Open AccessLONP-1 and ATFS-1 sustain deleterious heteroplasmy by promoting mtDNA replication in dysfunctional mitochondria
Author(s) -
Qiyuan Yang,
Pengpeng Liu,
Nadine S. Anderson,
Tomer Shpilka,
Yunguang Du,
Nandhitha Uma Naresh,
Rui Li,
Lihua Julie Zhu,
Kevin Luk,
Josh Lavelle,
Rilee Zeinert,
Peter Chien,
Scot A. Wolfe,
Cole M. Haynes
Publication year - 2022
Publication title -
nature cell biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 11.38
H-Index - 369
eISSN - 1476-4679
pISSN - 1465-7392
DOI - 10.1038/s41556-021-00840-5
Subject(s) - heteroplasmy , mitochondrial dna , mitochondrion , biology , genetics , microbiology and biotechnology , gene
The accumulation of deleterious mitochondrial DNA (∆mtDNA) causes inherited mitochondrial diseases and ageing-associated decline in mitochondrial functions such as oxidative phosphorylation. Following mitochondrial perturbations, the bZIP protein ATFS-1 induces a transcriptional programme to restore mitochondrial function. Paradoxically, ATFS-1 is also required to maintain ∆mtDNAs in heteroplasmic worms. The mechanism by which ATFS-1 promotes ∆mtDNA accumulation relative to wild-type mtDNAs is unclear. Here we show that ATFS-1 accumulates in dysfunctional mitochondria. ATFS-1 is absent in healthy mitochondria owing to degradation by the mtDNA-bound protease LONP-1, which results in the nearly exclusive association between ATFS-1 and ∆mtDNAs in heteroplasmic worms. Moreover, we demonstrate that mitochondrial ATFS-1 promotes the binding of the mtDNA replicative polymerase (POLG) to ∆mtDNAs. Interestingly, inhibition of the mtDNA-bound protease LONP-1 increased ATFS-1 and POLG binding to wild-type mtDNAs. LONP-1 inhibition in Caenorhabditis elegans and human cybrid cells improved the heteroplasmy ratio and restored oxidative phosphorylation. Our findings suggest that ATFS-1 promotes mtDNA replication in dysfunctional mitochondria by promoting POLG-mtDNA binding, which is antagonized by LONP-1.