Drosophila Melted modulates FOXO and TOR activity.

Area of Science:

• Cellular signaling pathways
• Metabolic regulation
• Drosophila melanogaster as a model organism

Background:

• The insulin/PI3K signaling pathway is crucial for regulating cellular functions, including tissue growth and metabolism.
• Dysregulation of this pathway is implicated in various metabolic disorders.
• Identifying novel modulators of this pathway can provide new insights into metabolic control.

Purpose of the Study:

• To identify and characterize novel components of the insulin/PI3K signaling pathway in Drosophila.
• To elucidate the function of the newly identified protein, Melted, in regulating this pathway.
• To investigate the physiological consequences of altered Melted activity on organismal metabolism.

Main Methods:

• Genetic screening in Drosophila to identify mutants affecting the insulin/PI3K pathway.
• Co-immunoprecipitation assays to determine protein-protein interactions.
• Analysis of target of rapamycin (TOR) activity and FOXO transcription factor activation.
• Measurement of fat content in wild-type and mutant Drosophila.

Main Results:

• Melted was identified as a novel modulator of the insulin/PI3K signaling pathway in Drosophila.
• Melted interacts with Tsc1 and FOXO, facilitating their recruitment to the cell membrane.
• Mutations in Melted lead to reduced TOR activity and increased FOXO activation.
• The melted mutant phenotype mimics nutrient deprivation, resulting in a significant reduction (40%) in fat content.

Conclusions:

• Melted plays a significant role in modulating insulin/PI3K signaling, impacting both growth and metabolism.
• The mechanism involves the interaction of Melted with Tsc1 and FOXO, influencing key pathway components.
• Melted represents a potential target for understanding and manipulating metabolic processes, particularly fat accumulation.