Yeast mutants affected in viability upon starvation have a modified phospholipid composition

Area of Science:

• Molecular and Cellular Biology
• Yeast Genetics
• Cellular Morphology and Phospholipid Metabolism

Background:

• The RVS161 gene is crucial for yeast cell function, and its defects lead to specific cellular abnormalities.
• Understanding the genetic pathways involved in cellular processes is essential for deciphering complex biological mechanisms.

Purpose of the Study:

• To identify and characterize mutations that suppress defects in the yeast gene RVS161.
• To elucidate the biological pathway involving RVS161 and related genes through suppressor analysis.

Main Methods:

• Selection of suppressor mutations based on the suppression of rvs161 delta defects.
• Complementation analysis to group mutations into distinct complementation groups (SUR1-SUR4).
• Phenotypic characterization of mutant cell morphology in stationary phase.
• Analysis of phospholipid composition in wild-type and mutant yeast strains.

Main Results:

• Ten suppressor mutants were identified, falling into four complementation groups (SUR1-SUR4).
• All identified suppressor mutations also suppressed mutations in the RVS167 gene, suggesting involvement in a common pathway.
• Mutant cells exhibited abnormal morphologies, including dumbbell-like shapes (sur1-sur3) and multi-budded cells (sur4).
• Phospholipid analysis revealed decreased overall phospholipid amounts and altered relative contents of specific phospholipid classes in sur mutants.

Conclusions:

• The study identifies six genes (RVS161, RVS167, and four SUR genes) involved in the same biological pathway.
• Alterations in phospholipid metabolism are associated with the observed morphological defects in the suppressor mutants.
• These findings provide insights into the genetic regulation of cell morphology and phospholipid homeostasis in yeast.