Exploring carbon source related localization and phosphorylation in the Snf1/Mig1 network using population and single...

Area of Science:

• Cellular biology
• Molecular and Systems Biology
• Metabolic regulation

Background:

• The AMP-activated protein kinase (AMPK) and SNF1 pathway are crucial for maintaining energy homeostasis in eukaryotic cells.
• In Saccharomyces cerevisiae (yeast), Snf1 kinase activation via phosphorylation upon glucose depletion is essential but insufficient for glucose de-repression.
• This suggests additional glucose-dependent regulatory mechanisms govern the pathway's function.

Purpose of the Study:

• To investigate the spatial dynamics of Snf1 kinase and its relationship with the Mig1 repressor.
• To elucidate the role of Snf1 localization in response to varying hexose sugar concentrations and carbon sources.
• To understand the complex regulation of the Snf1 pathway in cellular energy balance.

Main Methods:

• Utilized fluorescence recovery after photobleaching (FRAP) to analyze Snf1 protein dynamics.
• Employed non-linear mixed effects modeling to quantify kinetic parameters of Snf1 localization.
• Studied the interplay between Snf1 phosphorylation, Mig1 localization, and hexose sugar availability.

Main Results:

• Snf1 inactivation influences the nuclear localization of its target, Mig1.
• The kinetics of Snf1 nuclear import are modulated by the presence of non-fermentable carbon sources.
• Demonstrated a correlation between Snf1 localization dynamics and its phosphorylation state.

Conclusions:

• Snf1 localization is a critical regulatory layer in the glucose de-repression process, complementing its phosphorylation status.
• The study provides novel insights into the intricate regulation of the Snf1 pathway, essential for cellular adaptation to environmental cues.
• Findings advance the understanding of glucose homeostasis and highlight the importance of Snf1 spatial dynamics in regulating downstream targets.