Recording Signal Transduction Dynamics With Unprecedented Temporal Resolution
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July 23, 2012
Jonathan West, Research Associate, Miniaturisation Group, ISAS Dortmund
Abstract
The interface between the cell surface and its microenvironment represents the communication front for information processing, signaling and the emergent behaviour of the biological system. These events are initiated and cascade following the interaction of ligands with their host receptors. These interactions are of critical importance for understanding a tremendous spectrum of diseases and are prime targets for therapeutic intervention. Early signal transduction events include conformational and autocatalytic modifications, such as tyrosine auto-phosphorylation. These processes are rapid (<1 s), requiring the near-instantaneous delivery of biomolecules to the cell surface for synchronized stimulation. Mixing strategies, either macro- or microscopic, are prohibitively slow and therefore the sequence and mechanism of signal transduction processes remains unknown. To address this challenge we have developed a deterministic lateral displacement system for the deflection of a stream of single cells across the virtual interface between laminar flows and into the ligand-doped flow. Sub-millisecond switching times were obtained. The process is repeated for reaction quenching in readiness for off-chip analysis. Alternatively, the cell can be programmed with recombinant real-time fluorescent reporters for resolving the reaction kinetics thoughout the length of the microchannel. The system has been applied to the investigation of insulin-like growth factor receptor autophosphorylation transitions.
