Temporal and Spatial Properties of a Yeast Multi-Cellular Amplification System Based on Signal Molecule Diffusion

Abstract

We report on the spatial and temporal signaling properties of a yeast pheromone-based cell communication and amplifier system. It utilizes the Saccharomyces cerevisiae mating response pathway and relies on diffusion of the pheromone α–factor as key signaling molecule between two cell types. One cell type represents the α–factor secreting sensor part and the other the reporter part emitting fluorescence upon activation. Although multi-cellular signaling systems promise higher specificity and modularity, the complex interaction of the cells makes prediction of sensor performance difficult. To test the maximum distance and response time between sensor and reporter cells, the two cell types were spatially separated in defined compartments of agarose hydrogel (5 × 5 mm) and reconnected by diffusion of the yeast pheromone. Different ratios of sensor to reporter cells were tested to evaluate the minimum amount of sensor cells required for signal transduction. Even the smallest ratio, one α–factor-secreting cell to twenty reporter cells, generated a distinct fluorescence signal. When using a 1:1 ratio, the secreted pheromone induced fluorescence in a distance of up to four millimeters after six hours. We conclude from both our experimental results and a mathematical diffusion model that in our approach: (1) the maximum dimension of separated compartments should not exceed five millimeters in gradient direction; and (2) the time-limiting step is not diffusion of the signaling molecule but production of the reporter protein.

The Saccharomyces cerevisiae pheromone-response is a metabolically active stationary phase for bio-production

“…The S. cerevisiae mating system has become a cornerstone of eukaryotic synthetic biology ( Furukawa and Hohmann, 2013 ). The pheromone communication system has been utilised for synthetic quorum sensing ( Williams et al, 2015a , Williams et al, 2013 ), signal amplification ( Groß et al, 2011 ), intercellular and interspecies communication ( Hennig et al, 2015 , Jahn et al, 2013 ), and biological computation ( Regot et al, 2011 ). Furthermore, the depth of knowledge surrounding the mitogen activated protein kinase (MAPK) signal transduction machinery has enabled the construction and fine-tuning of a multitude of synthetic regulatory circuits ( Bashor et al, 2008 , Ingolia and Murray, 2007 , O’Shaughnessy et al, 2011 , Tanaka and Yi, 2009 ).…”

New approaches in bioprocess‐control: Consortium guidance by synthetic cell‐cell communication based on fungal pheromones

“…in hydrogel matrices. As the pheromones diffuse across the compartment boundary, artificial patterns were created, and competition of both cell types for essential nutrients was prevented .…”

“…in hydrogel matrices. As the pheromones diffuse across the compartment boundary, artificial patterns were created, and competition of both cell types for essential nutrients was prevented [63]. This approach might serve as a blueprint for the development of cellular consortia performing complex tasks ( Fig.…”

Artificial cell-cell communication as an emerging tool in synthetic biology applications

“…Synthetic pattern formation has recently also been shown in a fungal system [ 138 ]. Yeast sender cells secreting the α-factor pheromone and responding receiver cells were immobilized in separate compartments within a hydrogel matrix.…”