174 research outputs found

    Photoaffinity cross-linking and unnatural amino acid mutagenesis reveal insights into calcitonin gene-related peptide binding to the calcitonin receptor-like receptor/receptor activity-modifying protein 1 (CLR/RAMP1) complex

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    Calcitonin gene-related peptide (CGRP) binds to the complex of the calcitonin receptor-like receptor (CLR) with receptor activity-modifying protein 1 (RAMP1). How CGRP interacts with the transmembrane domain (including the extracellular loops) of this family B receptor remains unclear. In this study, a photoaffinity cross-linker, p-azido l-phenylalanine (azF), was incorporated into CLR, chiefly in the second extracellular loop (ECL2) using genetic code expansion and unnatural amino acid mutagenesis. The method was optimized to ensure efficient photolysis of azF residues near the transmembrane bundle of the receptor. A CGRP analogue modified with fluorescein at position 15 was used for detection of ultraviolet-induced cross-linking. The methodology was verified by confirming the known contacts of CGRP to the extracellular domain of CLR. Within ECL2, the chief contacts were I284 on the loop itself and L291, at the top of the fifth transmembrane helix (TM5). Minor contacts were noted along the lip of ECL2 between S286 and L290 and also with M223 in TM3 and F349 in TM6. Full length molecular models of the bound receptor complex suggest that CGRP sits at the top of the TM bundle, with Thr6 of the peptide making contacts with L291 and H295. I284 is likely to contact Leu12 and Ala13 of CGRP, and Leu16 of CGRP is at the ECL/extracellular domain boundary of CLR. The reduced potency, Emax, and affinity of [Leu16Ala]-human α CGRP are consistent with this model. Contacts between Thr6 of CGRP and H295 may be particularly important for receptor activation

    Receptor activity-modifying proteins 2 and 3 generate adrenomedullin receptor subtypes with distinct molecular properties

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    Adrenomedullin (AM) is a peptide hormone with numerous effects in the vascular systems. AM signals through the AM1 and AM2 receptors formed by the obligate heterodimerization of a G protein-coupled receptor, the calcitonin receptor-like receptor (CLR), and receptor activity-modifying proteins (RAMP) 2 and 3, respectively. These different CLR-RAMP interactions yield discrete receptor pharmacology and physiological effects. The effective design of therapeutics that target the individual AM receptors is dependent on understanding the molecular details of the effects of RAMPs on CLR. To understand the role of RAMPs 2 and 3 on the activation and conformation of the CLR subunit of AM receptors we mutated 68 individual amino acids in the juxtamembrane region of CLR, a key region for activation of AM receptors and determined the effects on cAMP signalling. Sixteen CLR mutations had differential effects between the AM1 and AM2 receptors. Accompanying this, independent molecular modelling of the full-length AM-bound AM1 and AM2 receptors predicted differences in the binding pocket, and differences in the electrostatic potential of the two AM receptors. Druggability analysis indicated unique features that could be used to develop selective small molecule ligands for each receptor. The interaction of RAMP2 or RAMP3 with CLR induces conformational variation in the juxtamembrane region, yielding distinct binding pockets, probably via an allosteric mechanism. These subtype-specific differences have implications for the design of therapeutics aimed at specific AM receptors and for understanding the mechanisms by which accessory proteins affect G protein-coupled receptor function

    Limited Liability Companies in Kentucky, Second Edition

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    The Kentucky Limited Liability Company Act, KRS Chapter 275, went into effect July 15, 1994, allowing Kentuckians to conduct business under the LLC form. With over 10,000 LLCs formed in the Commonwealth since the Act\u27s inception, this flexible business entity has become the most popular way to conduct business in Kentucky. The LLC has become so pervasive that business law practitioners, accountants, tax advisors and estate planners must all be well-versed in the myriad of issues and creative applications that accompany this business entity. With flexible tax-treatment and the liability protection of a traditional corporation this entity is utilized not only for business formation and practice but also for business succession and estate planning, the structuring of joint ventures and strategic alliances, as venture capital vehicles, and as tax planning tools. The goal of this monograph is to provide the practitioner with a concise and comprehensive approach to the tools necessary for lawyers to counsel and advise clients on this complex and efficient business entity form. Succinct chapters take the reader through an overview of the LLC entity and the Kentucky LLC Act; choice of entity considerations (both tax and non-tax); the formation, operation and statutory transaction issues which arise for the entity; as well as the new single-member LLC; the professional LLC; the use of the LLC in tax-exempt organizations; wealth transfer planning with LLCs; and securities law, commercial law and benefit issues arising under the LLC entity. Each chapter is set forth in separately numbered paragraphs, present running headers for easy access, and are cross-referenced to other relevant chapters and paragraphs contained in the monograph. Summary and comparative charts, a table of authorities and a statutory appendix are also presented. Finally, a comprehensive index has been created to aid the user in finding relevant subject treatments

    Distinct Patterns of Internalization of Different Calcitonin GeneRelated Peptide Receptors

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    Calcitonin gene-related peptide (CGRP) is a neuropeptide that is involved in the transmission of pain. Drugs targeting CGRP or a CGRP receptor are efficacious in the treatment of migraine. The canonical CGRP receptor is a complex of a G protein-coupled receptor, the calcitonin-like receptor (CLR), with an accessory protein, receptor activity-modifying protein 1 (RAMP1). A second receptor, the AMY1 receptor, a complex of the calcitonin receptor with RAMP1, is a dual high-affinity receptor for CGRP and amylin. Receptor regulatory processes, such as internalization, are crucial for controlling peptide and drug responsiveness. Given the importance of CGRP receptor activity in migraine we compared the internalization profiles of both receptors for CGRP using novel fluorescent probes and a combination of live cell imaging, fixed cell imaging, and ELISA. This revealed stark differences in the regulation of each receptor with the AMY1 receptor unexpectedly showing little internalization.Peer Reviewe

    Oral steroids for the resolution of otitis media with effusion (OME) in children (OSTRICH): study protocol for a randomised controlled trial

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    Background Otitis media with effusion (OME) is an accumulation of fluid in the middle ear affecting about 80% of children by the age of 4 years. While OME usually resolves spontaneously, it can affect speech, behaviour and development. Children with persistent hearing loss associated with OME are usually offered hearing aids or insertion of ventilation tubes through the tympanic membrane. Oral steroids may be a safe and effective treatment for OME, which could be delivered in primary care. It has the potential to benefit large numbers of children and reduce the burden of care on them and on health services. However, previous trials have either been too small with too short a follow up period, or of too poor quality to give a definite answer. The aim of the OSTRICH trial is to determine if a short course of oral steroids improves the hearing of children with OME in the short and longer term. Methods/Design 380 participants (children aged 2-8 years) are recruited from Hospital Ear, Nose and Throat departments in Wales and England. A trained clinician seeks informed consent from parents of children with symptoms attributable to OME for at least 3 months and with confirmed bilateral hearing loss at study entry. Participants are randomised to a course of oral steroid or a matched placebo for one week. Outcomes include audiometry, tympanometry and otoscopy assessments, symptoms, adverse effects, functional health status, quality of life, resource use and cost effectiveness. Participants are followed up at 5 weeks, and at 6 and 12 months after the day of randomisation. The primary outcome is audiometry-confirmed satisfactory hearing at 5 weeks. Discussion There is an important evidence gap regarding clinical and cost effectiveness of short courses of oral steroid treatment for OME. Identifying an effective, safe, non-surgical intervention for OME in children for use in primary care would be of great benefit to children, their families and the NHS

    Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

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    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

    Human skeletal muscle is refractory to the anabolic effects of leucine during the postprandial muscle-full period in older men

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    Leucine modulates muscle protein synthesis (MPS), with potential to facilitate accrual/maintenance of muscle mass. Animal models suggest that leucine boluses shortly after meals may prolong MPS and delay onset of a “muscle-full” state. However, the effects of nutrient “top-ups” in humans, and particularly older adults where deficits exist, have not been explored. We determined the effects of a leucine top-up after essential amino acid (EAA) feeding on anabolic signaling, MPS, and muscle energy metabolism in older men. During 13C6-phenylalanine infusion, 16 men (∼70 years) consumed 15 g of EAA with (n=8, FED + LEU) or without (n=8, FED) 3 g of leucine top-up 90 min later. Repeated blood and muscle sampling permitted measurement of fasting and postprandial plasma EAA, insulin, anabolic signaling including mTOR complex 1 (mTORC1) substrates, cellular ATP and phosphorylocreatine, and MPS. Oral EAA achieved rapid insulinemia (12.5 iU·ml−1 25 min post-feed), essential aminoacidemia (3000 μM, 45–65 min post-feed), and activation of mTORC1 signaling. Leucine top-up prolonged plasma EAA (2800 μM, 135 min) and leucine availability (1050 μM, 135 min post-feed). Fasting FSRs of 0.046 and 0.056%·h-1 (FED and FED + LEU respectively) increased to 0.085 and 0.085%·h-1 90–180 min post-feed and returned to basal rates after 180 min in both groups. Phosphorylation of mTORC1 substrates returned to fasting levels 240 min post-feed in both groups. Feeding had limited effect on muscle elongation factor 2 (eEF2) phosphorylation. We demonstrate the refractoriness of muscle to nutrient-led anabolic stimulation in the postprandial period; thus, leucine supplements should be taken outside of meals, or with meals containing suboptimal protein in terms of either amount or EAA composition

    Crop Updates 2001 - Oilseeds

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    ABSTRACT This session covers twenty five papers from different authors: FORWARD, Mervyn McDougall, CHAIRMAN, PULSES AND OILSEEDS PARTNERSHIP GROUP PLENARY 1. Implications of the ‘green-bridge’ for viral and fungal disease carry-over between seasons, Debbie Thackray, Agriculture Western Australia and Centre for Legumes in Mediterranean Agriculture 2. Insect pest development in WA via the ‘green-bridge’, Kevin Walden, Agriculture Western Australia VARIETIES 3. Performance of new canola varieties in AGWEST variety trials, G. Walton, Crop Improvement Institute, Agriculture Western Australia 4. New herbicide tolerant varieties in WA, Kevin Morthorpe, Stephen Addenbrooke, Pioneer Hi-Bred Australia P/L 5. IT v’s TT – Head to head, Paul Carmody, Centre for Cropping Systems, Agriculture Western Australia ESTABLISHMENT 6. Effect of stubble, seeding technique and seed size on crop establishment and yield of canola, Rafiul Alam, Glen Riethmuller and Greg Hamilton, Agriculture Western Australia 7. Canola establishment survey 2000, Rafiul Alam, Paul Carmody, Greg Hamilton and Adrian Cox, Agriculture Western Australia 8. Tramline farming for more canola, Paul Blackwell, Agriculture Western Australia NUTRITION 9. Comparing the phosphorus requirement of canola and wheat in WA, M.D.A. Bolland and M.J. Baker, Agriculture Western Australia 10. Will a rainy summer affect nitrogen requirement: Tailoring your fertiliser decisions using the new nitrogen calculator, A.J. Diggle, Agriculture Western Australia 11. Canola – More response to lime, Chris Gazeyand Paul Carmody, Centre for Cropping Systems, Agriculture Western Australia AGRONOMY 12. Hormone manipulation of canola development, Paul Carmody and Graham Walton, Agriculture Western Australia 13. Yield penalties with delayed sewing of canola, Imma Farre, CSIRO Plant Industry, Michael J. Robertson, CSIRO Sustainable Ecosystems, Graham H. Walton, Agriculture Western Australia, Senthold Asseng, CSIRO Plant Industry 14. Dry matter and oil accumulation in developing seeds of canola varieties at different sowing dates, Ping Si1, David Turner1 and David Harris2 , 1Plant Sciences, Faculty of Agriculture, The University of Western Australia, 2Chemistry Centre of Western Australia 13. Simulating oil concentrations in canola – virtually just the beginning, David Turner1 and Imma Farré2, 1Plant Sciences, Faculty of Agriculture, The University of Western Australia, 2CSIRO Plant Industry, Centre for Mediterranean Agricultural Research PESTS AND DISEASES 14. Further evidence that canola crops are resilient to damage by aphids, Françoise Berlandier and Christiaan Valentine, Entomology, Agriculture Western Australia 15. Management of Diamondback moth (DBM) in canola, David Cook, Peter Mangano, David Cousins, Françoise Berlandier, and Darryl Hardie, Crop Improvement Institute,Agriculture Western Australia 16. Effect of time of sowing in conjunction with fungicides on blackleg and yield of canola, Ravjit Khangura and Martin Barbetti, Agriculture Western Australia 17. Further developments in forecasting aphid and virus risk in canola, Debbie Thackray, Jenny Hawkes and Roger Jones, Agriculture Western Australia and Centre for Legumes in Mediterranean Agriculture 18. Efficiency of selected insecticides for the use on Diamondback Moth in canola, Kevin Walden, Agriculture Western Australia 19. Impact® applied ‘in furrow’ controls blackleg in canola, Cameron Weeks and Erin Hasson, Mingenew-Irwin Group Inc. 20. Effect of time of sowing and Impact® on canola yield, Esperance, Dave Eksteen, Agriculture Western Australia 21. Australian Plague Locust Campaign 2000, Kevin Walden, Agriculture Western Australia WEED CONTROL 22. New herbicide options for canola, John Moore and Paul Matson, Agriculture Western Australia HARVESTING 23. Effects of time of swathing and desiccant application on the seed yield and oil content of canola, Carla Thomas and Lionel Martin, Muresk Institute of Agriculture, Curtin University of Technology DECISION SUPPORT AND ADOPTION 24. Using canola monitoring groups to understand factors affecting canola production in Esperance, Dave Eksteen, Agriculture Western Australia 25. Nitrogen and canola, Dave Eksteen, Agriculture Western Australi
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