Heterozygous Mutations in Aromatic Amino Acid Synthesis Genes Trigger TOR Pathway Activation in Saccharomyces...

Area of Science:

• Cellular Biology
• Molecular Biology
• Biochemistry

Background:

• The Target of Rapamycin (TOR) pathway, comprising TORC1 and TORC2, regulates crucial cellular functions such as growth and autophagy in response to nutrient cues.
• While external nutrient regulation of TOR is well-studied, the effects of altered internal nutrient pools due to mutations in metabolic pathways remain largely unknown.

Purpose of the Study:

• To investigate the impact of heterozygous mutations in aromatic amino acid biosynthesis genes on TOR pathway activity.
• To analyze the downstream gene expression of TORC1 and assess autophagy induction as indicators of TORC1 and TORC2 signaling.

Main Methods:

• Analysis of gene expression downstream of TORC1 in yeast strains with heterozygous mutations in aromatic amino acid biosynthesis genes.
• Monitoring of autophagy induction as a readout for TORC1 and TORC2 activity.

Main Results:

• Heterozygous mutations in aromatic amino acid biosynthesis genes lead to significant alterations in TOR signaling.
• Differential gene expression patterns downstream of TORC1 were observed, indicating pathway modulation.
• Changes in autophagy induction suggest a functional impact on both TORC1 and TORC2.

Conclusions:

• Internal nutrient pool alterations, caused by mutations in metabolic pathways, can significantly impact TOR signaling.
• This study highlights a novel mechanism connecting amino acid biosynthesis to TOR pathway regulation.
• Findings provide insights into cellular adaptation to metabolic stress and its effect on fundamental processes like growth and autophagy.