bims-tofagi 2026-08-30 papers

Issue of 2026–08–30
two papers selected by
Michele Frison, University of Cambridge

Autophagy. 2026 Aug 28.

A New agent in the matrix: PINK1's expanded role in mitochondrial surveillance and Regulation.

Ian Collinson, Robin A Corey, Adam G Grieve.

The identification of pathogenic autosomal recessive mutations in the gene encoding the PINK1 kinase provided early evidence linking mitochondrial dysfunction to neurodegeneration - in this case Parkinson's Disease. PINK1 has since become synonymous with mitophagy, with the prevailing model proposing two alternative fates. The first being partial import - inner-membrane penetration of its transmembrane domain (TMD) - followed by PARL-mediated cleavage and degradation. This happens in healthy mitochondria with a high membrane potential (ΔΨ) across the inner-membrane - required for passage of proteins into or across the inner-membrane. The second being surface stabilization, Parkin activation and initiation of mitophagy upon membrane depolarization. But what if PINK1 acts in active mitochondria as well? Our recent work identifies a third fate - matrix entry! The findings expand the biology of PINK1 beyond mitochondrial surveillance for quality control alone. They suggest an additional mitophagy-independent regulatory role within the matrix, which turns out to be governed by the unusual properties of its TMD for the conferral of a decisive conformational switch.

Keywords: Mitochondria; PARL; PINK1; Parkinson’s disease; transmembrane

DOI: https://doi.org/10.1080/15548627.2026.2726091

Nat Commun. 2026 Jul 24. pii: 9041. [Epub ahead of print]17(1):

Mitophagy mitigates mitochondrial DNA-induced activation of cGAS-STING in autoimmune thyroiditis.

Autoimmune thyroiditis arises from disrupted homeostasis of thyroid follicular epithelial cells and coordinated immune cell activation within the microenvironment. However, its pathogenesis is not fully understood. Here, we identify a mitochondrial (mt) DNA-cGAS-STING inflammatory axis as a driver of autoimmune thyroiditis in mice. By contrast, ubiquitin-dependent mitophagy mediated by PINK1 and Parkin was found to protect mice from disease. Mechanistically, mitochondrial dysfunction elevates mitochondrial reactive oxygen species levels, activating the ATM-CHK2 DNA damage response pathway, which in turn phosphorylates the autophagy adapter TAX1BP1 at Ser722. This modification promotes the recruitment of mitochondria to autophagosomes, thereby facilitating mitophagy. Impairing the ATM-CHK2-TAX1BP1 mitophagy pathway causes mtDNA leakage into the cytosol and triggers cGAS-STING-dependent inflammation. Notably, pharmacological inhibition of STING with C176 effectively slows autoimmune thyroiditis progression. Together, these findings define an mtDNA-driven pathogenic mechanism in autoimmune thyroiditis and identify STING as a potential therapeutic target.

DOI: https://doi.org/10.1038/s41467-026-76047-9