bims-nocaut 2025-08-31 papers

Issue of 2025–08–31
three papers selected by
Quentin Frenger, University of Strasbourg

Autophagy. 2025 Aug 28. 1-15

Deacetylation of ATG16L1 is required for LC3-associated lysosomal microautophagy.

Qian Wang, Wei Wan, Hongtao Zhang, Tianhua Zhou, Han-Ming Shen, Pingtong Huang, Wei Liu.

Microautophagy is a selective cellular process in which endolysosomes directly engulf cytoplasmic cargo through membrane invagination. The regulatory mechanisms governing microautophagy remain poorly understood. Here, we identified the deacetylation of ATG16L1 as a critical regulator of LC3-associated lysosomal microautophagy. We demonstrate that ATG16L1 acetylation is dynamically controlled by the acetyltransferase KAT2B and the deacetylase HDAC3. Under lysosomal osmotic stress or glucose deprivation, HDAC3-mediated deacetylation of ATG16L1 within its WD40 domain promotes its interaction with V-ATPase, facilitating ATG16L1 recruitment to lysosomal membranes. While dispensable for macroautophagy, this post-translational modification is essential for LC3 lipidation on lysosomes and enables lysosomal recovery, including the restoration of lysosomal size and degradative capacity following stress. Our results reveal a key role for ATG16L1 deacetylation in driving LC3-associated microautophagy to maintain lysosomal homeostasis.

Keywords: ATG16L1; Acetylation; LC3 lipidation; LC3-associated microautophagy; V-ATPase; lysosome

DOI: https://doi.org/10.1080/15548627.2025.2551669

Cell Insight. 2025 Oct;4(5): 100266

Beyond interferons: Non-canonical roles of MITA/STING.

Liting Zhang, Chuchu Zhang, Junjie Zhang.

Mediator of IRF3 activation (MITA)/Stimulator of Interferon Genes (STING) (also known as MPYS/ERIS) is a crucial adaptor protein for initiating antiviral innate immune responses to intracellular DNA and DNA viruses. MITA binds cGAMP, a second messenger synthesized by cGAS in response to intracellular DNA, culminating in the induction of type I interferons (IFNs), inflammatory cytokines, and interferon-stimulated genes (ISGs). While the canonical IFN-dependent MITA signaling has been extensively studied, recent research has unveiled a growing repertoire of IFN-independent functions of MITA in various physiological processes and pathological conditions. These non-canonical roles of MITA are increasingly recognized for their involvement in critical processes such as antiviral activity, senescence, autophagy, metabolism, lysosomal biogenesis, and the development of neurological disorders. In this review, we summarize the latest advances in understanding MITA's non-canonical functions and provide insights into key scientific questions that remain to be addressed. Deciphering how MITA is involved in these complex physiological and pathological processes will not only deepen our understanding of MITA signaling, but may also offer new therapeutic targets for treating related diseases.

DOI: https://doi.org/10.1016/j.cellin.2025.100266

Nat Cell Biol. 2025 Aug 25.

CHIP protects lysosomes from CLN4 mutant-induced membrane damage.

Juhyung Lee, Natalie Chin, Jizhong Zou, Wan Nur Atiqah Binti Mazli, Michal Jarnik, Layla Saidi, Yue Xu, Eutteum Jeong, Jessica Suh, John Replogle, Michael E Ward, Juan S Bonifacino, Wei Zheng, Ling Hao, Yihong Ye.

Understanding how cells mitigate lysosomal damage is critical for unravelling pathogenic mechanisms of lysosome-related diseases. Here we generate and characterize induced pluripotent stem cell (iPSC)-derived neurons (i3Neuron) bearing ceroid lipofuscinosis neuronal 4 (CLN4)-linked DNAJC5 mutations, which revealed extensive lysosomal abnormality in mutant neurons. In vitro membrane-damaging experiments establish lysosomal damages caused by lysosome-associated CLN4 mutant aggregates, as a critical pathogenic linchpin in CLN4-associated neurodegeneration. Intriguingly, in non-neuronal cells, a ubiquitin-dependent microautophagy mechanism downregulates CLN4 aggregates to counteract CLN4-associated lysotoxicity. Genome-wide CRISPR screens identify the ubiquitin ligase carboxyl terminus of Hsc70-interacting protein (CHIP) as a central microautophagy regulator that confers ubiquitin-dependent lysosome protection. Importantly, CHIP's lysosome protection function is transferrable: ectopic CHIP improves lysosomal function in CLN4 i3Neurons and effectively alleviates lipofuscin accumulation and cell death in a Drosophila CLN4 disease model. Our study establishes CHIP-mediated microautophagy as a key organelle guardian that preserves lysosome integrity, offering new insights into therapeutic development for lysosome-related neurodegenerative diseases.

DOI: https://doi.org/10.1038/s41556-025-01738-2