502 results match your criteria: "Institute of Biology II[Affiliation]"

Small molecules mediate cellular reprogramming across two kingdoms.

J Exp Bot

December 2021

Institute of Biology II, Faculty of Biology, Albert-Ludwigs-University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany.

The fertilized egg is the single totipotent cell from which multicellular organisms arise through the processes of cell division and differentiation. While animals typically lose their capacity to redifferentiate cells that are already fully differentiated, plant cells are thought to remain totipotent (Su et al., 2020).

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Methods of In Situ Quantitative Root Biology.

Plants (Basel)

November 2021

Instituto de Bioingeniería, Universidad Miguel Hernández, 03202 Elche, Spain.

When dealing with plant roots, a multiscale description of the functional root structure is needed. Since the beginning of 21st century, new devices such as laser confocal microscopes have been accessible for coarse root structure measurements, including three-dimensional (3D) reconstruction. Most researchers are familiar with using simple 2D geometry visualization that does not allow quantitative determination of key morphological features from an organ-like perspective.

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Quantitative high-confidence human mitochondrial proteome and its dynamics in cellular context.

Cell Metab

December 2021

Institute of Biology II, Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany. Electronic address:

Mitochondria are key organelles for cellular energetics, metabolism, signaling, and quality control and have been linked to various diseases. Different views exist on the composition of the human mitochondrial proteome. We classified >8,000 proteins in mitochondrial preparations of human cells and defined a mitochondrial high-confidence proteome of >1,100 proteins (MitoCoP).

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In previous studies, the superhydrophilic skin of moisture-harvesting lizards has been linked to the morphological traits of the lizards' integument, that is, the occurrence of honeycomb-shaped microstructures. Interestingly, these structures can also cover the skin of lizards inhabiting wet habitats. We therefore tested the influence of the microstructures' main features on the habitat choice and wettability in the genus .

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Quantitative proteomics identifies the universally conserved ATPase Ola1p as a positive regulator of heat shock response in Saccharomyces cerevisiae.

J Biol Chem

November 2021

Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany. Electronic address:

The universally conserved P-loop ATPase Ola1 is implicated in various cellular stress response pathways, as well as in cancer and tumor progression. However, Ola1p functions are divergent between species, and the involved mechanisms are only poorly understood. Here, we studied the role of Ola1p in the heat shock response of the yeast Saccharomyces cerevisiae using a combination of quantitative and pulse labeling-based proteomics approaches, in vitro studies, and cell-based assays.

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Subcellular proteomics.

Nat Rev Methods Primers

April 2021

Department of Biochemistry, University of Cambridge, Cambridge, UK.

The eukaryotic cell is compartmentalized into subcellular niches, including membrane-bound and membrane-less organelles. Proteins localize to these niches to fulfil their function, enabling discreet biological processes to occur in synchrony. Dynamic movement of proteins between niches is essential for cellular processes such as signalling, growth, proliferation, motility and programmed cell death, and mutations causing aberrant protein localization are associated with a wide range of diseases.

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Quantitative proteomics identifies PTP1B as modulator of B cell antigen receptor signaling.

Life Sci Alliance

November 2021

Biochemistry and Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany

B cell antigen receptor (BCR) signaling is initiated by protein kinases and limited by counteracting phosphatases that currently are less well studied in their regulation of BCR signaling. Here, we used the B cell line Ramos to identify and quantify human B cell signaling components. Specifically, a protein tyrosine phosphatase profiling revealed a high expression of the protein tyrosine phosphatase 1B (PTP1B) in Ramos and human naïve B cells.

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RETRACTED: Enhanced AC133-specific CAR T cell therapy induces durable remissions in mice with metastatic small cell lung cancer.

Cancer Lett

November 2021

Department of Medicine I, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; BIOSS Center for Biological Signalling Studies, University of Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Germany.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).

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For successful material deployment in tissue engineering, the material itself, its mechanical properties, and the microscopic geometry of the product are of particular interest. While silk is a widely applied protein-based tissue engineering material with strong mechanical properties, the size and shape of artificially spun silk fibers are limited by existing processes. This study adjusts a microfluidic spinneret to manufacture micron-sized wet-spun fibers with three different materials enabling diverse geometries for tissue engineering applications.

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Maintaining proteostasis under mechanical stress.

EMBO Rep

August 2021

Institute of Biology II, Faculty of Biology, and Signalling Research Centres BIOSS and CIBSS, Albert-Ludwigs-University Freiburg, Freiburg, Germany.

Cell survival, tissue integrity and organismal health depend on the ability to maintain functional protein networks even under conditions that threaten protein integrity. Protection against such stress conditions involves the adaptation of folding and degradation machineries, which help to preserve the protein network by facilitating the refolding or disposal of damaged proteins. In multicellular organisms, cells are permanently exposed to stress resulting from mechanical forces.

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Editorial: How Cells Build Plants: Regulatory Mechanisms for Integrated Functioning of Plant Cells and the Whole Plant Body.

Front Plant Sci

July 2021

Centre for BioSystems Analysis, BIOSS Centre for Biological Signalling Studies, Institute of Biology II/Molecular Plant Physiology, University of Freiburg, Freiburg, Germany.

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Histone H2AX phosphorylated at serine 139 (γ-H2AX) is a hallmark of DNA damage, signaling the presence of DNA double-strand breaks and global replication stress in mammalian cells. While γ-H2AX can be visualized with antibodies in fixed cells, its detection in living cells was so far not possible. Here, we used immune libraries and phage display to isolate nanobodies that specifically bind to γ-H2AX.

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DNA Repair Protein APE1 Degrades Dysfunctional Abasic mRNA in Mitochondria Affecting Oxidative Phosphorylation.

J Mol Biol

September 2021

Department of Medicine, University of Udine, 33100 Udine, Italy; Laboratory of Mitochondrial Biogenesis, Centre of New Technologies, University of Warsaw, 02-097 Warsaw, Poland. Electronic address:

APE1 is a multifunctional protein which plays a central role in the maintenance of nuclear and mitochondrial genomes repairing DNA lesions caused by oxidative and alkylating agents. In addition, it works as a redox signaling protein regulating gene expression by interacting with many transcriptional factors. Apart from these canonical activities, recent studies have shown that APE1 is also enzymatically active on RNA molecules.

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Autophosphorylation of the KaiC-like protein ArlH inhibits oligomerization and interaction with ArlI, the motor ATPase of the archaellum.

Mol Microbiol

September 2021

Molecular Biology of Archaea and Signaling Research Centre BIOSS, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany.

Motile archaea are propelled by the archaellum, whose motor complex consists of the membrane protein ArlJ, the ATPase ArlI, and the ATP-binding protein ArlH. Despite its essential function and the existence of structural and biochemical data on ArlH, the role of ArlH in archaellum assembly and function remains elusive. ArlH is a structural homolog of KaiC, the central component of the cyanobacterial circadian clock.

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The Pleiades are a cluster of fungal effectors that inhibit host defenses.

PLoS Pathog

June 2021

Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Vienna BioCenter (VBC), Vienna, Austria.

Biotrophic plant pathogens secrete effector proteins to manipulate the host physiology. Effectors suppress defenses and induce an environment favorable to disease development. Sequence-based prediction of effector function is impeded by their rapid evolution rate.

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Expanding the SiMPl Plasmid Toolbox for Use with Spectinomycin/Streptomycin.

ACS Omega

June 2021

Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestraße 18, 79104 Freiburg, Germany.

We recently developed the SiMPl plasmid toolbox, which is constituted by pairs of plasmids, generically indicated as pSiMPl_N and pSiMPl_C, which can be stably maintained in with a single antibiotic x. The method exploits the split intein gp41-1 to reconstitute the enzyme conferring resistance toward the antibiotic x, whereby each enzyme fragment is expressed from one of the plasmids in the pair. pSiMPl plasmids are currently available for use with ampicillin, kanamycin, chloramphenicol, hygromycin, and puromycin.

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Article Synopsis
  • Cyanobacteria produce type IV pili, critical for movement, attachment, and natural transformation; the main component is the major pilin PilA1, with additional minor pilins present.
  • The study found that the minor pilin PilA5 is crucial for natural transformation but not for movement or clumping, while other minor pilins from the pilA9-slr2019 unit are essential for motility but not for transformation.
  • Gene expression analysis revealed that the levels of minor pilin genes change when the bacteria come into contact with surfaces, indicating their role in different pilus functions and the potential for forming aggregated structures.
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The archaeal protein SepF is essential for cell division in Haloferax volcanii.

Nat Commun

June 2021

Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, University of Freiburg, Freiburg, Germany.

In most bacteria, cell division depends on the tubulin homolog FtsZ and other proteins, such as SepF, that form a complex termed the divisome. Cell division also depends on FtsZ in many archaea, but other components of the divisome are unknown. Here, we demonstrate that a SepF homolog plays important roles in cell division in Haloferax volcanii, a halophilic archaeon that is known to have two FtsZ homologs with slightly different functions (FtsZ1 and FtsZ2).

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DIMA: Data-Driven Selection of an Imputation Algorithm.

J Proteome Res

July 2021

Institute of Medical Biometry and Statistics (IMBI), Institute of Medicine and Medical Center Freiburg, 79104 Freiburg im Breisgau, Germany.

Imputation is a prominent strategy when dealing with missing values (MVs) in proteomics data analysis pipelines. However, it is difficult to assess the performance of different imputation methods and varies strongly depending on data characteristics. To overcome this issue, we present the concept of a data-driven selection of an imputation algorithm (DIMA).

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In sarcomeres, α-actinin cross-links actin filaments and anchors them to the Z-disk. FATZ (filamin-, α-actinin-, and telethonin-binding protein of the Z-disk) proteins interact with α-actinin and other core Z-disk proteins, contributing to myofibril assembly and maintenance. Here, we report the first structure and its cellular validation of α-actinin-2 in complex with a Z-disk partner, FATZ-1, which is best described as a conformational ensemble.

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Integrity of and damage to wings, feather vanes and serrations in barn owls.

Zoology (Jena)

August 2021

Institute of Biology II, RWTH Aachen University, Worringerweg 3, D-52074, Aachen, Germany. Electronic address:

The silent flight of owls is well known. It has served as role model for the designs of new airplane wings and ventilators. One of the structural features that underlies silent flight is the serrated leading edge of the wing that is mainly formed by the tenth primary flight feather (P10).

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CYTH proteins make up a large superfamily that is conserved in all three domains of life. These enzymes have a triphosphate tunnel metalloenzyme (TTM) fold, which typically results in phosphatase functions, e.g.

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The Universally Conserved ATPase YchF Regulates Translation of Leaderless mRNA in Response to Stress Conditions.

Front Mol Biosci

May 2021

Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.

The universally conserved P-loop GTPases control diverse cellular processes, like signal transduction, ribosome assembly, cell motility, and intracellular transport and translation. YchF belongs to the Obg-family of P-loop GTPases and is one of the least characterized member of this family. It is unique because it preferentially hydrolyses ATP rather than GTP, but its physiological role is largely unknown.

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Extracellular ATP has been described to be involved in inflammatory cytokine production by human testicular peritubular cells (HTPCs). The ectonucleotidases ENTPD1 and NT5E degrade ATP and have been reported in rodent testicular peritubular cells. We hypothesized that if a similar situation exists in human testis, ATP metabolites may contribute to cytokine production.

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