panoramaProteomicsDietmar KültzBotryllus Schlosserihttps://panoramaweb.org/bosch02kl.urldkueltz@ucdavis.eduUniversity of California, DavisPanoramaPublicThe colonial ascidian <i>Boytryllus schlosseri</i> is an invasive marine chordate that thrives under conditions of anthropogenic climate change. We show that the B. schlosseri expressed proteome contains unusually high levels of proteins that are adducted with 4-hydroxy-2-nonenal (HNE). HNE represents a prominent posttranslational modification resulting from oxidative stress. Although numerous studies have assessed oxidative stress in marine organisms HNE protein modification has not previously been determined in any marine species. LC/MS proteomics was used to identify 1052 HNE adducted proteins in B. schlosseri field and laboratory populations. Adducted amino acid residues were ascertained for 1849 modified sites, of which 1195 had a maximum amino acid localization score. Most HNE modifications were at less reactive lysines (rather than more reactive cysteines). HNE prevelance on most sites was high. These observations suggest that B. schlosseri experiences and tolerates high intracellular reactive oxygen species levels, resulting in substantial lipid peroxidation. HNE adducted B. schlosseri proteins show enrichment in mitochondrial, proteostasis, and cytoskeletal functions. Based on these results we propose that redox signaling contributes to regulating energy metabolism, the blastogenic cycle, oxidative burst defenses, and cytoskeleton dynamics during B. schlosseri development and physiology. A DIA assay library was constructed to quantify HNE adduction at 72 sites across 60 proteins that represent a holistic network of functionally discernable oxidative stress bioindicators. We conclude that the vast amount of HNE protein adduction in this circumpolar tunicate is indicative of high oxidative stress tolerance contributing to its range expansion into diverse environments.<h4>New & noteworthy</h4>Oxidative stress results from environmental challenges that increase in frequency and severity during the Anthropocene. Oxygen radical attack causes lipid peroxidation leading to HNE production. Proteome-wide HNE adduction is highly prevalent in <i>Botryllus schlosseri</i> , a widely distributed, highly invasive, and economically important biofouling ascidian and the first marine species to be analyzed for proteome HNE modification. HNE adduction of specific proteins physiologically sequesters reactive oxygen species, which enhances fitness and resilience during environmental change.Proteome-wide 4-hydroxy-2-nonenal signature of oxidative stress in the marine invasive tunicate &lt;i&gt;Botryllus schlosseri&lt;/i&gt;.Kültz Dietmar D, Gardell Alison M AM, DeTomaso Anthony A, Stoney Greg G, Rinkevich Baruch B, Qarri Andy A, Hamar Jens JfalseProteome-wide 4-hydroxynonenal signature of oxidative stress in marine colonial tunicatesA prominent posttranslational modification associated with oxidative stress is 4-hydroxynonenal (HNE) protein adduction. Numerous studies have assessed oxidative stress but HNE protein modification has not been determined in any marine organism. LCMS proteomics was used to identify 1052 HNE adducted proteins in the cosmopolitan tunicate Botryllus schlosseri sourced from field and laboratory populations. Adducted amino acid residues were ascertained for 1849 modified sites, of which 1195 had a maximum localization score. Most HNE modifications were at less reactive lysines (rather than more reactive cysteines). HNE modification on most sites was high as corresponding unmodified peptides were undetectable. These observations suggest that Botryllus experiences high intracellular reactive oxygen species levels, resulting in substantial lipid peroxidation. Botryllus proteins with HNE adducts show enrichment in mitochondrial, proteostasis, and cytoskeletal functions. A DIA assay library was constructed to quantify HNE adduction at 72 sites across 60 proteins and reveal significantly higher HNE adduction in laboratory versus field populations. Based on the function of HNE adducted Botryllus proteins, we propose that redox signaling contributes to regulating senescence and cytoskeleton dynamics during Botryllus development and physiology. Overall, HNE modified proteins represent promising biomarkers of oxidative stress in tunicates and other aquatic species inhabiting variable environments.Mon Sep 29 00:00:00 GMT+01:00 2025PXD0502843030139211222