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1.
bioRxiv ; 2023 May 08.
Article in English | MEDLINE | ID: mdl-37214873

ABSTRACT

Dopa-responsive dystonia (DRD) and Parkinson's disease (PD) are movement disorders caused by the dysfunction of nigrostriatal dopaminergic neurons. Identifying druggable pathways and biomarkers for guiding therapies is crucial due to the debilitating nature of these disorders. Recent genetic studies have identified variants of GTP cyclohydrolase-1 (GCH1), the rate-limiting enzyme in tetrahydrobiopterin (BH4) synthesis, as causative for these movement disorders. Here, we show that genetic and pharmacological inhibition of BH4 synthesis in mice and human midbrain-like organoids accurately recapitulates motor, behavioral and biochemical characteristics of these human diseases, with severity of the phenotype correlating with extent of BH4 deficiency. We also show that BH4 deficiency increases sensitivities to several PD-related stressors in mice and PD human cells, resulting in worse behavioral and physiological outcomes. Conversely, genetic and pharmacological augmentation of BH4 protects mice from genetically- and chemically induced PD-related stressors. Importantly, increasing BH4 levels also protects primary cells from PD-affected individuals and human midbrain-like organoids (hMLOs) from these stressors. Mechanistically, BH4 not only serves as an essential cofactor for dopamine synthesis, but also independently regulates tyrosine hydroxylase levels, protects against ferroptosis, scavenges mitochondrial ROS, maintains neuronal excitability and promotes mitochondrial ATP production, thereby enhancing mitochondrial fitness and cellular respiration in multiple preclinical PD animal models, human dopaminergic midbrain-like organoids and primary cells from PD-affected individuals. Our findings pinpoint the BH4 pathway as a key metabolic program at the intersection of multiple protective mechanisms for the health and function of midbrain dopaminergic neurons, identifying it as a potential therapeutic target for PD.

2.
Lung ; 201(2): 171-179, 2023 04.
Article in English | MEDLINE | ID: mdl-37009923

ABSTRACT

Respiratory tract infection (RTI) remains a significant cause of morbidity and mortality across the globe. The optimal management of RTI relies upon timely pathogen identification via evaluation of respiratory samples, a process which utilises traditional culture-based methods to identify offending microorganisms. This process can be slow and often prolongs the use of broad-spectrum antimicrobial therapy, whilst also delaying the introduction of targeted therapy as a result. Nanopore sequencing (NPS) of respiratory samples has recently emerged as a potential diagnostic tool in RTI. NPS can identify pathogens and antimicrobial resistance profiles with greater speed and efficiency than traditional sputum culture-based methods. Increased speed to pathogen identification can improve antimicrobial stewardship by reducing the use of broad-spectrum antibiotic therapy, as well as improving overall clinical outcomes. This new technology is becoming more affordable and accessible, with some NPS platforms requiring minimal sample preparation and laboratory infrastructure. However, questions regarding clinical utility and how best to implement NPS technology within RTI diagnostic pathways remain unanswered. In this review, we introduce NPS as a technology and as a diagnostic tool in RTI in various settings, before discussing the advantages and limitations of NPS, and finally what the future might hold for NPS platforms in RTI diagnostics.


Subject(s)
Nanopore Sequencing , Nanopores , Respiratory Tract Infections , Humans , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/drug therapy , Anti-Bacterial Agents/therapeutic use , Metagenomics/methods
4.
PLoS One ; 18(1): e0280364, 2023.
Article in English | MEDLINE | ID: mdl-36649303

ABSTRACT

The immune system plays a central role in the onset and progression of cancer. A better understanding of transcriptional changes in immune cell-related genes associated with cancer progression, and their significance in disease prognosis, is therefore needed. NanoString-based targeted gene expression profiling has advantages for deployment in a clinical setting over RNA-seq technologies. We analysed NanoString PanCancer Immune Profiling panel gene expression data encompassing 770 genes, and overall survival data, from multiple previous studies covering 10 different cancer types, including solid and blood malignancies, across 515 patients. This analysis revealed an immune gene signature comprising 39 genes that were upregulated in those patients with shorter overall survival; of these 39 genes, three (MAGEC2, SSX1 and ULBP2) were common to both solid and blood malignancies. Most of the genes identified have previously been reported as relevant in one or more cancer types. Using Cibersort, we investigated immune cell levels within individual cancer types and across groups of cancers, as well as in shorter and longer overall survival groups. Patients with shorter survival had a higher proportion of M2 macrophages and γδ T cells. Patients with longer overall survival had a higher proportion of CD8+ T cells, CD4+ T memory cells, NK cells and, unexpectedly, T regulatory cells. Using a transcriptomics platform with certain advantages for deployment in a clinical setting, our multi-cancer meta-analysis of immune gene expression and overall survival data has identified a specific transcriptional profile associated with poor overall survival.


Subject(s)
Neoplasms , Transcriptome , Humans , Neoplasms/genetics , Gene Expression Profiling , Prognosis , CD4-Positive T-Lymphocytes
5.
ERJ Open Res ; 8(4)2022 Oct.
Article in English | MEDLINE | ID: mdl-36545212

ABSTRACT

This correspondence highlights the burden of respiratory tract infection and focuses on nanopore sequencing as a promising approach in diagnostics https://bit.ly/3fgs8zg.

6.
Biochem Biophys Rep ; 32: 101365, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36237445

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is commonly diagnosed at a late stage and becomes resistant to several treatments. Significant clinical effects have been reported for cancer immunotherapies on a subset of patients diagnosed with epithelial cancers. Cancer organoid co-culture with autologous peripheral blood lymphocytes offers an innovative immunotherapeutic approach that is increasingly being tested, although there is a lack of cutting-edge platforms enabling the investigation of cancer-T cell interactions for individual patients. In this study, a pancreatic cancer organoid culture from a genetically engineered pancreatic cancer murine model was established and co-cultured with autologous peripheral blood lymphocytes to induce a tumour-specific T cell response to pancreatic cancer. Co-culturing autologous peripheral blood lymphocytes with cancer organoids can be an effective strategy to enrich tumour-reactive T cells from the peripheral blood of murine models; this approach could potentially be transferred to humans. Co-culture of peripheral blood lymphocytes and cancer organoids could provide an unbiased approach to evaluating the sensitivity of tumour cells to T cell-mediated priming on an individual patient level.

7.
Microb Genom ; 8(2)2022 02.
Article in English | MEDLINE | ID: mdl-35143385

ABSTRACT

Bacterial genetic diversity is often described solely using base-pair changes despite a wide variety of other mutation types likely being major contributors. Tandem duplication/amplifications are thought to be widespread among bacteria but due to their often-intractable size and instability, comprehensive studies of these mutations are rare. We define a methodology to investigate amplifications in bacterial genomes based on read depth of genome sequence data as a proxy for copy number. We demonstrate the approach with Bordetella pertussis, whose insertion sequence element-rich genome provides extensive scope for amplifications to occur. Analysis of data for 2430 B. pertussis isolates identified 272 putative amplifications, of which 94 % were located at 11 hotspot loci. We demonstrate limited phylogenetic connection for the occurrence of amplifications, suggesting unstable and sporadic characteristics. Genome instability was further described in vitro using long-read sequencing via the Nanopore platform, which revealed that clonally derived laboratory cultures produced heterogenous populations rapidly. We extended this research to analyse a population of 1000 isolates of another important pathogen, Mycobacterium tuberculosis. We found 590 amplifications in M. tuberculosis, and like B. pertussis, these occurred primarily at hotspots. Genes amplified in B. pertussis include those involved in motility and respiration, whilst in M. tuberuclosis, functions included intracellular growth and regulation of virulence. Using publicly available short-read data we predicted previously unrecognized, large amplifications in B. pertussis and M. tuberculosis. This reveals the unrecognized and dynamic genetic diversity of B. pertussis and M. tuberculosis, highlighting the need for a more holistic understanding of bacterial genetics.


Subject(s)
Bordetella pertussis/genetics , Genetic Variation , Mycobacterium tuberculosis/genetics , Bordetella pertussis/classification , Genes, Bacterial/genetics , Genome, Bacterial , Genomic Instability , Mutation , Mycobacterium tuberculosis/classification , Phylogeny , Virulence/genetics , Whooping Cough/microbiology
8.
Microb Genom ; 8(1)2022 01.
Article in English | MEDLINE | ID: mdl-35084300

ABSTRACT

Whooping cough, the respiratory disease caused by Bordetella pertussis, has undergone a wide-spread resurgence over the last several decades. Previously, we developed a pipeline to assemble the repetitive B. pertussis genome into closed sequences using hybrid nanopore and Illumina sequencing. Here, this sequencing pipeline was used to conduct a more high-throughput, longitudinal screen of 66 strains isolated between 1982 and 2018 in New Zealand. New Zealand has a higher incidence of whooping cough than many other countries; usually at least twice as many cases per 100000 people as the USA and UK and often even higher, despite similar rates of vaccine uptake. To the best of our knowledge, these strains are the first New Zealand B. pertussis isolates to be sequenced. The analyses here show that, on the whole, genomic trends in New Zealand B. pertussis isolates, such as changing allelic profile in vaccine-related genes and increasing pertactin deficiency, have paralleled those seen elsewhere in the world. At the same time, phylogenetic comparisons of the New Zealand isolates with global isolates suggest that a number of strains are circulating in New Zealand, which cluster separately from other global strains, but which are closely related to each other. The results of this study add to a growing body of knowledge regarding recent changes to the B. pertussis genome, and are the first genetic investigation into B. pertussis isolates from New Zealand.


Subject(s)
Bordetella pertussis/classification , Genomics/methods , Whole Genome Sequencing/methods , Whooping Cough/epidemiology , Bordetella pertussis/genetics , Bordetella pertussis/isolation & purification , Genome, Bacterial , High-Throughput Nucleotide Sequencing , Humans , Incidence , Nanopore Sequencing , New Zealand/epidemiology , Phylogeny
9.
J Thromb Haemost ; 20(3): 729-741, 2022 03.
Article in English | MEDLINE | ID: mdl-34846792

ABSTRACT

AIMS: P-selectin is a key surface adhesion molecule for the interaction of platelets with leukocytes. We have shown previously that the N-terminal domain of Staphylococcus aureus extracellular fibrinogen-binding protein (Efb) binds to P-selectin and interferes with platelet-leukocyte aggregate formation. Here, we aimed to identify the minimal Efb motif required for binding platelets and to characterize its ability to interfering with the formation of platelet-leukocyte aggregates. METHODS AND RESULTS: Using a library of synthetic peptides, we mapped the platelet-binding site to a continuous 20 amino acid stretch. The peptide Efb68-87 was able to bind to resting and, to a greater extent, thrombin-stimulated platelets in the absence of fibrinogen. Dot blots, pull-down assays and P-selectin glycoprotein ligand-1 (PSGL-1) competitive binding experiments identified P-selectin as the cellular docking site mediating Efb68-87 platelet binding. Accordingly, Efb68-87 did not bind to other blood cells and captured platelets from human whole blood under low shear stress conditions. Efb68-87 did not affect platelet activation as tested by aggregometry, flow cytometry and immunoblotting, but inhibited the formation of platelet-leukocyte aggregates (PLAs). Efb68-87 also interfered with the platelet-dependent stimulation of neutrophil extracellular traps (NETs) formation in vitro. CONCLUSIONS: We have identified Efb68-87 as a novel selective platelet-binding peptide. Efb68-87 binds directly to P-selectin and inhibits interactions of platelets with leukocytes that lead to PLA and NET formation. As PLAs and NETs play a key role in thromboinflammation, Efb68-87 is an exciting candidate for the development of novel selective inhibitors of the proinflammatory activity of platelets.


Subject(s)
P-Selectin , Thrombosis , Blood Platelets/metabolism , Fibrinogen/metabolism , Humans , Inflammation/metabolism , Leukocytes/metabolism , P-Selectin/metabolism , Peptides/metabolism , Platelet Activation , Thrombosis/metabolism
10.
Cancers (Basel) ; 12(11)2020 Nov 06.
Article in English | MEDLINE | ID: mdl-33172113

ABSTRACT

The treatment of patients affected by non-small cell lung cancer (NSCLC) has been revolutionised by the discovery of druggable mutations. ROS1 (c-ros oncogene) is one gene with druggable mutations in NSCLC. ROS1 is currently targeted by several specific tyrosine kinase inhibitors (TKIs), but only two of these, crizotinib and entrectinib, have received Food and Drug Administration (FDA) approval. Crizotinib is a low molecular weight, orally available TKI that inhibits ROS1, MET and ALK and is considered the gold standard first-line treatment with demonstrated significant activity for lung cancers harbouring ROS1 gene rearrangements. However, crizotinib resistance often occurs, making the treatment of ROS1-positive lung cancers more challenging. A great effort has been undertaken to identify a new generation or ROS1 inhibitors. In this review, we briefly introduce the biology and role of ROS1 in lung cancer and discuss the underlying acquired mechanisms of resistance to crizotinib and the promising new agents able to overcome resistance mechanisms and offer alternative efficient therapies.

11.
Curr Opin Rheumatol ; 32(6): 548-552, 2020 11.
Article in English | MEDLINE | ID: mdl-32890028

ABSTRACT

PURPOSE OF REVIEW: To provide an overview of recent discoveries related to myositis-specific autoantibodies (MSAs) and assays used for their measurement. RECENT FINDINGS: New autoantibody specificities have been reported including a MSA directed against eukaryotic initiation factor 3 and a myositis-associated autoantibody directed against heat shock factor 1. The association of anti-TIF1γ with cancer-associated dermatomyositis dependent on age has been confirmed in several large cohorts. Despite MSAs being almost entirely mutually exclusive, several myositis autoantigens are overexpressed in regenerating muscle and do not correlate with the corresponding MSA in any one patient. Further mechanisms may determine the final MSA specificity and are likely to include the need for autoantigen processing and presentation with adaptive T-cell help. The presence of CD4-positive T cells specific for histidyl tRNA synthetase protein in bronchial lavage fluid from antisynthetase patients lends support to this view. Finally, it is widely held that MSA do play an important role in clinical practice among some evidence and concern about commercial assay reliability. SUMMARY: MSAs continue to provide important tools for clinical diagnosis and management as well as insights into disease mechanisms. Further improvement in the standardization and reliability of routine detection of MSAs is a high priority.


Subject(s)
Autoantibodies/immunology , Autoantigens/immunology , Myositis/immunology , Humans , Reproducibility of Results
12.
Expert Rev Clin Pharmacol ; 13(10): 1139-1146, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32935605

ABSTRACT

INTRODUCTION: Erdafitinib is the first orally administered pan-fibroblast growth factor receptor (FGFR) kinase inhibitor approved by the Food and Drug Administration (FDA). AREAS COVERED: Specifically binding to FGFR family (FGFR-1 to FGFR-4), erdafitinib leads to reduced cell signaling and cellular apoptosis. Coupled with the ability to bind to vascular endothelial growth factor 2 (VEGFR-2), KIT, Fms-related tyrosine kinase 4 (FLT4), platelet-derived growth factor receptor α and ß (PDGFR-α and PDGFR-ß), RET and colony-stimulating factor 1 receptor (CSF-1 R), erdafitinib has further reported antitumor features causing cell killing. EXPERT OPINION: In this review, we provide a comprehensive overview of erdafitinib chemical structure, pharmacologic properties, and current knowledge of clinical efficacy in the treatment of locally advanced or metastatic urothelial carcinoma. This treatment, recently approved in the U.S., is available for adult patients harboring FGFR2/FGFR3 genetic alterations who progressed within 12 months of an adjuvant or neoadjuvant chemotherapy regimen including platinum or progressed during or after prior a chemotherapy regimen including platinum.


Subject(s)
Carcinoma, Transitional Cell/drug therapy , Pyrazoles/administration & dosage , Quinoxalines/administration & dosage , Urinary Bladder Neoplasms/drug therapy , Administration, Oral , Adult , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Carcinoma, Transitional Cell/pathology , Disease Progression , Humans , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Quinoxalines/pharmacology , Urinary Bladder Neoplasms/pathology
14.
Expert Rev Clin Pharmacol ; 13(6): 623-629, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32394749

ABSTRACT

INTRODUCTION: Hepatocellular carcinoma (HCC) is one of the most frequent tumors affecting the gastrointestinal tract and a universal cause of morbidity and mortality. Cabozantinib is a strong multi-inhibitor of receptor tyrosine kinases approved for renal cell carcinoma that could be useful also for the treatment of HCC. AREAS COVERED: This review describes the chemical structure, the pharmacologic properties and current knowledge of the efficacy of cabozantinib in the treatment of HCC based on data available from first phase and later phase clinical trials. The ongoing studies testing cabozantinib, either alone or in combination with other drugs, are also described. EXPERT OPINION: Despite the recent achievements in the use of cabozantinib for patients diagnosed with hepatocellular carcinoma, data are still needed to allow clinicians to make better decisions on how to treat specific patient subgroups.


Subject(s)
Anilides/administration & dosage , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Pyridines/administration & dosage , Anilides/pharmacology , Animals , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Carcinoma, Hepatocellular/pathology , Humans , Liver Neoplasms/pathology , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , Pyridines/pharmacology
15.
Crit Rev Oncol Hematol ; 149: 102921, 2020 May.
Article in English | MEDLINE | ID: mdl-32172222

ABSTRACT

Patients diagnosed with non-clear renal cell carcinoma have often been excluded from clinical trials due to the shortage of treatments available, the low incidence of tumours with non-clear histology, and the corresponding diversity of intrinsic molecular features. This approach led to a knowledge gap in finding the optimal treatment for patients diagnosed with non-clear cell renal carcinoma. Cabozantinib, a potent multiple tyrosine kinase receptor inhibitor, has been recently investigated in patients with non-clear cell histologies of renal cell cancer. In this review, we have summarized available data on the use of cabozantinib in non-clear renal cell carcinoma.


Subject(s)
Anilides/therapeutic use , Antibodies, Monoclonal/therapeutic use , Antineoplastic Agents/therapeutic use , Carcinoma, Renal Cell/drug therapy , Kidney Neoplasms/drug therapy , Pyridines/therapeutic use , Disease-Free Survival , Humans , Protein Kinase Inhibitors
16.
PLoS One ; 14(8): e0219566, 2019.
Article in English | MEDLINE | ID: mdl-31381571

ABSTRACT

BACKGROUND: We investigated the correlation between pancreatic ductal adenocarcinoma patient prognosis and the presence of tumour infiltrating lymphocytes and expression of 521 immune system genes. METHODS: Intratumoural CD3+, CD8+, and CD20+ lymphocytes were examined by immunohistochemistry in 12 PDAC patients with different outcomes who underwent pancreaticoduodenectomy. The results were correlated with gene expression profile using the digital multiplexed NanoString nCounter analysis system (NanoString Technologies, Seattle, WA, USA). RESULTS: Twenty immune system genes were significantly differentially expressed in patients with a good prognosis relative to patients with a worse prognosis: TLR2 and TLR7 (Toll-like receptor superfamily); CD4, CD37, FOXP3, PTPRC (B cell and T cell signalling); IRF5, IRF8, STAT1, TFE3 (transcription factors); ANP32B, CCND3 (cell cycle); BTK (B cell development); TNF, TNFRF1A (TNF superfamily); HCK (leukocyte function); C1QA (complement system); BAX, PNMA1 (apoptosis); IKBKE (NFκB pathway). Differential expression was more than twice log 2 for TLR7, TNF, C1QA, FOXP3, and CD37. DISCUSSION: Tumour infiltrating lymphocytes were present at higher levels in samples from patients with better prognosis. Our findings indicate that tumour infiltrating lymphocyte levels and expression level of the immune system genes listed above influence pancreatic ductal adenocarcinoma prognosis. This information could be used to improve selection of best responders to immune inhibitors.


Subject(s)
Adenocarcinoma/diagnosis , Adenocarcinoma/immunology , Lymphocytes, Tumor-Infiltrating/cytology , Pancreatic Neoplasms/diagnosis , Pancreatic Neoplasms/immunology , Transcriptome/immunology , Adenocarcinoma/genetics , Aged , Female , Humans , Male , Middle Aged , Pancreatic Neoplasms/genetics , Prognosis
17.
Adv Exp Med Biol ; 1183: 1-17, 2019.
Article in English | MEDLINE | ID: mdl-31321755

ABSTRACT

The evolution of Bordetella pertussis from a common ancestor similar to Bordetella bronchiseptica has occurred through large-scale gene loss, inactivation and rearrangements, largely driven by the spread of insertion sequence element repeats throughout the genome. B. pertussis is widely considered to be monomorphic, and recent evolution of the B. pertussis genome appears to, at least in part, be driven by vaccine-based selection. Given the recent global resurgence of whooping cough despite the wide-spread use of vaccination, a more thorough understanding of B. pertussis genomics could be highly informative. In this chapter we discuss the evolution of B. pertussis, including how vaccination is changing the circulating B. pertussis population at the gene-level, and how new sequencing technologies are revealing previously unknown levels of inter- and intra-strain variation at the genome-level.


Subject(s)
Bordetella pertussis/genetics , Genome, Bacterial , Pertussis Vaccine/administration & dosage , Whole Genome Sequencing , Whooping Cough/microbiology , Bordetella pertussis/drug effects , Genomics/methods , Humans , Phylogeny , Whooping Cough/immunology , Whooping Cough/prevention & control
18.
Microb Genom ; 4(11)2018 11.
Article in English | MEDLINE | ID: mdl-30461375

ABSTRACT

The genome of Bordetella pertussis is complex, with high G+C content and many repeats, each longer than 1000 bp. Long-read sequencing offers the opportunity to produce single-contig B. pertussis assemblies using sequencing reads which are longer than the repetitive sections, with the potential to reveal genomic features which were previously unobservable in multi-contig assemblies produced by short-read sequencing alone. We used an R9.4 MinION flow cell and barcoding to sequence five B. pertussis strains in a single sequencing run. We then trialled combinations of the many nanopore user community-built long-read analysis tools to establish the current optimal assembly pipeline for B. pertussis genome sequences. This pipeline produced closed genome sequences for four strains, allowing visualization of inter-strain genomic rearrangement. Read mapping to the Tohama I reference genome suggests that the remaining strain contains an ultra-long duplicated region (almost 200 kbp), which was not resolved by our pipeline; further investigation also revealed that a second strain that was seemingly resolved by our pipeline may contain an even longer duplication, albeit in a small subset of cells. We have therefore demonstrated the ability to resolve the structure of several B. pertussis strains per single barcoded nanopore flow cell, but the genomes with highest complexity (e.g. very large duplicated regions) remain only partially resolved using the standard library preparation and will require an alternative library preparation method. For full strain characterization, we recommend hybrid assembly of long and short reads together; for comparison of genome arrangement, assembly using long reads alone is sufficient.


Subject(s)
Bordetella pertussis/genetics , Genome, Bacterial , Sequence Analysis, DNA/methods , Molecular Sequence Annotation , Nanopores
19.
J Biol Chem ; 293(24): 9335-9344, 2018 06 15.
Article in English | MEDLINE | ID: mdl-29724824

ABSTRACT

Kidney- and brain-expressed protein (KIBRA), a multifunctional scaffold protein with around 20 known binding partners, is involved in memory and cognition, organ size control via the Hippo pathway, cell polarity, and membrane trafficking. KIBRA includes tandem N-terminal WW domains, a C2 domain, and motifs for binding atypical PKC and PDZ domains. A naturally occurring human KIBRA variant involving residue changes at positions 734 (Met-to-Ile) and 735 (Ser-to-Ala) within the C2 domain affects cognitive performance. We have elucidated 3D structures and calcium- and phosphoinositide-binding properties of human KIBRA C2 domain. Both WT and variant C2 adopt a canonical type I topology C2 domain fold. Neither Ca2+ nor any other metal ion was bound to WT or variant KIBRA C2 in crystal structures, and Ca2+ titration produced no significant reproducible changes in NMR spectra. NMR and X-ray diffraction data indicate that KIBRA C2 binds phosphoinositides via an atypical site involving ß-strands 5, 2, 1, and 8. Molecular dynamics simulations indicate that KIBRA C2 interacts with membranes via primary and secondary sites on the same domain face as the experimentally identified phosphoinositide-binding site. Our results indicate that KIBRA C2 domain association with membranes is calcium-independent and involves distinctive C2 domain-membrane relative orientations.


Subject(s)
Calcium/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Phosphatidylinositols/metabolism , Phosphoproteins/metabolism , C2 Domains , Cell Membrane/metabolism , Crystallography, X-Ray , Humans , Intracellular Signaling Peptides and Proteins/chemistry , Intracellular Signaling Peptides and Proteins/genetics , Models, Molecular , Phosphoproteins/chemistry , Phosphoproteins/genetics , Polymorphism, Single Nucleotide , Protein Binding , Protein Conformation
20.
ACS Appl Mater Interfaces ; 8(32): 21077-88, 2016 Aug 17.
Article in English | MEDLINE | ID: mdl-27447357

ABSTRACT

Developing generic strategies for building adaptable or multifunctional bioplatforms is challenging, in particular because protein immobilization onto surfaces often causes loss of protein function and because multifunctionality usually necessitates specific combinations of heterogeneous elements. Here, we introduce a generic, modular bioplatform construction strategy that uses cage-like supramolecular multienzyme complexes as highly adaptable building blocks immobilized directly and noncovalently on graphene. Thermoplasma acidophilum dihydrolipoyl acyltransferase (E2) supramolecular complexes organize as a monolayer or can be controllably transferred onto graphene, preserving their supramolecular form with specific molecular recognition capability and capacity for engineering multifunctionality. This E2-graphene platform can bind enzymes (here, E1, E2's physiological partner) without loss of enzyme function; in this test case, E1 catalytic activity was detected on E2-graphene over 6 orders of magnitude in substrate concentration. The E2-graphene platform can be multiplexed via patterned cotransfer of differently modified E2 complexes. As the E2 complexes are robust and highly customizable, E2-graphene is a platform onto which multiple functionalities can be built.


Subject(s)
Graphite/chemistry , Multienzyme Complexes , Proteins , Thermoplasma
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