PPTC7 antagonizes mitophagy by promoting BNIP3 and NIX degradation via SCF(FBXL4)

Nguyen-Dien, GT; Townsend, B; Kulkarni, PG; Kozul, KL; Ooi, SS; Eldershaw, DN; Weeratunga, S; Liu, M; Jones, MJ; Millard, SS; Ng, DC; Pagano, M; Bonfim-Melo, A; Schneider, T; Komander, D; Lazarou, M; Collins, BM; Pagan, JK

Author(s): Nguyen-Dien, GT; Townsend, B; Kulkarni, PG; Kozul, KL; Ooi, SS; Eldershaw, DN; Weeratunga, S; Liu, M; Jones, MJ; Millard, SS; Ng, DC; Pagano, M; Bonfim-Melo, A; Schneider, T; Komander, D; Lazarou, M; Collins, BM; Pagan, JK;
Details: Publication Year 2024-07-11,Volume 25,Issue #8,Page 3324-3347
Journal Title: EMBO Reports
Abstract: Mitophagy must be carefully regulated to ensure that cells maintain appropriate numbers of functional mitochondria. The SCF(FBXL4) ubiquitin ligase complex suppresses mitophagy by controlling the degradation of BNIP3 and NIX mitophagy receptors, and FBXL4 mutations result in mitochondrial disease as a consequence of elevated mitophagy. Here, we reveal that the mitochondrial phosphatase PPTC7 is an essential cofactor for SCF(FBXL4)-mediated destruction of BNIP3 and NIX, suppressing both steady-state and induced mitophagy. Disruption of the phosphatase activity of PPTC7 does not influence BNIP3 and NIX turnover. Rather, a pool of PPTC7 on the mitochondrial outer membrane acts as an adaptor linking BNIP3 and NIX to FBXL4, facilitating the turnover of these mitophagy receptors. PPTC7 accumulates on the outer mitochondrial membrane in response to mitophagy induction or the absence of FBXL4, suggesting a homoeostatic feedback mechanism that attenuates high levels of mitophagy. We mapped critical residues required for PPTC7-BNIP3/NIX and PPTC7-FBXL4 interactions and their disruption interferes with both BNIP3/NIX degradation and mitophagy suppression. Collectively, these findings delineate a complex regulatory mechanism that restricts BNIP3/NIX-induced mitophagy.
Publisher: EMBO Press
Keywords: Bnip3; Fbxl4; Mitophagy; Nix; Pptc7
Research Division(s): Ubiquitin Signalling
PubMed ID: 38992176
Publisher's Version: https://doi.org/10.1038/s44319-024-00181-y
Open Access at Publisher's Site: https://doi.org/10.1038/s44319-024-00181-y
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2024-07-26 09:22:59

Last Modified: 2024-08-14 11:33:35