University of Minnesota
School of Physics & Astronomy

Biophysics Seminar

Tuesday, January 27th 2015
2:30 pm:
Biophysics Seminar in 210 Physics
Speaker: Elias Puchner, University of Minnesota
Subject: Clustering of a cellular signaling complex provides a mesoscopic hierarchy for tuning pathway gain

Cells have the remarkable ability to accurately sense chemical gradients over a wide range of concentrations. The process of chemotaxis and chemotropism has been extensively studied in the past and it has been shown that adaptation is a crucial feature of the underlying signaling networks. Although many signaling proteins responsible for gradient sensing have been identified, it is unclear whether or how their spatial distribution can modulate pathway activity. Here, we show that spatial clustering of a signaling complex presents an additional regulatory layer that actively tunes pathway gain. We demonstrate that clustering of the signaling complex itself activates the pathway bypassing receptor activation and that the degree of clustering correlates with the adaptive output. Furthermore we identify a negative feedback, which acts on the degree of clustering and which allows adaptation to the input stimulus. Our results may present a general principle of how cells use spatial re-distribution of its signaling proteins as an additional regulatory layer to tune pathway activity.

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