FBXL4 suppresses mitophagy by restricting the accumulation of NIX and BNIP3 mitophagy receptors

Nguyen-Dien, GT; Kozul, KL; Cui, Y; Townsend, B; Kulkarni, PG; Ooi, SS; Marzio, A; Carrodus, N; Zuryn, S; Pagano, M; Parton, RG; Lazarou, M; Millard, SS; Taylor, RW; Collins, BM; Jones, MJ; Pagan, JK

Author(s): Nguyen-Dien, GT; Kozul, KL; Cui, Y; Townsend, B; Kulkarni, PG; Ooi, SS; Marzio, A; Carrodus, N; Zuryn, S; Pagano, M; Parton, RG; Lazarou, M; Millard, SS; Taylor, RW; Collins, BM; Jones, MJ; Pagan, JK;
Details: Publication Year 2023-05-10,Volume 42,Issue #13,Page e112767
Journal Title: EMBO Journal
Abstract: To maintain both mitochondrial quality and quantity, cells selectively remove damaged or excessive mitochondria through mitophagy, which is a specialised form of autophagy. Mitophagy is induced in response to diverse conditions, including hypoxia, cellular differentiation and mitochondrial damage. However, the mechanisms that govern the removal of specific dysfunctional mitochondria under steady-state conditions to fine-tune mitochondrial content are not well understood. Here, we report that SCF(FBXL4) , an SKP1/CUL1/F-box protein ubiquitin ligase complex, localises to the mitochondrial outer membrane in unstressed cells and mediates the constitutive ubiquitylation and degradation of the mitophagy receptors NIX and BNIP3 to suppress basal levels of mitophagy. We demonstrate that the pathogenic variants of FBXL4 that cause encephalopathic mtDNA depletion syndrome (MTDPS13) do not efficiently interact with the core SCF ubiquitin ligase machinery or mediate the degradation of NIX and BNIP3. Thus, we reveal a molecular mechanism whereby FBXL4 actively suppresses mitophagy by preventing NIX and BNIP3 accumulation. We propose that the dysregulation of NIX and BNIP3 turnover causes excessive basal mitophagy in FBXL4-associated mtDNA depletion syndrome.
Publisher: Wiley
Keywords: Bnip3; Fbxl4; Nix/bnip3l; mitochondria; mitophagy
Research Division(s): Ubiquitin Signalling
PubMed ID: 37161784
Publisher's Version: https://doi.org/10.15252/embj.2022112767
Open Access at Publisher's Site: https://doi.org/10.15252/embj.202211276
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2023-06-26 09:53:33

Last Modified: 2023-07-12 08:08:22