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Phosphorylated Gβ is a directional cue during yeast gradient tracking
Rashida Abdul-Ganiyu1, Leon A Venegas1, Xin Wang1
1Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
Science Signaling
|May 12, 2021
Summary
Yeast cells sense pheromone gradients to direct growth. Phosphorylated Gβ subunit dynamics, tracked by a novel biosensor, are crucial for this gradient sensing and mating efficiency.
Area of Science:
- Cell biology
- Biochemistry
- Genetics
Background:
- Budding yeast cells use pheromone gradients to find mating partners.
- A gradient-sensing model explains how yeast cells switch polarity sites.
- Phosphorylation of the Gβ subunit is hypothesized to be key in this process.
Purpose of the Study:
- To test predictions of a gradient-sensing model using a novel biosensor.
- To investigate the spatiotemporal dynamics of phosphorylated Gβ during mating.
- To determine the role of Gβ phosphorylation in yeast chemotropism.
Main Methods:
- Development of a biosensor for phosphorylated Gβ.
- Monitoring biosensor and reporter dynamics in mating yeast cells.
- Analysis of cells expressing a nonphosphorylatable Gβ mutant.
Main Results:
- The biosensor colocalized with Gβ and receptors, tracking from the default to the chemotropic site.
- Phosphorylated Gβ concentrated on the leading side of Gβ/receptor peaks.
- Nonphosphorylatable Gβ mutants showed impaired gradient tracking and mating.
Conclusions:
- Gradient-regulated Gβ phosphorylation is essential for yeast gradient sensing.
- Phosphorylated Gβ dynamics correlate with directional growth and mating partner orientation.
- Gβ phosphorylation plays a critical role in mating efficiency.
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