Publications by authors named "Rudiger Hell"

Article Synopsis
  • * Research in mice shows that the absence of certain TRPC channel proteins (specifically TRPC5) leads to a significant reduction in adrenaline release during insulin-induced hypoglycemia.
  • * There is a newly identified signaling pathway where specific receptor activation leads to TRPC5 channel stimulation, impacting adrenaline secretion, with similar plasma metabolite changes noted in both TRPC5-deficient mice and HAAF patients.
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  • Rice grains often have high arsenic levels and low essential nutrients, which can impact human health and nutrition.
  • Researchers created genetically modified rice that expresses a mutant gene (astol1) to boost cysteine production and reduce arsenic accumulation.
  • This modified rice showed increased essential nutrient levels and improved arsenic tolerance, suggesting a promising approach to both enhance nutrition and decrease toxicity in rice.
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Understanding the interplay of the proteome and the metabolome helps to understand cellular regulation and response. To enable robust inferences from such multi-omics analyses, we introduced and evaluated a workflow for combined proteome and metabolome analysis starting from a single sample. Specifically, we integrated established and individually optimized protocols for metabolomic and proteomic profiling (EtOH/MTBE and autoSP3, respectively) into a unified workflow (termed MTBE-SP3), and took advantage of the fact that the protein residue of the metabolomic sample can be used as a direct input for proteome analysis.

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In humans and plants, 40% of the proteome is cotranslationally acetylated at the N-terminus by a single Nα-acetyltransferase (Nat) termed NatA. The core NatA complex is comprised of the catalytic subunit Nα-acetyltransferase 10 (NAA10) and the ribosome-anchoring subunit NAA15. The regulatory subunit Huntingtin Yeast Partner K (HYPK) and the acetyltransferase NAA50 join this complex in humans.

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Aim: Although of potential biomedical relevance, dipeptide metabolism has hardly been studied. We found the dipeptidase carnosinase-2 (CN2) to be abundant in human proximal tubules, which regulate water and solute homeostasis. We therefore hypothesized, that CN2 has a key metabolic role, impacting proximal tubular transport function.

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The ribosome-tethered N-terminal acetyltransferase A (NatA) acetylates 52% of soluble proteins in Arabidopsis thaliana. This co-translational modification of the N terminus stabilizes diverse cytosolic plant proteins. The evolutionary conserved Huntingtin yeast partner K (HYPK) facilitates NatA activity in planta, but in vitro, its N-terminal helix α1 inhibits human NatA activity.

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Exercise and increased physical activity are vital components of the standard treatment guidelines for many chronic diseases such as diabetes, obesity and cardiovascular disease. Although strenuous exercise cannot be recommended to people with numerous chronic conditions, walking is something most people can perform. In comparison to high-intensity training, the metabolic consequences of low-intensity walking have been less well studied.

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Metabolomic and proteomic analyses of human plasma and serum samples harbor the power to advance our understanding of disease biology. Pre-analytical factors may contribute to variability and bias in the detection of analytes, especially when multiple labs are involved, caused by sample handling, processing time, and differing operating procedures. To better understand the impact of pre-analytical factors that are relevant to implementing a unified proteomic and metabolomic approach in a clinical setting, we assessed the influence of temperature, sitting times, and centrifugation speed on the plasma and serum metabolomes and proteomes from six healthy volunteers.

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Selenium is an essential trace element required for seleno-protein synthesis in many eukaryotic cells excluding higher plants. However, a substantial fraction of organically bound selenide in human nutrition is directly or indirectly derived from plants, which assimilate inorganic selenium into organic seleno-compounds. In humans, selenium deficiency is associated with several health disorders Despite its importance for human health, selenium assimilation and metabolism is barely understood in plants.

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In humans, the Huntingtin yeast partner K (HYPK) binds to the ribosome-associated -acetyltransferase A (NatA) complex that acetylates ~40% of the proteome in humans and . However, the relevance of HYPK for determining the human N-acetylome is unclear. Here, we identify the HYPK protein as the first in vivo regulator of NatA activity in plantsHYPK physically interacts with the ribosome-anchoring subunit of NatA and promotes N-terminal acetylation of diverse NatA substrates.

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Metabolic profiling harbors the potential to better understand various disease entities such as cancer, diabetes, Alzheimer's, Parkinson's disease or COVID-19. To better understand such diseases and their intricate metabolic pathways in human studies, model animals are regularly used. There, standardized rearing conditions and uniform sampling strategies are prerequisites towards a successful metabolomic study that can be achieved through model organisms.

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N-terminal protein acetylation (NTA) is a prevalent protein modification essential for viability in animals and plants. The dominant executor of NTA is the ribosome tethered N-acetyltransferase A (NatA) complex. However, the impact of NatA on protein fate is still enigmatic.

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Reactive carbonyl species (RCS) are spontaneously formed in the metabolism and modify and impair the function of DNA, proteins and lipids leading to several organ complications. In zebrafish, knockout of the RCS detoxifying enzymes glyoxalase 1 (Glo 1), aldehyde dehydrogenase 3a1 (Aldh3a1) and aldo-ketoreductase 1a1a (Akr1a1a) showed a signature of elevated RCS which specifically regulated glucose metabolism, hyperglycemia and diabetic organ damage. aldh2.

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Article Synopsis
  • The NatA and NatB complexes play a key role in acetylating a significant portion of proteins (60%) and are crucial for plant stress responses, particularly in drought and pathogen resistance as well as adapting to high salinity.
  • The study focuses on the sensitivity of NatB mutants to ER stress caused by dithiothreitol (DTT) and tunicamycin (TM), finding that NatB mutants are more sensitive to DTT due to an over-reduction in the cytosol rather than the buildup of misfolded proteins.
  • Results indicate that N-terminal acetylation (NTA) in plants does not hinder protein targeting to the ER as previously thought, and the role of the ubiquitin lig
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Background: Amino acids have a central role in cell metabolism, and intracellular changes contribute to the pathogenesis of various diseases, while the role and specific organ distribution of dipeptides is largely unknown.

Method: We established a sensitive, rapid and reliable UPLC-MS/MS method for quantification of 36 dipeptides. Dipeptide patterns were analyzed in brown and white adipose tissues, brain, eye, heart, kidney, liver, lung, muscle, sciatic nerve, pancreas, spleen and thymus, serum and urine of C57BL/6N wildtype mice and related to the corresponding amino acid profiles.

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The uptake of sulfate by roots and its reductive assimilation mainly in the leaves are not only essential for plant growth and development but also for defense responses against biotic and abiotic stresses. The latter functions result in stimulus-induced fluctuations of sulfur demand at the cellular level. However, the maintenance and acclimation of sulfur homeostasis at local and systemic levels is not fully understood.

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In the past, reactive nitrogen species (RNS) were supposed to be stress-induced by-products of disturbed metabolism that cause oxidative damage to biomolecules. However, emerging evidence demonstrates a substantial role of RNS as endogenous signals in eukaryotes. In plants, S-nitrosoglutathione (GSNO) is the dominant RNS and serves as the NO donor for S-nitrosation of diverse effector proteins.

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Increased acrolein (ACR), a toxic metabolite derived from energy consumption, is associated with diabetes and its complications. However, the molecular mechanisms are mostly unknown, and a suitable animal model with internal increased ACR does not exist for in vivo studying so far. Several enzyme systems are responsible for acrolein detoxification, such as Aldehyde Dehydrogenase (ALDH), Aldo-Keto Reductase (AKR), and Glutathione S-Transferase (GST).

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Photorespiration is an integral component of plant primary metabolism. Accordingly, it has been often observed that impairing the photorespiratory flux negatively impacts other cellular processes. In this study, the metabolic acclimation of the wild type was compared with the hydroxypyruvate reductase 1 (HPR1; ) mutant, displaying only a moderately reduced photorespiratory flux.

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Iron-sulfur (Fe-S) clusters are ubiquitous cofactors in all life and are used in a wide array of diverse biological processes, including electron transfer chains and several metabolic pathways. Biosynthesis machineries for Fe-S clusters exist in plastids, the cytosol, and mitochondria. A single monothiol glutaredoxin (GRX) is involved in Fe-S cluster assembly in mitochondria of yeast and mammals.

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Rice grains typically contain high levels of toxic arsenic but low levels of the essential micronutrient selenium. Anthropogenic arsenic contamination of paddy soils exacerbates arsenic toxicity in rice crops resulting in substantial yield losses. Here, we report the identification of the gain-of-function arsenite tolerant 1 (astol1) mutant of rice that benefits from enhanced sulfur and selenium assimilation, arsenic tolerance, and decreased arsenic accumulation in grains.

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Uncontrolled proliferation and altered metabolic reprogramming are hallmarks of cancer. Active glycolysis and glutaminolysis are characteristic features of these hallmarks and required for tumorigenesis. A fine balance between cancer metabolism and autophagy is a prerequisite of homeostasis within cancer cells.

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Regulation of glucose homeostasis is a fundamental process to maintain blood glucose at a physiological level, and its dysregulation is associated with the development of several metabolic diseases. Here, we report on a zebrafish mutant for Aldo-keto-reductase 1a1b () as a regulator of gluconeogenesis. Adult mutant zebrafish developed fasting hypoglycemia, which was caused by inhibiting phosphoenolpyruvate carboxykinase (PEPCK) expression as rate-limiting enzyme of gluconeogenesis.

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Increased methylglyoxal (MG) formation is associated with diabetes and its complications. In zebrafish, knockout of the main MG detoxifying system Glyoxalase 1, led to limited MG elevation but significantly elevated aldehyde dehydrogenases (ALDH) activity and aldh3a1 expression, suggesting the compensatory role of Aldh3a1 in diabetes. To evaluate the function of Aldh3a1 in glucose homeostasis and diabetes, aldh3a1 zebrafish mutants were generated using CRISPR-Cas9.

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