify if different relativ positions between CRAC-channels, mitochondria and plasma membrane calcium-ATPases (PMCA)-pumps are sufficient to explain the different Ca²⁺ -signals in T-cells. And indeed we can shown, that mitochondria near to the CRAC-channel lead to a higher global Ca²⁺-concentration and a lower Ca²⁺ microdomain near the CRAC-channel. A nice result is, that an accumulation of PMCA-pumps near the CRAC-channel is essential for high global Ca²⁺-signals and so for T-cell activation and that in contrast a uniform distribution of PMCA-pumps in the PM lead to lower cytosolic Ca²⁺ -signals. This prediction should be investigated in some new experiments.