Autophagy is the process cells use to degrade and recycle unnecessary or dysfunctional cellular components. When mitochondria are degraded, the process is called mitophagy. A complex autophagy machinery, including ULK1 and FIP200, is necessary to guide this process. During the initiation of mitophagy, the ULK1 kinase complex plays a major role by engaging mitophagy receptors via its FIP200 subunit. Whether FIP200 is also relevant in later stages of mitophagy and how its regulation occurs remained unclear.
A joint research study headed by SFB 1381 PIs Claudine Kraft and Laura Gámez-Díaz (both B10) in collaboration with SFB PI Chris Meisinger (A06) demonstrates that the regulation of FIP200 is crucial for the progression of mitophagy. FIP200 undergoes phosphorylation and dephosphorylation, controlling the early and late stages of mitophagy. These phosphorylation events also influence FIP200’s interaction with ATG16L1, another key component in the later stages of mitophagy. Overall, the results indicate that FIP200 is relevant in all stages of mitophagy, not just in the beginning as previously thought.
The original publication was published in the Journal of Molecular Biology and can be found here.
Illustration: Claudine Kraft
