A5090045544- Fungal and yeast genetics research
- Plant Reproductive Biology
- Cellular transport and secretion
- Plant Molecular Biology Research
- Plant nutrient uptake and metabolism
- Nonlinear Dynamics and Pattern Formation
- Lipid Membrane Structure and Behavior
- Photosynthetic Processes and Mechanisms
- Microtubule and mitosis dynamics
- Fermentation and Sensory Analysis
- Genomics and Chromatin Dynamics
- Diffusion and Search Dynamics
- Plant Stress Responses and Tolerance
- Gene Regulatory Network Analysis
- Bacterial Genetics and Biotechnology
- Fungal Biology and Applications
- Light effects on plants
- Protein Kinase Regulation and GTPase Signaling
- RNA Interference and Gene Delivery
- Protein Tyrosine Phosphatases
- Legume Nitrogen Fixing Symbiosis
- Caveolin-1 and cellular processes
- Adenosine and Purinergic Signaling
- Virus-based gene therapy research
- Genetics, Aging, and Longevity in Model Organisms
University of Lausanne
2014-2024
University of Zurich
2005-2010
Purdue University West Lafayette
2005
Ruhr University Bochum
2005
Summary Directional transport of the phytohormone auxin is required for establishment and maintenance plant polarity, but underlying molecular mechanisms have not been fully elucidated. Plant homologs human multiple drug resistance/P‐glycoproteins (MDR/PGPs) implicated in transport, as defects MDR1 ( AtPGP19 ) AtPGP1 result reductions growth Arabidopsis atpgp1 , atpgp19 ), maize brachytic2 sorghum dwarf3 ). Here we examine localization, activity, substrate specificity inhibitor sensitivity...
Here we show that related isoform AtPGP4 is expressed predominantly during early root development. loss‐of‐function plants reveal enhanced lateral initiation and hair lengths both known to be under the control of auxin. Further, atpgp4 altered sensitivities toward auxin transport inhibitor, NPA. Finally, mutant roots elevated free levels reduced capacities. These results together with yeast growth assays suggest a direct involvement in processes controlling
The rate, polarity, and symmetry of the flow plant hormone auxin are determined by polar cellular localization PIN-FORMED (PIN) efflux carriers. Flavonoids, a class secondary metabolites, have been suspected to modulate transport tropic responses. Nevertheless, identity specific flavonoid compounds involved their molecular function targets in vivo essentially unknown. Here we show that root elongation zone agravitropic pin2/eir1/wav6/agr1 has an altered pattern amount flavonol glycosides....
The immunophilin-like protein TWISTED DWARF1 (TWD1/FKBP42) has been shown to physically interact with the multidrug resistance/P-glycoprotein (PGP) ATP-binding cassette transporters PGP1 and PGP19 (MDR1). Overlapping phenotypes of pgp1/pgp19 twd1 mutant plants suggested a positive regulatory role TWD1 in PGP-mediated export plant hormone auxin, which controls development. Here, we provide evidence at cellular levels that auxin transport. cells showed greatly reduced native indole-3-acetic...
Abstract Plants strictly regulate the uptake and distribution of Zn, which is essential for plant growth development. Here, we show that Arabidopsis thaliana PCR2 Zn redistribution detoxification. The pcr2 loss-of-function mutant was compromised in growth, both Zn-excessive -deficient conditions. roots accumulated more than did control plants, whereas plants overexpressing contained less indicating removes from roots. Consistent with a role as Zn-efflux transporter, reduced intracellular...
The immunophilin-like FKBP42 TWISTED DWARF1 (TWD1) has been shown to control plant development via the positive modulation of ABCB/P-glycoprotein (PGP)-mediated transport hormone auxin. TWD1 functionally interacts with two closely related proteins, ABCB1/PGP1 and ABCB19/PGP19/MDR1, both which exhibit ability bind be inhibited by synthetic auxin inhibitor N-1-naphylphtalamic acid (NPA). They are also flavonoid compounds, suspected modulators transport. mechanisms flavonoids NPA interfere...
The small Rho-family GTPase Cdc42 is critical for cell polarization and polarizes spontaneously in absence of upstream spatial cues. Spontaneous thought to require dynamic recycling through Guanine nucleotide Dissociation Inhibitor (GDI)-mediated membrane extraction vesicle trafficking. Here, we describe a functional fluorescent allele fission yeast, which demonstrates dynamics independent these pathways. Furthermore, an engineered targeted the independently pathways by amphipathic helix...
Plant development and physiology are widely determined by the polar transport of signaling molecule auxin. This process is controlled on cellular efflux level catalyzed members PIN (pin-formed) ABCB (ATP-binding cassette protein subfamily B)/P-glycoprotein family that can function independently coordinately. In this study, we have identified means chemical genomics a novel auxin inhibitor (ATI), BUM (2-[4-(diethylamino)-2-hydroxybenzoyl]benzoic acid), efficiently blocks auxin-regulated plant...
The exocyst complex is essential for many exocytic events, by tethering vesicles at the plasma membrane fusion. In fission yeast, polarized exocytosis growth relies on combined action of cell poles and myosin-driven transport along actin cables. We report here identification yeast Schizosaccharomyces pombe Sec3 protein, which we identified through sequence homology its PH-like domain. Like other subunits, sec3 required secretion division. Cells deleted are only conditionally lethal can...
Local activity of the small GTPase Cdc42 is critical for cell polarization. Whereas scaffold-mediated positive feedback was proposed to break symmetry budding yeast cells and produce a single zone activity, existence similar regulation has not been probed in other organisms. Here, we address this problem using rod-shaped fission Schizosaccharomyces pombe, which exhibit zones active Cdc42-GTP at both poles. We implemented CRY2-CIB1 optogenetic system acute light-dependent protein recruitment...
Sterols are crucial components of biological membranes, which synthetized in the ER and accumulate plasma membrane (PM). Here, by applying a genetically encoded sterol biosensor (D4H), we visualize flow between PM endosomes fission yeast Schizosaccharomyces pombe. Using time-lapse correlative light-electron microscopy, found that inhibition Arp2/3-dependent F-actin assembly promotes reversible relocalization D4H from to internal sterol-rich compartments (STRIC) labeled synaptobrevin Syb1....
In non-motile fungi, sexual reproduction relies on strong morphogenetic changes in response to pheromone signaling. We report here a systematic screen for morphological abnormalities of the mating process fission yeast Schizosaccharomyces pombe. derived homothallic (self-fertile) collection viable deletions, which, upon visual screening, revealed plethora phenotypes affecting all stages process, including cell polarization, fusion and sporulation. Cell formation focus, an aster-like F-actin...
Cells self-organize using reaction-diffusion and fluid-flow principles. Whether bulk membrane flows contribute to cell patterning has not been established. Here, mathematical modeling, optogenetics, synthetic probes, we show that polarized exocytosis causes lateral away from regions of insertion. Plasma membrane–associated proteins with sufficiently low diffusion and/or detachment rates couple the deplete areas exocytosis. In rod-shaped fission yeast cells, zones Cdc42 GTPase activity...
In the fission yeast Schizosaccharomyces pombe, pheromone signaling engages a pathway composed of G protein-coupled receptor, Ras, and mitogen-activated protein kinase (MAPK) cascade that triggers sexual differentiation gamete fusion. Cell-cell fusion requires local cell wall digestion, which relies on an initially dynamic actin focus becomes stabilized upon enrichment structure. We constructed live-reporter active Ras1 (Ras1-guanosine triphosphate [GTP]) shows Ras activity at polarity sites...
Cdc42 is a Rho-family GTPase conserved across eukaryotes, where it plays essential roles in cell polarization. In single-celled yeast systems, key driver of symmetry breaking and polarized growth, forming zones activity that locally recruit effectors to organize the cytoskeleton polarize secretion. Here we show also functions cell-cell fusion during Schizosaccharomyces pombe sexual reproduction but concentrates at site through mechanisms distinct from those proposed Saccharomyces cerevisiae....
In mating fission yeast cells, sensing and response to extracellular pheromone concentrations occurs through an exploratory Cdc42 patch that stochastically samples the cell cortex before stabilizing towards a partner. Active Ras1 (Ras1-GTP), upstream regulator of Cdc42, Gap1, GTPase-activating protein for Ras1, localize at patch. We developed reaction-diffusion model appearance disappearance with positive feedback by Guanine nucleotide Exchange Factor (GEF) Gap1 inhibition. The is based on...
Local Cdc42 GTPase activation promotes polarized exocytosis, resulting in membrane flows that deplete low-mobility membrane-associated proteins from the growth region. To investigate self-organizing properties of secretion-polarization system under flow, we developed a reaction-diffusion particle model. The model includes positive feedback Cdc42, hydrolysis by GTPase-activating (GAPs), and flow-induced displacement exo/endocytosis. Simulations show how polarization relies on depletion low...
Abstract Transcription enables the production of RNA from a DNA template. Due to highly dynamic nature transcription, live‐cell imaging methods play crucial role in measuring kinetics this process. For instance, transcriptional bursts have been visualized using fluorescent phage‐coat proteins that associate tightly with messenger (mRNA) stem loops formed on nascent transcripts. To convert signal emanating transcription site into meaningful estimates dynamics, influence various parameters...
Abstract The small GTPase Cdc42 is critical for cell polarization. Scaffold-mediated positive feedback regulation was proposed to mediate symmetry-breaking a single active zone in budding yeast cells. In rod-shaped fission S. pombe cells, Cdc42-GTP localizes both poles, where it promotes bipolar growth. Here, we implement the CRY2-CIBN optogenetic system acute light-dependent protein recruitment plasma membrane, which allowed directly demonstrate feedback. Indeed, of constitutively leads...
This article probes the function of type 2C phosphatase Ptc1 and shows it participates in cell size regulation through Pom1 kinase. can dephosphorylate but modulates its localization indirectly, indicating direct indirect roles this protein phosphatase.
Abstract In non-motile fungi, sexual reproduction relies on stron morphogenetic changes in response to pheromone signaling. We report here asystematic screen for morphological abnormalities o the mating process fission yeast Schizosaccharomyces pombe . derived a homothallic (self-fertile) collection of viable deletions which, upon visual screening, revealed plethora phenotype affecting all stages process, including cell polarizati fusion and sporulation. Cell onthe formation focus, an...
Abstract Sterols are crucial components of biological membranes that help maintain membrane integrity and regulate various processes such as endocytosis, protein oligomerization signaling. Although synthetized in the ER, sterols at highest concentrations plasma (PM) all eukaryotic organisms. Here, by applying a genetically encoded sterol biosensor (D4H), we visualize flow between PM endosomes fission yeast Schizosaccharomyces pombe . While D4H is detected during steady-state growth,...