Dominant-negative Dmp53 extends life span through the dTOR pathway in D. melanogaster

Area of Science:

• Aging research
• Molecular biology
• Genetics

Background:

• The tumor suppressor p53 has an ortholog in Drosophila, Dmp53.
• Dominant-negative (DN) Dmp53 expression extends fly lifespan, particularly under calorie restriction (CR).
• DN-Dmp53 reduces Drosophila insulin-like peptide 2 (dILP2) mRNA and insulin/insulin-like growth factor-signaling (IIS) activity.

Purpose of the Study:

• To elucidate the mechanisms by which DN-Dmp53 extends longevity.
• To determine if IIS modulation is crucial for Dmp53-mediated lifespan regulation.
• To investigate the interplay between Dmp53, IIS, and dTor signaling in lifespan extension.

Main Methods:

• Expression of dominant-negative Dmp53 in Drosophila melanogaster.
• Manipulation of dILP2 and dFoxO (IIS pathway components) levels.
• Assessment of lifespan extension in genetically modified flies.
• Analysis of Thor/4E-BP (dTor pathway component) function.

Main Results:

• Lifespan extension by DN-Dmp53 requires reduced Dmp53 activity and is abolished by dILP2 overexpression.
• DN-Dmp53-mediated lifespan extension is linked to IIS, as it does not further extend lifespan in dFoxO overexpressing flies.
• Reduction of dFoxO levels does not impact DN-Dmp53-dependent longevity.
• DN-Dmp53 fails to extend lifespan in flies lacking Thor/4E-BP, a dTor signaling target.

Conclusions:

• Dmp53 influences lifespan through mechanisms involving both IIS and dTor signaling pathways.
• Reduced Dmp53 activity extends lifespan, potentially by modulating IIS.
• The dTor pathway is essential for DN-Dmp53-mediated lifespan extension in Drosophila.