Cell Stress & Chaperones最新文献

Post-translational protein modifications (PTMs) are fundamentally important in regulating protein function across species. One such PTM, referred to as protein AMPylation, is increasingly recognized to finetune ER stress signaling in metazoans. Protein AMPylation in the ER is catalyzed by conserved fic-domain containing enzymes (fic AMPylases), including FICD (Homo sapiens) and FIC-1 (Caenorhabditis elegans). However, it remains unclear whether enhanced fic AMPylase-mediated protein AMPylation promotes a conserved cellular response. In this study, we determined the transcriptomic consequences of increased fic AMPylase-mediated protein AMPylation in mouse fibroblasts and young adult nematodes. We find that in C. elegans, FIC-1(E274G) over-expression (OE) triggers a unique transcriptional signature, leading to the marked upregulation of pathways involved in cellular stress signaling. We further show that FIC-1(E274G) OE upregulates genes involved in antibacterial innate immune responses and identify a potentially co-regulated gene cluster sensitive to changes in AMPylation levels. Intriguingly, we observe a similar transcriptomic signature in mouse fibroblasts in response to FICD(E234G) OE. A cross-species comparison of the transcriptomes of nematodes, yeast, and mouse fibroblasts enduring increased fic AMPylase-mediated protein AMPylation revealed a conserved transcriptional core response to enhanced AMPylation. Collectively, this study defines a conserved cellular stress response to enhanced fic AMPylase-mediated protein AMPylation.

Dr. Len Neckers played a pioneering role in establishing that HSP90 is regulated by post-translational modifications (PTMs), fundamentally reshaping how molecular chaperones are understood. This insight laid the foundation for what has become known as the "chaperone code", the concept that coordinated PTM patterns act as regulatory signals governing chaperone function, interactions, and stress responsiveness. In this short perspective, I reflect on how Len's early work seeded this conceptual shift and how subsequent advances have revealed that PTMs not only fine-tune canonical chaperone activities but can also enable chaperones to adopt non-canonical functional states under specific stress conditions. These developments have expanded the landscape of chaperone biology, illustrating how chemical encoding can diversify chaperone behavior and reconfigure protein networks. Together, they highlight the enduring impact of Len's contributions and the importance of embracing complexity in understanding chaperone function.

The 13th International Symposium on Heat Shock Proteins in Biology, Medicine and the Environment, organized by the Cell Stress Society International (CSSI), was held in October 2025 in Syracuse, NY, and brought together investigators spanning basic,translational, and clinical stress biology. The meeting highlighted the continued evolution of the heat shock response from a canonical transcriptional program to a complex, multi-layered network integrating transcriptional condensates, posttranslational regulation of chaperones, spatial organization, and system-level stress adaptation. Scientific sessions showcased advances in stress-induced transcription and genome control, the expanding Hsp90/Hsp70 "chaperone code," proteostasis and protein quality control, mitochondrial chaperones and metabolic regulation, cancer-immune interfaces, host-pathogen interactions, and the roles of chaperones in aging and neurodegenerative disease. Particular emphasis was placed on emerging therapeutic and diagnostic strategies, including isoform-specific chaperone inhibitors, co-chaperone targeting, theranostic approaches, and clinical-stage candidates. Systems-level analyses of stress resilience, extracellular chaperone signaling, and organismal adaptation further underscored the breadth of stress biology across scales. The symposium also honored the legacy of Dr. Len Neckers, whose pioneering contributions to Hsp90 biology shaped the field, and recognized outstanding scientific achievements through CSSI awards and fellowships. Collectively, the work presented reflects a field that continues to deepen mechanistic understanding while advancing toward precision-based therapeutic and diagnostic applications. This meeting report summarizes these developments and highlights future directions for stress biology research.

Cells counteract proteotoxic conditions by launching transcriptional stress responses. While synthesis of Heat shock proteins (HSPs) upon acute stress is well-characterized, how distinct proteotoxic conditions reshape the transcriptome remains poorly understood. Here, we analyse polyA+ RNA expression under heat shock, HSP90 inhibition, and polyglutamine (polyQ) aggregation. We find fundamentally distinct transcriptional responses to proteotoxic stressors, and a systemic deficiency of mice under chronic stress to launch acute responses. While heat shock and HSP90 inhibition induce chaperones, polyQ aggregation increases expression of RNAs linked to transcription repression, chromatin remodeling, and autophagy. Analysing wildtype and Huntington's Disease (HD) mice reveals tissue-specific transcriptional adaptations to polyQ, including repressed cell-type specific functions and altered energy metabolism. Despite profound reprogramming, remarkably few genes exhibit consistently increased (Acy3, Abhd1, Tmc3) or decreased (Fos) RNA levels across HD brain regions. These results emphasize cellular background in disease manifestation, and support energy metabolism and detoxifying enzymes as therapeutic targets in late-stage HD. Moreover, the systemic deficiency of chronically stressed mice to launch responses challenges strategies that rely on induced transcription. Altogether, we characterize transcription signatures to proteotoxic stresses, identify key trans-activators driving proteotoxic stress responses, provide an interactive gene-by-gene viewer of global changes, and delineate tissue-specific transcription programs in HD mice.