MFN2 interacts with phosphorylated AMPK to mediate mitophagy in MCF-7 cells

Area of Science:

• Cell Biology
• Mitochondrial Dynamics
• Autophagy

Background:

• Mitofusin 2 (MFN2) is implicated in mitophagy, but its precise mechanism remains unclear.
• Understanding MFN2's role is crucial for deciphering mitochondrial quality control pathways.

Purpose of the Study:

• To elucidate the mechanism by which MFN2 mediates mitophagy.
• To investigate the interaction between MFN2 and AMP-activated protein kinase (AMPK) in mitophagy.

Main Methods:

• Utilized MCF-7 cells with MFN2 overexpression and knockdown.
• Employed fluorescence imaging, subcellular fractionation, Förster resonance energy transfer (FRET), site-directed mutagenesis, and co-immunoprecipitation.
• Investigated the effects of Leflunomide (Lef), Compound C, and Acadesine (AICAR) on mitophagy.

Main Results:

• MFN2 upregulation drives mitophagy; MFN2 knockdown inhibits Lef-induced mitophagy.
• MFN2 promotes AMPK phosphorylation at Thr172 and its mitochondrial translocation.
• A phosphorylation-dependent MFN2-AMPK complex is formed, which is essential for mitophagy.

Conclusions:

• MFN2 recruits Thr172-phosphorylated AMPK to mitochondria via a phosphorylation-dependent MFN2-AMPK complex.
• This interaction is critical for efficient mitophagy and mitochondrial degradation.
• MFN2 acts as a key mediator in the mitophagy pathway.