@article {69865, title = {FilaBuster: A Strategy for Rapid, Specific, and Spatiotemporally Controlled Intermediate Filament Disassembly}, journal = {bioRxiv}, year = {2025}, month = {2025 Apr 20}, abstract = {

Intermediate filaments (IFs) play key roles in cellular mechanics, signaling, and organization, but tools for their rapid, selective disassembly remain limited. Here, we introduce FilaBuster, a photochemical approach for efficient and spatiotemporally controlled IF disassembly in living cells. FilaBuster uses a three-step strategy: (1) targeting HaloTag to IFs, (2) labeling with a covalent photosensitizer ligand, and (3) light-induced generation of localized reactive oxygen species to trigger filament disassembly. This modular strategy applies broadly across IF subtypes{\textemdash}including vimentin, GFAP, desmin, peripherin, and keratin 18{\textemdash}and is compatible with diverse dyes and imaging platforms. Using vimentin IFs as a model system, we establish a baseline implementation in which vimentin-HaloTag labeled with a photosensitizer HaloTag ligand triggers rapid and specific IF disassembly upon light activation. We then refine this approach by (i) expanding targeting strategies to include a vimentin nanobody-HaloTag fusion, (ii) broadening the range of effective photosensitizers, and (iii) optimizing irradiation parameters to enable precise spatial control over filament disassembly. Together, these findings position FilaBuster as a robust platform for acute, selective, and spatiotemporally precise disassembly of IF networks, enabling new investigations into their structural and functional roles in cell physiology and disease.

}, doi = {10.1101/2025.04.20.649718}, url = {https://www.biorxiv.org/content/early/2025/04/21/2025.04.20.649718}, author = {Moore, Andrew S. and Krug, Tommy and Hansen, Simon B. and Ludlow, Alexander V. and Grimm, Jonathan B. and Ayala, Anthony X. and Plutkis, Sarah E. and Wang, Nan and Goldman, Robert D. and Medalia, Ohad and Lavis, Luke D. and Weitz, David A. and Lippincott-Schwartz, Jennifer} } @article {70179, title = {Secretome translation shaped by lysosomes and lunapark-marked ER junctions.}, journal = {Nature}, year = {2025}, month = {2025 Nov 05}, abstract = {

The endoplasmic reticulum (ER) is a highly interconnected membrane network that serves as a central site for protein synthesis and maturation. A crucial subset of ER-associated transcripts, termed secretome mRNAs, encode secretory, lumenal and integral membrane proteins, representing nearly one-third of human protein-coding genes. Unlike cytosolic mRNAs, secretome mRNAs undergo co-translational translocation, and thus require precise coordination between translation and protein insertion. Disruption of this process, such as through altered elongation rates, activates stress response pathways that impede cellular growth, raising the question of whether secretome translation is spatially organized to ensure fidelity. Here, using live-cell single-molecule imaging, we demonstrate that secretome mRNA translation is preferentially localized to ER junctions that are enriched with the structural protein lunapark and in close proximity to lysosomes. Lunapark depletion reduced ribosome density and translation efficiency of secretome mRNAs near lysosomes, an effect that was dependent on eIF2-mediated initiation and was reversed by the integrated stress response inhibitor ISRIB. Lysosome-associated translation was further modulated by nutrient status: amino acid deprivation enhanced lysosome-proximal\ translation, whereas lysosomal pH neutralization suppressed it. These findings identify a mechanism by which ER junctional proteins and lysosomal activity cooperatively pattern secretome mRNA translation, linking ER architecture and nutrient sensing to the production of secretory and membrane proteins.

bioRxiv preprint:\ https://doi.org/10.1101/2024.11.21.624573

}, issn = {1476-4687}, doi = {10.1038/s41586-025-09718-0}, url = {https://doi.org/10.1038/s41586-025-09718-0}, author = {Choi, Heejun and Liao, Ya-Cheng and Yoon, Young J and Grimm, Jonathan and Wang, Nan and Lavis, Luke D and Singer, Robert H and Lippincott-Schwartz, Jennifer} }