A SP1-Driven Translational-Proteostatic Checkpoint Modulates the Autophagy-Proteasome Network

A SP1-Driven Translational-Proteostatic Checkpoint Modulates the Autophagy-Proteasome Network | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article A SP1-Driven Translational-Proteostatic Checkpoint Modulates the Autophagy-Proteasome Network Aisha Ahmed, Junyu Chen, Amina Hamzatova, Yi Zhang, Xiaoxue Fu, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9285543/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Cellular homeostasis depends on the tightly coordinated transcription, translation, and proteostasis networks. How prolonged stress decouples these multi-dimensional networks to drive degenerative cell state drift remains unclear. Using chondrocytes, which endure long-term mechanical stress, as a model, we integrated human single-cell omics, spatial imaging, population genetics, and in vivo functional validation to map the spatiotemporal evolution of cell state instability. We identified SP1 as a key regulator maintaining network integrity, repressing eEF2K transcriptionally and binding it in the cytoplasm to enforce a dual-inhibition safety lock within a “translational-proteostatic checkpoint”. Prolonged stress disrupts the checkpoint, hyper phosphorylates eEF2, blocks translation elongation and depletes short-lived autophagy-proteasome and organelle effectors leading to autophagic flux failure, mitochondrial-lysosomal uncoupling, and organelle collapse. This dysfunction in clearance, rather than increased synthesis, drives abnormal SPP1 secretion, reprogramming the secretome and promote inflammatory chondrocyte phenotype. Mendelian randomization links this module and osteoarthritis risk, while targeted genetic and pharmacological interventions successfully restore proteostasis and reverse degenerative phenotypes in situ without requiring exogenous stem cells. Ultimately, by defining this translational-proteostatic checkpoint, our study elucidates a fundamental paradigm of how cells safeguard their state identity against chronic stress, providing a broad, stem-cell-independent conceptual and therapeutic framework to counteract cellular degeneration across diverse tissue. Biological sciences/Cell biology/Cell signalling/Checkpoint signalling Biological sciences/Cell biology/Mechanisms of disease transcriptional factor translational-proteostatic checkpoint cell homeostasis dual-failsafe autophagy-proteasome network osteoarthritis Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryVideoSP1andeEF2Kunder100nsdocking.mp4 Supplementary Video SP1 and eEF2K under 100 ns docking SupplementaryVideoeEF2andpeEF2under100nsdocking.mp4 Supplementary Video eEF2 and p-eEF2 under 100 ns docking SupplementaryVideoSP1proteintoeEF2KpromoterDNA.mp4 Supplementary Video SP1 protein to eEF2K promoter DNA SupplementaryFigures.docx Supplementary Figures Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9285543","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":616101120,"identity":"8cb5c306-ed63-4760-a753-849881d34b0f","order_by":0,"name":"Aisha 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