Biology subjects

Reinhardt, J.

Publications and source records attributed to Reinhardt, J..

6 recordsLinked to original sources

bioRxiv2025

Pathological α-Synuclein Perturbs Nuclear Integrity

Pathological aggregates of -synuclein are a hallmark of a group of neurodegenerative disorders collectively termed synucleinopathies. The physiological function of -synuclein, and the detrimental effects of the pathological variants of -synuclein have been widely debated, but recent evidence has suggested an emerging consensus on a critical role for -synuclein in regulating synaptic function. However, a controversial role for -synuclein in nuclear function in both normal and pathogenic states has been proposed, and the degree to which -synuclein localizes within the nucleus and subsequent impact on the nucleus are poorly understood. To begin to address this controversy, we employed synucleinopathy murine and cell culture models, as well as postmortem human Lewy Body Dementia tissue to elucidate the extent to which pathological -synuclein localizes within the nuclear compartments, and the downstream consequences of this localization. We observed pathological aggregation of -synuclein within the nucleus in both murine models and human postmortem Lewy Body Dementia cortex via quantitative super resolution microscopy. In both mouse and human brain tissue the presence of -synuclein in the nucleus correlated with abnormal morphology of nuclei. This pathological accumulation of -synuclein in the nucleus was not observed in control mice, human tissue without pathology, or control cells. We subsequently examined the mechanistic consequences of pathological accumulation of -synuclein in the nucleus. Synucleinopathy models displayed increased levels of the DNA damage marker 53BP1. Furthermore, cells with pathological -synuclein exhibited elevated markers of nuclear envelope damage and abnormal expression of nuclear envelope repair markers. Our cell culture data also suggests altered RNA localization in response to pathological -synuclein accumulation within the nucleus. Lastly, we show that nuclear Lewy-like pathology leads to increased sensitivity to nuclear targeted toxins. Taken together, these results rigorously illustrate nuclear localization of pathological -synuclein with super resolution methodology and provide novel insight into the ensuing impact on nuclear integrity and function.

neuroscience↗

bioRxiv2024

Data- and knowledge-derived functional landscape of human solute carriers

Research on the understudied solute carrier (SLC) superfamily of membrane transporters would greatly profit from a comprehensive knowledgebase, synthesizing data and knowledge on different aspects of SLC function. We consolidated multi-omics data sets with selected curated information from the public domain, such as structure prediction, substrate annotation, disease association and subcellular localization. This SLC-centric knowledge is made accessible to the scientific community via a web portal, featuring interactive dashboards and a tool for family-wide, tree-based visualization of SLC properties. Making use of the systematically collected and curated data sets, we selected eight feature-dimensions to compute an integrated functional landscape of human SLCs. This landscape represents various functional aspects, harmonizing local and global features of the underlying data sets, as demonstrated by inspecting structural folds and subcellular locations of selected transporters. Based on all available data sets and their integration, we assigned a biochemical/biological function to each SLC, making it one of the largest systematic annotations of human gene function and likely acting as a blueprint for future endeavours.

systems biology↗

bioRxiv2024

The solute carrier superfamily interactome

Solute carrier (SLC) transporters form a protein superfamily that enables transmembrane transport of diverse substrates including nutrients, ions and drugs. There are about 450 different SLCs, residing in a variety of subcellular membranes. Loss-of-function of an unusually high proportion of SLC transporters is genetically associated with a plethora of human diseases, making SLCs a rapidly emerging but challenging drug target class. Knowledge of their protein environment may elucidate the molecular basis for their functional integration with metabolic and cellular pathways and help conceive pharmacological interventions based on modulating proteostatic regulation. We aimed at obtaining a global survey of the SLC protein interaction landscape and mapped the protein-protein interactions of 396 SLCs by interaction proteomics. We employed a functional assessment based on RNA interference of interactors in combination with measurement of protein stability and localization. As an example, we detail the role of a SLC16A6 phospho-degron, and the contributions of PDZ-domain proteins LIN7C and MPP1 to the trafficking of SLC43A2. Overall, our work offers a resource for SLC-protein interactions for the scientific community.

systems biology↗

bioRxiv2023

Engineering of a biosensor for intracellular aspartate

Aspartate is a limiting metabolite in proliferating cells with its production closely linked to glutamine and mitochondrial metabolism. To date, measuring aspartate concentrations in live cells was deemed impossible. We present iAspSnFR, a genetically-encoded biosensor for intracellular aspartate, engineered by displaying and screening biosensor libraries in HEK293 cells. In live cells, iAspSnFR exhibits a dynamic range of 130% fluorescence change and detects reduced aspartate levels upon glutamine deprivation or glutaminase inhibition. Furthermore, iAspSnFR tracks aspartate uptake by excitatory amino acid transporters, or of asparagine after co-expression of an asparaginase. Importantly, iAspSnFR reports aspartate depletions upon electron transport chain inhibition, and therefore it can serve as a proxy for mitochondrial respiration. Consequently, iAspSnFR can dissect the major cellular pathways of aspartate production, offering immediate applications, particularly in cancer biology, such as screening small molecules targeting aspartate and glutamine metabolism.

cell biology↗

bioRxiv2023

Drug-induced eRF1 degradation promotes readthrough and reveals a new branch of ribosome quality control

Suppression of premature termination codons (PTC) by translational readthrough is a promising strategy to treat a wide variety of severe genetic diseases caused by nonsense mutations. Here, we present two novel and potent readthrough promoters - NVS1.1 and NVS2.1 - that restore substantial levels of functional full-length CFTR and IDUA proteins in disease models for cystic fibrosis and Hurler syndrome, respectively. In contrast to other readthrough promoters that affect stop codon decoding, the NVS compounds stimulate PTC suppression by triggering rapid proteasomal degradation of the translation termination factor eRF1. Our results show that this occurs by trapping eRF1 in the terminating ribosome, causing ribosome stalls and subsequent ribosome collisions, activating a novel branch of the ribosome-associated quality control (RQC) network that involves the translational stress sensor GCN1 and the catalytic activity of the E3 ubiquitin ligases RNF14 and RNF25.

molecular biology↗

bioRxiv2022

Regional context for balancing sagebrush- and woodland-dependent songbird needs with targeted pinyon-juniper management in the sagebrush biome

Tree expansion among historic grassland and shrubland systems is a global phenomenon, which results in dramatic influences on ecosystem processes and wildlife populations. In the western US, pinyon-juniper woodlands have expanded by as much as six-fold among sagebrush steppe landscapes since the late nineteenth century, with demonstrated negative impacts to the behavior, demography, and population dynamics of species that rely on intact sagebrush rangelands. Notably, greater sage-grouse (Centrocercus urophasianus) are unable to tolerate even low conifer cover, which can result in population declines and local extirpation. Removing expanding conifer cover has been demonstrated to increase sage grouse population growth rates and sagebrush-obligate songbird abundance. However, advances in restoring sagebrush habitats have been met with concern about unintended impacts to species that rely on conifer woodlands, notably the pinyon jay (Gymnorhinus cyanocephalus) whose population declines are distinctive among birds breeding in pinyon-juniper woodlands. We modeled indices to abundance in relation to multi-scale habitat features for nine songbirds reliant on both sagebrush and pinyon-juniper woodlands for breeding. Findings demonstrate that targeted sage grouse habitat restoration under the Sage Grouse Initiative is not at odds with protection of pinyon jay populations. Rather, conifer management has largely occurred in the northern sagebrush ecosystem where models suggest that past cuts likely benefit Brewers sparrow and sage thrasher while avoiding pinyon jay habitat. Extending our spatial modeling further south beyond the sagebrush biome could better equip conservationists with more comprehensive decision-support, particularly where pinyon jays face additional pressures of drought-induced tree mortality.

ecology↗