A5090660216- Fungal and yeast genetics research
- Microbial Metabolic Engineering and Bioproduction
- Biofuel production and bioconversion
- Fermentation and Sensory Analysis
- Plant-Microbe Interactions and Immunity
- Photosynthetic Processes and Mechanisms
- Nitric Oxide and Endothelin Effects
- Mitochondrial Function and Pathology
- Polysaccharides and Plant Cell Walls
- Glycosylation and Glycoproteins Research
- Neuropeptides and Animal Physiology
- Viral Infectious Diseases and Gene Expression in Insects
- Lipid Membrane Structure and Behavior
- Plant Reproductive Biology
- Protein Kinase Regulation and GTPase Signaling
- RNA and protein synthesis mechanisms
- Probiotics and Fermented Foods
- Erythrocyte Function and Pathophysiology
- Gene Regulatory Network Analysis
- Peptidase Inhibition and Analysis
- Neuroscience of respiration and sleep
- Mycotoxins in Agriculture and Food
- Endoplasmic Reticulum Stress and Disease
- Bacterial Genetics and Biotechnology
- Collagen: Extraction and Characterization
National Institute for Public Health and the Environment
2010-2021
University of Amsterdam
2007-2020
Medizinische Hochschule Hannover
2010
Netherlands Institute for Neuroscience
2010
Amsterdam UMC Location University of Amsterdam
2010
Ghent University
1992-1995
Uppsala University
1992
Robert Bosch (Germany)
1964
Amsterdam University of Applied Sciences
1958
Access to Nutrition Foundation
1947-1950
The specific pH values of cellular compartments affect virtually all biochemical processes, including enzyme activity, protein folding and redox state. Accurate, sensitive compartment-specific measurements intracellular (pHi) dynamics in living cells are therefore crucial to the understanding stress response adaptation. We used pH-sensitive GFP derivative 'ratiometric pHluorin' expressed cytosol mitochondrial matrix growing Saccharomyces cerevisiae assess variation cytosolic (pHcyt) (pHmit)...
Recognition of lipids by proteins is important for their targeting and activation in many signaling pathways, but the mechanisms that regulate such interactions are largely unknown. Here, we found binding to ubiquitous lipid phosphatidic acid (PA) depended on intracellular pH protonation state its phosphate headgroup. In yeast, a rapid decrease response glucose starvation regulated PA transcription factor, Opi1, coordinately repressed phospholipid metabolic genes. This enabled coupling...
Realistic quantitative models require data from many laboratories. Therefore, standardization of experimental systems and assay conditions is crucial. Moreover, standards should be representative the in vivo conditions. However, most often, enzyme–kinetic parameters are measured under that yield maximum activity each enzyme. In practice, this means kinetic different enzymes buffers, at pH values, with ionic strengths, etc. a joint effort Dutch Vertical Genomics Consortium, European Yeast...
ABSTRACT Weak organic acids are naturally occurring compounds that commercially used as preservatives in the food and beverage industries. They extend shelf life of products by inhibiting microbial growth. There a number theories explain antifungal properties these weak acids, but exact mechanism is still unknown. We set out to quantitatively determine contributions various mechanisms activity well yeast uses counteract their effects. analyzed effects four differing lipophilicity (sorbic,...
All organisms have evolved to cope with changes in environmental conditions, ensuring the optimal combination of proliferation and survival. In yeast, exposure a mild stress leads an increased tolerance for other stresses. This suggests that yeast uses information from environment prepare future threats. We used knockout collection systematically investigate genes functions involved severe survival acquisition (cross-) tolerance. Besides relevant heat, acid, oxidative stress, we found...
Abstract Background Because protonation affects the properties of almost all molecules in cells, cytosolic pH (pH c ) is usually assumed to be constant. In model organism yeast, however, changes response presence nutrients and varies during growth. Since small can lead major metabolism, signal transduction, phenotype, we decided analyze control. Results Introducing a pH-sensitive reporter protein into yeast deletion collection allowed quantitative genome-wide analysis live, growing cultures....
The solubilities of polyethers are surprisingly counter-intuitive. best-known example is the difference between polyethylene glycol ([-CH2-CH2-O-]n) which infinitely soluble, and polyoxymethylene ([-CH2-O-]n) completely insoluble in water, exactly opposite what one expects from C/O ratios these molecules. Similar anomalies exist for oligomeric cyclic polyethers. To solve this apparent mystery, we use femtosecond vibrational GHz dielectric spectroscopy with complementary ab initio...
Weak organic acids (WOA) are widely used preservatives to prevent fungal spoilage of foods and beverages. Exposure baker's yeast Saccharomyces cerevisiae WOA leads cellular acidification anion accumulation. Pre-adaptation cultures reduced the rate caused by weak acid exposure, most likely as a result changes in plasma membrane or cell wall composition. In order adapt sublethal concentrations grow, cells activate ATP consuming transporters remove protons anions. We explored what extent...
Cells are extremely crowded, and a central question in biology is how this affects the intracellular water. Here, we use ultrafast vibrational spectroscopy dielectric-relaxation to observe random orientational motion of water molecules inside living cells three prototypical organisms: Escherichia coli, Saccharomyces cerevisiae (yeast), spores Bacillus subtilis. In all organisms, most exhibits same as neat (characteristic time constants ~9 ~2 ps for first-order second-order correlation...
A method is described for the quantitative estimation of periodic acid-Schiff positive substances in solutions tissue components. It was found that hyaluronic acid and chondroitinsulphuric are negative. Any coloration observed could be ascribed to contaminating polysaccharides probably not or exclusively composed hexosamine hexuronic acid. Unlike groups, groups attacked by without formation, however, aldehyde groups. The chemistry this process discussed.
A major challenge in systems biology lies the integration of processes occurring at different levels, such as transcription, translation, and metabolism, to understand functioning a living cell its environment. We studied high temperature-induced glycolytic flux increase Saccharomyces cerevisiae investigated regulatory mechanisms underlying this increase. used glucose-limited chemostat cultures separate effects temperature from on growth rate. Growth increased (38 degrees C versus 30 C)...
The conserved protein kinase Sch9 is a central player in the nutrient-induced signaling network yeast, although only few of its direct substrates are known. We now provide evidence that controls vacuolar proton pump (V-ATPase) to maintain cellular pH homeostasis and ageing. A synthetic sick phenotype arises when deletion SCH9 combined with dysfunctional V-ATPase, lack has significant impact on cytosolic (pHc) homeostasis. physically interacts with, influences glucose-dependent...
The contribution of nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) to non‐adrenergic non‐cholinergic (NANC) relaxations in the pig gastric fundus was investigated. Circular longitudinal muscle strips were mounted for isotonic registration presence atropine guanethidine; tone raised with 5‐hydroxytryptamine. Electrical field stimulation 10 s trains at 5 min intervals induced short‐lasting, frequency‐dependent while continuous cumulative increase frequency sustained both types...
The weak organic acid sorbic is a commonly used food preservative, as it inhibits the growth of bacteria, yeasts, and molds. We have genome-wide transcriptional profiling Bacillus subtilis cells during mild stress to reveal growth-inhibitory activity this preservative identify potential resistance mechanisms. Our analysis demonstrated that acid-stressed induce responses normally seen upon nutrient limitation. This indicated by strong derepression CcpA, CodY, Fur regulon induction...
Spatial sorting to discrete quality control sites in the cell is a process harnessing toxicity of aberrant proteins. We show that yeast t-snare phosphoprotein syntaxin5 (Sed5) acts as key factor mitigating proteotoxicity and spatial deposition clearance IPOD (insoluble protein deposit) inclusions associates with disaggregase Hsp104. Sed5 phosphorylation promotes dynamic movement COPII-associated Hsp104 boosts disaggregation by favoring anterograde ER-to-Golgi trafficking. Hsp104-associated...
Maintenance of an optimal redox environment is critical for appropriate functioning cellular processes and cell survival. Despite the importance maintaining homeostasis, it not clear how potential sensed set, that impact on a cellular/organellar level are poorly understood. The genetic bases homeostasis were investigated using green fluorescent protein (GFP) based probe, roGFP2 pH sensitive GFP-based pHluorin. use roGFP2, in conjunction with pHluorin, enabled determination pH-adjusted...
Abstract Background The COVID-19 pandemic has disrupted routine measles immunisation and supplementary activities (SIAs) in most countries including Kenya. We assessed the risk of outbreaks during Kenya as a case study for African Region. Methods Combining serological data, local contact patterns, vaccination coverage into cohort model, we predicted age-adjusted population immunity estimated probability when contact-reducing interventions are lifted. considered various scenarios reduced from...
Candida glabrata is an opportunistic fungal pathogen which a growing concern for immunocompromised patients. It ranked as the second most common cause of candidiasis after albicans. For pathogenic yeasts, intracellular pH (pHi) has been implicated in proliferation, dimorphic switching and virulence. We expressed pH-sensitive green fluorescent protein variant ratiometric pHluorin cytosol C. to study pHi dynamics living cells. evaluated response various growth stress conditions encountered...