3,562 research outputs found
The High Osmolarity Glycerol Mitogen-Activated Protein Kinase regulates glucose catabolite repression in filamentous fungi
This is the final version. Available from the publisher via the DOI in this record.The utilization of different carbon sources in filamentous fungi underlies a complex regulatory network governed by signaling events of different protein kinase pathways, including
the high osmolarity glycerol (HOG) and protein kinase A (PKA) pathways. This work unraveled cross-talk events between these pathways in governing the utilization of preferred (glucose) and non-preferred (xylan, xylose) carbon sources in the reference fungus Aspergillus
nidulans. An initial screening of a library of 103 non-essential protein kinase (NPK) deletion
strains identified several mitogen-activated protein kinases (MAPKs) to be important for carbon catabolite repression (CCR). We selected the MAPKs Ste7, MpkB, and PbsA for further
characterization and show that they are pivotal for HOG pathway activation, PKA activity,
CCR via regulation of CreA cellular localization and protein accumulation, as well as for
hydrolytic enzyme secretion. Protein-protein interaction studies show that Ste7, MpkB, and
PbsA are part of the same protein complex that regulates CreA cellular localization in the
presence of xylan and that this complex dissociates upon the addition of glucose, thus allowing CCR to proceed. Glycogen synthase kinase (GSK) A was also identified as part of this
protein complex and shown to potentially phosphorylate two serine residues of the HOG
MAPKK PbsA. This work shows that carbon source utilization is subject to cross-talk regulation by protein kinases of different signaling pathways. Furthermore, this study provides a
model where the correct integration of PKA, HOG, and GSK signaling events are required
for the utilization of different carbon sources.Fundac¸ão de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Putative Membrane Receptors Contribute to Activation and Efficient Signaling of Mitogen-Activated Protein Kinase Cascades during Adaptation of Aspergillus fumigatus to Different Stressors and Carbon Sources
This is the final version. Available on open access from the American Society for Microbiology via the DOI in this recordData availability. The proteomic data set can be accessed in Table S1 at https://figshare.com/
articles/Membrane_receptors_contribute_to_activation_and_efficient_signaling_of_Mitogen-Activated
_Protein_Kinase_cascades_during_adaptation_of_Aspergillus_fumigatus_to_different_stressors_and
_carbon_sources/12402125The high-osmolarity glycerol (HOG) response pathway is a multifunctional signal transduction pathway that specifically transmits ambient osmotic signals. Saccharomyces cerevisiae Hog1p has two upstream signaling branches, the sensor histidine kinase Sln1p and the receptor Sho1p. The Sho1p branch includes two
other proteins, the Msb2p mucin and Opy2p. Aspergillus fumigatus is the leading
cause of pulmonary fungal diseases. Here, we investigated the roles played by A. fumigatus SlnASln1p, ShoASho1p, MsbAMsb2p, and OpyAOpy2p putative homologues during the activation of the mitogen-activated protein kinase (MAPK) HOG pathway.
The shoA, msbA, and opyA singly and doubly null mutants are important for the cell
wall integrity (CWI) pathway, oxidative stress, and virulence as assessed by a Galleria
mellonella model. Genetic interactions of ShoA, MsbA, and OpyA are also important
for proper activation of the SakAHog1p and MpkASlt2 cascade and the response to osmotic and cell wall stresses. Comparative label-free quantitative proteomics analysis
of the singly null mutants with the wild-type strain upon caspofungin exposure indicates that the absence of ShoA, MsbA, and OpyA affects the osmotic stress response, carbohydrate metabolism, and protein degradation. The putative receptor
mutants showed altered trehalose and glycogen accumulation, suggesting a role for
ShoA, MsbA, and OpyA in sugar storage. Protein kinase A activity was also decreased in these mutants. We also observed genetic interactions between SlnA,
ShoA, MsbA, and OpyA, suggesting that both branches are important for activation
of the HOG/CWI pathways. Our results help in the understanding of the activation
and modulation of the HOG and CWI pathways in this important fungal pathogen.São Paulo Research Foundation (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Irish Research CouncilScience Foundation Irelan
Downscaling the Gap: Protected Areas, Scientific Knowledge and the Conservation of Amphibian Species in Minas Gerais, Southeastern Brazil
Protected areas (PAs) cover a small proportion of the Earth's surface and most species are not covered by the current network. Amphibians are the least represented group in PAs around the world and expanding the network is still the major recommendation for species conservation. We evaluated the effectiveness of PAs in safeguarding endemic amphibians in the Cerrado biome of Minas Gerais state, southeastern Brazil. We conducted a gap analysis to highlight site-based conservation actions for target species within study site. We extracted occurrence points from the national database and calculated the intersection between the minimum convex polygon and natural vegetation remnants for each species. For each target species, we calculated the percentage of the range covered by PAs and assessed the scientific knowledge based on academic publications between 1950–2015. We recorded 206 amphibians in Minas Gerais, of which 127 occur in the Cerrado. We identified 24 target species and concluded that 80% are insufficiently protected by the current PA network. A quarter of the species have zero coverage and most species have < 30% of their range legally protected. In southwestern Minas Gerais, we recommend habitat restoration and connectivity to provide additional habitat to target species. In western Minas Gerais, the creation of PA seems to be the best solution. The distribution of target species is concentrated in the Espinhaço Mountain Range, where we recommend the establishment of biodiversity corridors. We examined 246 publications, most of which focus on taxonomy. Few species have sufficient information to have their conservation status re-assessed, with only 26.8% of publications containing specific information on conservation. Scientific knowledge must be improved for all research areas, especially species distributions and ecology, to support evidence-based conservation and management actions
Molecular motors robustly drive active gels to a critically connected state
Living systems often exhibit internal driving: active, molecular processes
drive nonequilibrium phenomena such as metabolism or migration. Active gels
constitute a fascinating class of internally driven matter, where molecular
motors exert localized stresses inside polymer networks. There is evidence that
network crosslinking is required to allow motors to induce macroscopic
contraction. Yet a quantitative understanding of how network connectivity
enables contraction is lacking. Here we show experimentally that myosin motors
contract crosslinked actin polymer networks to clusters with a scale-free size
distribution. This critical behavior occurs over an unexpectedly broad range of
crosslink concentrations. To understand this robustness, we develop a
quantitative model of contractile networks that takes into account network
restructuring: motors reduce connectivity by forcing crosslinks to unbind.
Paradoxically, to coordinate global contractions, motor activity should be low.
Otherwise, motors drive initially well-connected networks to a critical state
where ruptures form across the entire network.Comment: Main text: 21 pages, 5 figures. Supplementary Information: 13 pages,
8 figure
Biofilter aquaponic system for nutrients removal from fresh market wastewater
Aquaponics is a significant wastewater treatment system which refers to the combination of conventional aquaculture (raising aquatic organism) with hydroponics (cultivating plants in water) in a symbiotic environment. This system has a high ability in removing nutrients compared to conventional methods because it is a natural and environmentally friendly system (aquaponics). The current chapter aimed to review the possible application of aquaponics system to treat fresh market wastewater with the intention to highlight the mechanism of phytoremediation occurs in aquaponic system. The literature revealed that aquaponic system was able to remove nutrients in terms of nitrogen and phosphorus
Cosmology of the selfaccelerating third order Galileon
In this paper we start from the original formulation of the galileon model
with the original choice for couplings to gravity. Within this framework we
find that there is still a subset of possible Lagrangians that give
selfaccelerating solutions with stable spherically symmetric solutions. This is
a certain constrained subset of the third order galileon which has not been
explored before. We develop and explore the background cosmological evolution
of this model drawing intuition from other even more restricted galileon
models. The numerical results confirm the presence of selfacceleration, but
also reveals a possible instability with respect to galileon perturbations.Comment: 30 pages, 24 figure
Forensic dentistry now and in the future
Forensic dentistry (odontology) deals with the examination, handling and presentation of dental evidence for the legal system. In the UK this work mainly involves criminal cases but in many other countries its remit also extends to civil litigation. There are four main aspects to forensic dentistry: single body identification, Disaster Victim Identification (DVI), age estimation and bite mark identification and analysis. This article provides a brief introduction to the topics and discusses potential future developments that aim to reduce the subjectivity in the analysis process and simplify presentation of evidence to non-dental parties.
CPD/Clinical Relevance: This article highlights ways that dental practitioners can assist legal investigations and, in particular, forensic dentists
The effectiveness of public health interventions to reduce the health impact of climate change:a systematic review of systematic reviews
Climate change is likely to be one of the most important threats to public health in the coming years. Yet despite the large number of papers considering the health impact of climate change, few have considered what public health interventions may be of most value in reducing the disease burden. We aimed to evaluate the effectiveness of public health interventions to reduce the disease burden of high priority climate sensitive diseases
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