Cold Temperature Induces the Reprogramming of Proteolytic Pathways in Yeast

Area of Science:

• Cellular Biology
• Stress Response

Background:

• The proteasome-ubiquitin system is crucial for temperature stress response.
• The specific dynamics of the ubiquitylome during cold stress remain largely uncharacterized.

Purpose of the Study:

• To investigate the quantitative ubiquitylome changes during cold response.
• To elucidate the role of the proteasome in plasma membrane protein regulation under cold stress.

Main Methods:

• Quantitative proteomic analysis of ubiquitylomes in a proteasome mutant and reference strain.
• Assessment of plasma membrane protein internalization and degradation at varying temperatures.
• In vivo analysis of proteasome interactions with ubiquitylated proteins.

Main Results:

• Cold exposure significantly alters ubiquitylation patterns, particularly affecting Rsp5-regulated plasma membrane proteins.
• The proteasome becomes essential for plasma membrane protein internalization and degradation at low temperatures, unlike at 30°C.
• Proteasomes exhibit an enhanced interaction with lysine 63-polyubiquitylated proteins during cold conditions.

Conclusions:

• Cold stress induces a cellular reprogramming of proteasome function.
• The proteasome gains a significant role in the endocytic-vacuolar pathway during cold response.