Freshwater waterways, and species that depend on them, are threatened by urbanisation and the consequences of the urban stream syndrome. In south-east Queensland, Australia, little is known about the impacts of the urban stream syndrome on the platypus (), meaning that populations cannot be adequately managed by conservation practitioners. The aim of this study was to determine how habitat and environmental variables, related to the urban stream syndrome, influenced platypus distribution across this region.
View Article and Find Full Text PDFPolymerase Chain Reaction (PCR) requires thermal cycling to melt DNA and proceed through the subsequent cycles of DNA synthesis needed for exponential amplification. Previously, we engineered a superhelicase, with enhanced processivity and speed, to replace this traditional PCR melting step with enzymatic DNA unwinding while retaining desired PCR characteristics, such as multi-kb amplicon size and applicability to cloning and gene editing outcome assessment. This isothermal amplification method is named SHARP (SSB-Helicase Assisted Rapid PCR) because single-stranded DNA binding protein (SSB) and superhelicases are added to standard PCR reagents.
View Article and Find Full Text PDFSpiders have important ecological roles as generalist predators, are a significant source of food for many other species, and are bioindicators of environmental health. However, spiders are poorly studied. Given their importance, a comparison of spider survey methods used to determine differences in spider diversity and abundance is required to understand their limitations and biases.
View Article and Find Full Text PDFTargeted protein degradation (TPD) modulates protein function beyond inhibition of enzyme activity or protein-protein interactions. Most degraders function by proximity induction, and directly bridge an E3 ligase with the target to be degraded. However, many proteins might not be addressable via proximity-based degraders, and other challenges, such as resistance acquisition, exist.
View Article and Find Full Text PDFWe explored the ecological and historical factors that led to formation of the unique guild of native and introduced mammalian herbivores between 5 and 1000 kg in northern Australia. Following the disappearance of large native herbivores about 46 kya, and until the arrival of Europeans and their livestock, the only herbivorous mammals were mid-sized endemic marsupial macropods, which continued to utilise the same vegetation as their much larger former neighbours. Only one species of contemporary native herbivore has an adult bodyweight approaching 100 kg, and for the past 150-200 years, the total biomass of introduced domestic and wild vertebrate herbivores has massively exceeded that of native herbivorous species.
View Article and Find Full Text PDFThe yeast glucose-induced degradation-deficient (GID) E3 ubiquitin ligase forms a suite of complexes with interchangeable receptors that selectively recruit N-terminal degron motifs of metabolic enzyme substrates. The orthologous higher eukaryotic C-terminal to LisH (CTLH) E3 complex has been proposed to also recognize substrates through an alternative subunit, WDR26, which promotes the formation of supramolecular CTLH E3 assemblies. Here, we discover that human WDR26 binds the metabolic enzyme nicotinamide/nicotinic-acid-mononucleotide-adenylyltransferase 1 (NMNAT1) and mediates its CTLH E3-dependent ubiquitylation independently of canonical GID/CTLH E3-family substrate receptors.
View Article and Find Full Text PDFPatients with Skraban-Deardorff syndrome (SKDEAS), a neurodevelopmental syndrome associated with a spectrum of developmental and intellectual delays and disabilities, harbor diverse mutations in WDR26, encoding a subunit of the multiprotein CTLH E3 ubiquitin ligase complex. Structural studies revealed that homodimers of WDR26 bridge two core-CTLH E3 complexes to generate giant, hollow oval-shaped supramolecular CTLH E3 assemblies. Additionally, WDR26 mediates CTLH E3 complex binding to subunit YPEL5 and functions as substrate receptor for the transcriptional repressor HBP1.
View Article and Find Full Text PDFNeuroblastoma with MYCN amplification (MNA) is a high-risk disease that has a poor survival rate. Neuroblastoma displays cellular heterogeneity, including more differentiated (adrenergic) and more primitive (mesenchymal) cellular states. Here, we demonstrate that MYCN oncoprotein promotes a cellular state switch in mesenchymal cells to an adrenergic state, accompanied by induction of histone lysine demethylase 4 family members (KDM4A-C) that act in concert to control the expression of MYCN and adrenergic core regulatory circulatory (CRC) transcription factors.
View Article and Find Full Text PDFGenomes are self-organized and self-maintained as long, complex macromolecules of chromatin. The inherent heterogeneity, stochasticity, phase separation, and chromatin dynamics of genome operation make it challenging to study genomes using ensemble methods. Various single-molecule force-, fluorescent-, and sequencing-based techniques rooted in different disciplines have been developed to fill critical gaps in the capabilities of bulk measurements, each providing unique, otherwise inaccessible, insights into the structure and maintenance of the genome.
View Article and Find Full Text PDFTransmembrane E3 ligases play crucial roles in homeostasis. Much protein and organelle quality control, and metabolic regulation, are determined by ER-resident MARCH6 E3 ligases, including Doa10 in yeast. Here, we present Doa10/MARCH6 structural analysis by cryo-EM and AlphaFold predictions, and a structure-based mutagenesis campaign.
View Article and Find Full Text PDFThe cullin-RING ubiquitin ligase (CRL) network comprises over 300 unique complexes that switch from inactive to activated conformations upon site-specific cullin modification by the ubiquitin-like protein NEDD8. Assessing cellular repertoires of activated CRL complexes is critical for understanding eukaryotic regulation. However, probes surveying networks controlled by site-specific ubiquitin-like protein modifications are lacking.
View Article and Find Full Text PDFAlveolar macrophages (alvMs) play an important role for maintenance of lung function by constant removal of cellular debris in the alveolar space. They further contribute to defense against microbial or viral infections and limit tissue damage during acute lung injury. alvMs arise from embryonic progenitor cells, seed the alveoli before birth, and have life-long self-renewing capacity.
View Article and Find Full Text PDFRegulated tryptophan metabolism by immune cells has been associated with the promotion of tolerance and poor outcomes in cancer. The main focus of research has centered on local tryptophan depletion by IDO1, an intracellular heme-dependent oxidase that converts tryptophan to formyl-kynurenine. This is the first step of a complex pathway supplying metabolites for de novo NAD biosynthesis, 1-carbon metabolism, and a myriad of kynurenine derivatives of which several act as agonists of the arylhydrocarbon receptor (AhR).
View Article and Find Full Text PDFHuman-dominated landscapes provide heterogeneous wildlife habitat. Conservation of habitat specialists, like red pandas , inhabiting such landscapes is challenging. Therefore, information on resource use across spatial and temporal scales could enable informed-decision making with better conservation outcomes.
View Article and Find Full Text PDFThe cullin-RING E3 ligase (CRL) network comprises over 300 unique complexes that switch from inactive to activated conformations upon site-specific cullin modification by the ubiquitin-like protein NEDD8. Assessing cellular repertoires of activated CRL complexes is critical for understanding eukaryotic regulation. However, probes surveying networks controlled by site-specific ubiquitin-like protein modifications are lacking.
View Article and Find Full Text PDFInfection with the intracellular bacterium Coxiella (C.) burnetii can cause chronic Q fever with severe complications and limited treatment options. Here, we identify the enzyme cis-aconitate decarboxylase 1 (ACOD1 or IRG1) and its product itaconate as protective host immune pathway in Q fever.
View Article and Find Full Text PDFThe development of haematopoietic stem cells into mature erythrocytes - erythropoiesis - is a controlled process characterized by cellular reorganization and drastic reshaping of the proteome landscape. Failure of ordered erythropoiesis is associated with anaemias and haematological malignancies. Although the ubiquitin system is a known crucial post-translational regulator in erythropoiesis, how the erythrocyte is reshaped by the ubiquitin system is poorly understood.
View Article and Find Full Text PDFProgressive accrual of senescent cells in aging and chronic diseases is associated with detrimental effects in tissue homeostasis. We found that senescent fibroblasts and epithelia were not only refractory to macrophage-mediated engulfment and removal, but they also paralyzed the ability of macrophages to remove bystander apoptotic corpses. Senescent cell-mediated efferocytosis suppression (SCES) was independent of the senescence-associated secretory phenotype (SASP) but instead required direct contact between macrophages and senescent cells.
View Article and Find Full Text PDFmTORC1 and GCN2 are serine/threonine kinases that control how cells adapt to amino acid availability. mTORC1 responds to amino acids to promote translation and cell growth while GCN2 senses limiting amino acids to hinder translation via eIF2α phosphorylation. GCN2 is an appealing target for cancer therapies because malignant cells can harness the GCN2 pathway to temper the rate of translation during rapid amino acid consumption.
View Article and Find Full Text PDFProfibrotic and prohomeostatic macrophage phenotypes remain ill-defined, both and , impeding the successful development of drugs that reprogram macrophages as an attractive therapeutic approach to manage fibrotic disease. The goal of this study was to reveal profibrotic and prohomeostatic macrophage phenotypes that could guide the design of new therapeutic approaches targeting macrophages to treat fibrotic disease. This study used nintedanib, a broad kinase inhibitor approved for idiopathic pulmonary fibrosis, to dissect lung macrophage phenotypes during fibrosis-linked inflammation by combining and bulk and single-cell RNA-sequencing approaches.
View Article and Find Full Text PDFSuccessful subunit vaccination with recombinant proteins requires adjuvants. The glycolipid trehalose-dibehenate (TDB), a synthetic analog of the mycobacterial cord factor, potently induces Th1 and Th17 immune responses and is a candidate adjuvant for human immunization. TDB binds to the C-type lectin receptor Mincle and triggers Syk-Card9-dependent APC activation.
View Article and Find Full Text PDFKoalas are facing many threats and have now been officially listed as endangered. Recently, concerns were raised in anecdotal reports of koalas being killed by livestock, especially cattle. We investigated the significance of cattle as a threat to koala survival via two koala-cattle interaction experiments, from both the koala and cattle perspectives.
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