A5008377267- Genetic Neurodegenerative Diseases
- Mitochondrial Function and Pathology
- Protein Structure and Dynamics
- Alzheimer's disease research and treatments
- Endoplasmic Reticulum Stress and Disease
- Amyotrophic Lateral Sclerosis Research
- RNA Research and Splicing
- Ubiquitin and proteasome pathways
- Heat shock proteins research
- Prion Diseases and Protein Misfolding
- Enzyme Structure and Function
- Diabetes, Cardiovascular Risks, and Lipoproteins
- Advanced Proteomics Techniques and Applications
- Lipoproteins and Cardiovascular Health
- Fungal and yeast genetics research
- Autophagy in Disease and Therapy
- Cellular transport and secretion
- RNA and protein synthesis mechanisms
- Parkinson's Disease Mechanisms and Treatments
- Metabolomics and Mass Spectrometry Studies
- Mass Spectrometry Techniques and Applications
- Click Chemistry and Applications
- Metabolism and Genetic Disorders
- Biotin and Related Studies
- Protein Interaction Studies and Fluorescence Analysis
The University of Melbourne
2015-2024
Biotechnology Institute
2011-2022
Gladstone Institutes
2002-2012
Mental Health Research Institute
2009-2010
In-Q-Tel
2008
University of California, San Francisco
2005-2006
Cardiovascular Institute Hospital
2005
Health Sciences and Nutrition
2002
Commonwealth Scientific and Industrial Research Organisation
2002
University of Oxford
2000
Prion-like domains (PLDs) are low complexity sequences found in RNA binding proteins associated with the neurodegenerative disorder amyotrophic lateral sclerosis. Recently, PLDs have been implicated mediating gene regulation via liquid-phase transitions that drive ribonucleoprotein granule assembly. In this paper, we report many paraspeckles, subnuclear bodies form around long noncoding RNA. We mapped interactome network of paraspeckle proteins, finding enrichment PLDs. show one protein,...
Aberrant phase separation of globular proteins is associated with many diseases. Here, we use a model protein system to understand how the unfolded states drive and formation deposits (UPODs). We find that for UPODs form, concentrations molecules must be above threshold value. Additionally, possess appropriate sequence grammars separation. While recruit molecular chaperones, their compositional profiles are also influenced by synergistic physicochemical interactions governed cellular...
Human apolipoprotein C-II (apoC-II) slowly forms amyloid fibers in lipid-free solutions at physiological pH and salt concentrations (Hatters, D. M., MacPhee, C. E., Lawrence, L. J., Sawyer, W. H., Howlett, G. J. (2000) Biochemistry 39, 8276--8283). Measurements of the time dependence solution turbidity, thioflavin T reactivity, amount sedimentable aggregate reveal that rate extent formation are significantly increased by addition an inert polymer, dextran T10, exceeding 20 g/liter. High do...
The amino-terminal domain of apolipoprotein (apo) E4 is less susceptible to chemical and thermal denaturation than the apoE3 apoE2 domains. We compared urea curves 22-kDa domains apoE isoforms at pH 7.4 4.0. At 7.4, apoE4 reflected an apparent two-state denaturation. midpoints were 5.2 4.3 m urea, respectively. 4.0, a value known stabilize folding intermediates, displayed same order but with distinct plateaus, suggesting presence stable intermediate. In contrast, proved most lacked plateau...
When proteostasis becomes unbalanced, unfolded proteins can accumulate and aggregate. Here we report that the dye, tetraphenylethene maleimide (TPE-MI) be used to measure cellular protein load. TPE-MI fluorescence is activated upon labelling free cysteine thiols, normally buried in core of globular are exposed unfolding. Crucially does not become fluorescent when conjugated soluble glutathione. We find enhanced reaction with proteomes under conditions promoting accumulation proteins....
Huntington disease is caused by expanded polyglutamine sequences in huntingtin, which procures its aggregation into intracellular inclusion bodies (IBs). Aggregate intermediates, such as soluble oligomers, are predicted to be toxic cells, yet because of a lack quantitative methods, the kinetics cells remains poorly understood. We used sedimentation velocity analysis define and compare heterogeneity flux purified huntingtin with expressed mammalian under non-denaturing conditions....
Abstract Amyotrophic lateral sclerosis is a rapidly progressing neurodegenerative disease associated with protein misfolding and aggregation. Most cases are characterized by TDP-43 positive inclusions, while minority of familial ALS instead FUS SOD1 respectively. Cells can generate inclusions variable type including previously aggresomes, IPOD or JUNQ structures depending on the misfolded protein. invariably forms but it remains unclear whether other aggregates arise as one these described...
Competing models exist in the literature for relationship between mutant Huntingtin exon 1 (Httex1) inclusion formation and toxicity. In one, inclusions are adaptive by sequestering proteotoxicity of soluble Httex1. other, compromise cellular activity as a result proteome co-aggregation. Using biosensor Httex1 conformation mammalian cell models, we discovered mechanism that reconciles these competing models. Newly formed were composed disordered ribonucleoproteins. As matured, reconfigured...
Low protein synthesis is a feature of somatic stem cells that promotes regeneration in multiple tissues. Modest increases impair cell function, but the mechanisms by which this occurs are largely unknown. We determine low within hematopoietic (HSCs) associated with elevated proteome quality vivo. HSCs contain less misfolded and unfolded proteins than myeloid progenitors. Increases cause to accumulate proteins. To test how affects HSCs, we examine Aarssti/sti mice harbor tRNA editing defect...
The self-association of proteins to form amyloid fibrils has been implicated in the pathogenesis a number diseases including Alzheimer's, Parkinson's, and Creutzfeldt-Jakob diseases. We recently reported that myeloid scavenger receptor CD36 initiates signaling cascade upon binding fibrillar β-amyloid stimulates recruitment microglia brain production inflammatory mediators. This plays key role atherosclerosis, prompting us evaluate whether were present atherosclerotic lesions could initiate...
Amyotrophic Lateral Sclerosis is characterized by a focal onset of symptoms followed progressive spread pathology that has been likened to transmission infectious prions. Cell-to-cell SOD1 protein aggregates dependent on fluid-phase endocytosis pathways, although the precise molecular mechanisms remain be elucidated. We demonstrate in this paper interact with cell surface triggering activation Rac1 and subsequent membrane ruffling permitting aggregate uptake via stimulated macropinocytosis....
Soluble huntingtin exon 1 (Httex1) with expanded polyglutamine (polyQ) engenders neurotoxicity in Huntington's disease. To uncover the physical basis of this toxicity, we performed structural studies soluble Httex1 for wild-type and mutant polyQ lengths. Nuclear magnetic resonance experiments show evidence conformational rigidity across region. In contrast, hydrogen-deuterium exchange shows absence backbone amide protection, suggesting negligible persistence hydrogen bonds. The seemingly...
The accumulation of protein deposits in neurodegenerative diseases has been hypothesized to depend on a metastable subproteome vulnerable aggregation. To investigate this phenomenon and the mechanisms that regulate it, we measured solubility proteome mouse Neuro2a cell line under six different homeostasis stresses: 1) Huntington's disease proteotoxicity, 2) Hsp70, 3) Hsp90, 4) proteasome, 5) endoplasmic reticulum (ER)-mediated folding inhibition, 6) oxidative stress. Overall, found about...
Human apolipoprotein C-II (apoC-II) self-associates in solution to form aggregates with the characteristics of amyloid including red-green birefringence presence Congo Red under cross-polarized light, increased fluorescence thioflavin T, and a fibrous structure when examined by electron microscopy. ApoC-II was expressed purified from Escherichia coli rapidly exchanged 5 M guanidine hydrochloride into 100 mM sodium phosphate, pH 7.4, final concentration 0.3 mg/mL. This apoC-II initially...
Under lipid-free conditions, human apolipoprotein C-II (apoC-II) exists in an unfolded conformation that over several days forms amyloid ribbons. We examined the influence of molecular chaperone, α-crystallin, on formation by apoC-II. Time-dependent changes apoC-II turbidity (at 0.3 mg/ml) were suppressed potently substoichiometric subunit concentrations α-crystallin (1–10 μg/ml). α-Crystallin also inhibits time-dependent CD spectra, thioflavin T binding, and sedimentation coefficient This...
Apolipoprotein (apo)E plays a critical role in cholesterol transport, through high affinity binding to the low density lipoprotein receptor. This interaction requires apoE be associated with particle. To determine structure of biologically active on particle, we crystallized dipalmitoylphosphatidylcholine particles containing two molecules and determined molecular envelope at 10 Å resolution. On basis supporting biochemical evidence, propose model which each molecule is folded into helical...