1
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Unexpected structures formed by the kinase RET C634R mutant extracellular domain suggest potential oncogenic mechanisms in MEN2A. J Biol Chem 2022; 298:102380. [PMID: 35985422 PMCID: PMC9490035 DOI: 10.1016/j.jbc.2022.102380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 07/31/2022] [Accepted: 08/03/2022] [Indexed: 11/25/2022] Open
Abstract
The RET receptor tyrosine kinase plays a pivotal role in cell survival, proliferation, and differentiation, and its abnormal activation leads to cancers through receptor fusions or point mutations. Mutations that disrupt the disulfide network in the extracellular domain (ECD) of RET drive multiple endocrine neoplasia type 2A (MEN2A), a hereditary syndrome associated with the development of thyroid cancers. However, structural details of how specific mutations affect RET are unclear. Here, we present the first structural insights into the ECD of the RET(C634R) mutant, the most common mutation in MEN2A. Using electron microscopy, we demonstrate that the C634R mutation causes ligand-independent dimerization of the RET ECD, revealing an unusual tail-to-tail conformation that is distinct from the ligand-induced signaling dimer of WT RET. Additionally, we show that the RETC634R ECD dimer can form complexes with at least two of the canonical RET ligands and that these complexes form very different structures than WT RET ECD upon ligand binding. In conclusion, this structural analysis of cysteine-mutant RET ECD suggests a potential key mechanism of cancer induction in MEN2A, both in the absence and presence of its native ligands, and may offer new targets for therapeutic intervention.
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2
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Conway JA, Kramer ER. Is activation of GDNF/RET signaling the answer for successful treatment of Parkinson's disease? A discussion of data from the culture dish to the clinic. Neural Regen Res 2021; 17:1462-1467. [PMID: 34916419 PMCID: PMC8771118 DOI: 10.4103/1673-5374.327330] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The neurotrophic signaling of glial cell line-derived neurotrophic factor (GDNF) with its canonical receptor, the receptor tyrosine kinase RET, coupled together with the GDNF family receptor alpha 1 is important for dopaminergic neuron survival and physiology in cell culture experiments and animal models. This prompted the idea to try GDNF/RET signaling as a therapeutic approach to treat Parkinson's disease with the hallmark of dopaminergic cell death in the substantia nigra of the midbrain. Despite several clinical trials with GDNF in Parkinson's disease patients, which mainly focused on optimizing the GDNF delivery technique, benefits were only seen in a few patients. In general, the endpoints did not show significant improvements. This suggests that it will be helpful to learn more about the basic biology of this fascinating but complicated GDNF/RET signaling system in the dopaminergic midbrain and about recent developments in the field to facilitate its use in the clinic. Here we will refer to the latest publications and point out important open questions in the field.
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Affiliation(s)
- James A Conway
- Institute of Translational and Stratified Medicine, Peninsula Medical School, Faculty of Health, University of Plymouth, Devon, UK
| | - Edgar R Kramer
- Institute of Translational and Stratified Medicine, Peninsula Medical School, Faculty of Health, University of Plymouth, Devon, UK
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3
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Cate RL, di Clemente N, Racine C, Groome NP, Pepinsky RB, Whitty A. The anti-Müllerian hormone prodomain is displaced from the hormone/prodomain complex upon bivalent binding to the hormone receptor. J Biol Chem 2021; 298:101429. [PMID: 34801555 PMCID: PMC8801479 DOI: 10.1016/j.jbc.2021.101429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 11/03/2021] [Accepted: 11/16/2021] [Indexed: 11/28/2022] Open
Abstract
Noncovalent complexes of transforming growth factor-β family growth/differentiation factors with their prodomains are classified as latent or active, depending on whether the complexes can bind their respective receptors. For the anti-Müllerian hormone (AMH), the hormone-prodomain complex is active, and the prodomain is displaced upon binding to its type II receptor, AMH receptor type-2 (AMHR2), on the cell surface. However, the mechanism by which this displacement occurs is unclear. Here, we used ELISA assays to measure the dependence of prodomain displacement on AMH concentration and analyzed results with respect to the behavior expected for reversible binding in combination with ligand-induced receptor dimerization. We found that, in solution, the prodomain has a high affinity for the growth factor (GF) (Kd = 0.4 pM). Binding of the AMH complex to a single AMHR2 molecule does not affect this Kd and does not induce prodomain displacement, indicating that the receptor binding site in the AMH complex is fully accessible to AMHR2. However, recruitment of a second AMHR2 molecule to bind the ligand bivalently leads to a 1000-fold increase in the Kd for the AMH complex, resulting in rapid release of the prodomain. Displacement occurs only if the AMHR2 is presented on a surface, indicating that prodomain displacement is caused by a conformational change in the GF induced by bivalent binding to AMHR2. In addition, we demonstrate that the bone morphogenetic protein 7 prodomain is displaced from the complex with its GF by a similar process, suggesting that this may represent a general mechanism for receptor-mediated prodomain displacement in this ligand family.
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Affiliation(s)
- Richard L Cate
- Department of Chemistry, Boston University, Boston, Massachusetts, USA.
| | - Nathalie di Clemente
- INSERM, Centre de Recherche Saint Antoine (CRSA), IHU ICAN, Sorbonne Université, Paris, France
| | - Chrystèle Racine
- INSERM, Centre de Recherche Saint Antoine (CRSA), IHU ICAN, Sorbonne Université, Paris, France
| | - Nigel P Groome
- School of Biological and Molecular Sciences, Oxford Brookes University, Headington, Oxford, UK
| | - R Blake Pepinsky
- Department of Biotherapeutic and Medicinal Sciences, Biogen, Cambridge, Massachusetts, USA
| | - Adrian Whitty
- Department of Chemistry, Boston University, Boston, Massachusetts, USA
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4
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Viisanen H, Nuotio U, Kambur O, Mahato AK, Jokinen V, Lilius T, Li W, Santos HA, Karelson M, Rauhala P, Kalso E, Sidorova YA. Novel RET agonist for the treatment of experimental neuropathies. Mol Pain 2021; 16:1744806920950866. [PMID: 32811276 PMCID: PMC7440726 DOI: 10.1177/1744806920950866] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The glial cell line-derived neurotrophic factor (GDNF) family ligands (GFLs) alleviate symptoms of experimental neuropathy, protect and stimulate regeneration of sensory neurons in animal models of neuropathic pain, and restore their functional activity. However, clinical development of GFL proteins is complicated by their poor pharmacokinetic properties and multiple effects mediated by several receptors. Previously, we have identified a small molecule that selectively activates the major signal transduction unit of the GFL receptor complex, receptor tyrosine kinase RET, as an alternative to GFLs, for the treatment of neuropathic pain. We then introduced a series of chemical changes to improve the biological activity of these compounds and tested an optimized compound named BT44 in a panel of biological assays. BT44 efficiently and selectively stimulated the GFL receptor RET and activated the intracellular mitogene-activated protein kinase/extracellular signal-regulated kinase pathway in immortalized cells. In cultured sensory neurons, BT44 stimulated neurite outgrowth with an efficacy comparable to that of GFLs. BT44 alleviated mechanical hypersensitivity in surgery- and diabetes-induced rat models of neuropathic pain. In addition, BT44 normalized, to a certain degree, the expression of nociception-related neuronal markers which were altered by spinal nerve ligation, the neuropathy model used in this study. Our results suggest that the GFL mimetic BT44 is a promising new lead for the development of novel disease-modifying agents for the treatment of neuropathy and neuropathic pain.
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Affiliation(s)
- Hanna Viisanen
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Ulpukka Nuotio
- Laboratory of Molecular Neuroscience, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Oleg Kambur
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Arun Kumar Mahato
- Laboratory of Molecular Neuroscience, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Viljami Jokinen
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Tuomas Lilius
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Wei Li
- Laboratory of Molecular Neuroscience, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.,Drug Research Program, Division of Pharmaceutical Chemistry and Technology, University of Helsinki, Helsinki, Finland
| | - Hélder A Santos
- Drug Research Program, Division of Pharmaceutical Chemistry and Technology, University of Helsinki, Helsinki, Finland.,Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Mati Karelson
- Institute of Chemistry, Tartu University, Tartu, Estonia
| | - Pekka Rauhala
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Eija Kalso
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Yulia A Sidorova
- Laboratory of Molecular Neuroscience, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.,Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
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5
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Ingles-Prieto A, Furthmann N, Crossman SH, Tichy AM, Hoyer N, Petersen M, Zheden V, Biebl J, Reichhart E, Gyoergy A, Siekhaus DE, Soba P, Winklhofer KF, Janovjak H. Optogenetic delivery of trophic signals in a genetic model of Parkinson's disease. PLoS Genet 2021; 17:e1009479. [PMID: 33857132 PMCID: PMC8049241 DOI: 10.1371/journal.pgen.1009479] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/10/2021] [Indexed: 12/19/2022] Open
Abstract
Optogenetics has been harnessed to shed new mechanistic light on current and future therapeutic strategies. This has been to date achieved by the regulation of ion flow and electrical signals in neuronal cells and neural circuits that are known to be affected by disease. In contrast, the optogenetic delivery of trophic biochemical signals, which support cell survival and are implicated in degenerative disorders, has never been demonstrated in an animal model of disease. Here, we reengineered the human and Drosophila melanogaster REarranged during Transfection (hRET and dRET) receptors to be activated by light, creating one-component optogenetic tools termed Opto-hRET and Opto-dRET. Upon blue light stimulation, these receptors robustly induced the MAPK/ERK proliferative signaling pathway in cultured cells. In PINK1B9 flies that exhibit loss of PTEN-induced putative kinase 1 (PINK1), a kinase associated with familial Parkinson's disease (PD), light activation of Opto-dRET suppressed mitochondrial defects, tissue degeneration and behavioral deficits. In human cells with PINK1 loss-of-function, mitochondrial fragmentation was rescued using Opto-dRET via the PI3K/NF-кB pathway. Our results demonstrate that a light-activated receptor can ameliorate disease hallmarks in a genetic model of PD. The optogenetic delivery of trophic signals is cell type-specific and reversible and thus has the potential to inspire novel strategies towards a spatio-temporal regulation of tissue repair.
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Affiliation(s)
- Alvaro Ingles-Prieto
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Nikolas Furthmann
- Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Samuel H. Crossman
- Australian Regenerative Medicine Institute (ARMI), Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton/Melbourne, Australia
- European Molecular Biology Laboratory Australia (EMBL Australia), Monash University, Clayton/Melbourne, Australia
| | - Alexandra-Madelaine Tichy
- Australian Regenerative Medicine Institute (ARMI), Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton/Melbourne, Australia
- European Molecular Biology Laboratory Australia (EMBL Australia), Monash University, Clayton/Melbourne, Australia
| | - Nina Hoyer
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Meike Petersen
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Vanessa Zheden
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Julia Biebl
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Eva Reichhart
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
- Australian Regenerative Medicine Institute (ARMI), Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton/Melbourne, Australia
- European Molecular Biology Laboratory Australia (EMBL Australia), Monash University, Clayton/Melbourne, Australia
| | - Attila Gyoergy
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Daria E. Siekhaus
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Peter Soba
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Konstanze F. Winklhofer
- Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Harald Janovjak
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
- Australian Regenerative Medicine Institute (ARMI), Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton/Melbourne, Australia
- European Molecular Biology Laboratory Australia (EMBL Australia), Monash University, Clayton/Melbourne, Australia
- * E-mail:
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6
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Bargagna‐Mohan P, Schultz G, Rheaume B, Trakhtenberg EF, Robson P, Pal‐Ghosh S, Stepp MA, Given KS, Macklin WB, Mohan R. Corneal nonmyelinating Schwann cells illuminated by single-cell transcriptomics and visualized by protein biomarkers. J Neurosci Res 2021; 99:731-749. [PMID: 33197966 PMCID: PMC7894186 DOI: 10.1002/jnr.24757] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 10/05/2020] [Accepted: 10/25/2020] [Indexed: 12/23/2022]
Abstract
The cornea is the most innervated tissue in the human body. Myelinated axons upon inserting into the peripheral corneal stroma lose their myelin sheaths and continue into the central cornea wrapped by only nonmyelinating corneal Schwann cells (nm-cSCs). This anatomical organization is believed to be important for central vision. Here we employed single-cell RNA sequencing (scRNA-seq), microscopy, and transgenics to characterize these nm-cSCs of the central cornea. Using principal component analysis, uniform manifold approximation and projection, and unsupervised hierarchal cell clustering of scRNA-seq data derived from central corneal cells of male rabbits, we successfully identified several clusters representing different corneal cell types, including a unique cell cluster representing nm-cSCs. To confirm protein expression of cSC genes, we performed cross-species validation, employing corneal whole-mount immunostaining with confocal microscopy in mouse corneas. The expression of several representative proteins of nm-cSCs were validated. As the proteolipid protein 1 (PLP1) gene was also expressed in nm-cSCs, we explored the Plp1-eGFP transgenic reporter mouse line to visualize cSCs. Specific and efficient eGFP expression was observed in cSCs in adult mice of different ages. Of several putative cornea-specific SC genes identified, Dickkopf-related protein 1 was shown to be present in nm-cSCs. Taken together, our findings, for the first time, identify important insights and tools toward the study nm-cSCs in isolated tissue and adult animals. We expect that our results will advance the future study of nm-cSCs in applications of nerve repair, and provide a resource for the study of corneal sensory function.
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Affiliation(s)
- Paola Bargagna‐Mohan
- Department of NeuroscienceUniversity of Connecticut Health CenterFarmingtonCTUSA
| | - Gwendolyn Schultz
- Department of NeuroscienceUniversity of Connecticut Health CenterFarmingtonCTUSA
| | - Bruce Rheaume
- Department of NeuroscienceUniversity of Connecticut Health CenterFarmingtonCTUSA
| | | | - Paul Robson
- Department of Genetics & Genome SciencesUniversity of Connecticut Health CenterFarmingtonCTUSA
- The Jackson Laboratory for Genomic MedicineFarmingtonCTUSA
| | - Sonali Pal‐Ghosh
- Department of Anatomy and Regenerative BiologyGeorge Washington University Medical SchoolWashingtonDCUSA
| | - Mary Ann Stepp
- Department of Anatomy and Regenerative BiologyGeorge Washington University Medical SchoolWashingtonDCUSA
| | - Katherine S. Given
- Department of Cell and Developmental BiologyUniversity of Colorado School of MedicineAuroraCOUSA
| | - Wendy B. Macklin
- Department of Cell and Developmental BiologyUniversity of Colorado School of MedicineAuroraCOUSA
| | - Royce Mohan
- Department of NeuroscienceUniversity of Connecticut Health CenterFarmingtonCTUSA
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7
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Ferrini F, Salio C, Boggio EM, Merighi A. Interplay of BDNF and GDNF in the Mature Spinal Somatosensory System and Its Potential Therapeutic Relevance. Curr Neuropharmacol 2021; 19:1225-1245. [PMID: 33200712 PMCID: PMC8719296 DOI: 10.2174/1570159x18666201116143422] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/17/2020] [Accepted: 10/05/2020] [Indexed: 11/22/2022] Open
Abstract
The growth factors BDNF and GDNF are gaining more and more attention as modulators of synaptic transmission in the mature central nervous system (CNS). The two molecules undergo a regulated secretion in neurons and may be anterogradely transported to terminals where they can positively or negatively modulate fast synaptic transmission. There is today a wide consensus on the role of BDNF as a pro-nociceptive modulator, as the neurotrophin has an important part in the initiation and maintenance of inflammatory, chronic, and/or neuropathic pain at the peripheral and central level. At the spinal level, BDNF intervenes in the regulation of chloride equilibrium potential, decreases the excitatory synaptic drive to inhibitory neurons, with complex changes in GABAergic/glycinergic synaptic transmission, and increases excitatory transmission in the superficial dorsal horn. Differently from BDNF, the role of GDNF still remains to be unraveled in full. This review resumes the current literature on the interplay between BDNF and GDNF in the regulation of nociceptive neurotransmission in the superficial dorsal horn of the spinal cord. We will first discuss the circuitries involved in such a regulation, as well as the reciprocal interactions between the two factors in nociceptive pathways. The development of small molecules specifically targeting BDNF, GDNF and/or downstream effectors is opening new perspectives for investigating these neurotrophic factors as modulators of nociceptive transmission and chronic pain. Therefore, we will finally consider the molecules of (potential) pharmacological relevance for tackling normal and pathological pain.
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Affiliation(s)
- Francesco Ferrini
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
- Department of Psychiatry & Neuroscience, Université Laval, Québec, Canada
| | - Chiara Salio
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Elena M. Boggio
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Adalberto Merighi
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
- National Institute of Neuroscience, Grugliasco, Italy
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8
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Sidorova YA, Saarma M. Can Growth Factors Cure Parkinson's Disease? Trends Pharmacol Sci 2020; 41:909-922. [PMID: 33198924 DOI: 10.1016/j.tips.2020.09.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 09/25/2020] [Accepted: 09/30/2020] [Indexed: 01/03/2023]
Abstract
Growth factors (GFs) hold considerable promise for disease modification in neurodegenerative disorders because they can protect and restore degenerating neurons and also enhance their functional activity. However, extensive efforts applied to utilize their therapeutic potential in humans have achieved limited success so far. Multiple clinical trials with GFs were performed in Parkinson's disease (PD) patients, in whom diagnostic symptoms of the disease are caused by advanced degeneration of nigrostriatal dopamine neurons (DNs), but the results of these trials are controversial. This review discusses recent developments in the field of therapeutic use of GFs, problems and obstacles related to this use, suggests the ways to overcome these issues, and alternative approaches that can be used to utilize the potential ofGFsin PD management.
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Affiliation(s)
- Yulia A Sidorova
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Mart Saarma
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.
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9
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Mahato AK, Sidorova YA. Glial cell line-derived neurotrophic factors (GFLs) and small molecules targeting RET receptor for the treatment of pain and Parkinson's disease. Cell Tissue Res 2020; 382:147-160. [PMID: 32556722 PMCID: PMC7529621 DOI: 10.1007/s00441-020-03227-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/27/2020] [Indexed: 02/07/2023]
Abstract
Rearranged during transfection (RET), in complex with glial cell line-derived (GDNF) family receptor alpha (GFRα), is the canonical signaling receptor for GDNF family ligands (GFLs) expressed in both central and peripheral parts of the nervous system and also in non-neuronal tissues. RET-dependent signaling elicited by GFLs has an important role in the development, maintenance and survival of dopamine and sensory neurons. Both Parkinson's disease and neuropathic pain are devastating disorders without an available cure, and at the moment are only treated symptomatically. GFLs have been studied extensively in animal models of Parkinson's disease and neuropathic pain with remarkable outcomes. However, clinical trials with recombinant or viral vector-encoded GFL proteins have produced inconclusive results. GFL proteins are not drug-like; they have poor pharmacokinetic properties and activate multiple receptors. Targeting RET and/or GFRα with small molecules may resolve the problems associated with using GFLs as drugs and can result in the development of therapeutics for disease-modifying treatments against Parkinson's disease and neuropathic pain.
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Affiliation(s)
- Arun Kumar Mahato
- Institute of Biotechnology, HiLIFE, University of Helsinki, Viikinkaari 5D, 00014, Helsinki, Finland
| | - Yulia A Sidorova
- Institute of Biotechnology, HiLIFE, University of Helsinki, Viikinkaari 5D, 00014, Helsinki, Finland.
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10
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Li J, Shang G, Chen YJ, Brautigam CA, Liou J, Zhang X, Bai XC. Cryo-EM analyses reveal the common mechanism and diversification in the activation of RET by different ligands. eLife 2019; 8:e47650. [PMID: 31535977 PMCID: PMC6760901 DOI: 10.7554/elife.47650] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 09/18/2019] [Indexed: 01/29/2023] Open
Abstract
RET is a receptor tyrosine kinase (RTK) that plays essential roles in development and has been implicated in several human diseases. Different from most of RTKs, RET requires not only its cognate ligands but also co-receptors for activation, the mechanisms of which remain unclear due to lack of high-resolution structures of the ligand/co-receptor/receptor complexes. Here, we report cryo-EM structures of the extracellular region ternary complexes of GDF15/GFRAL/RET, GDNF/GFRα1/RET, NRTN/GFRα2/RET and ARTN/GFRα3/RET. These structures reveal that all the four ligand/co-receptor pairs, while using different atomic interactions, induce a specific dimerization mode of RET that is poised to bring the two kinase domains into close proximity for cross-phosphorylation. The NRTN/GFRα2/RET dimeric complex further pack into a tetrameric assembly, which is shown by our cell-based assays to regulate the endocytosis of RET. Our analyses therefore reveal both the common mechanism and diversification in the activation of RET by different ligands.
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Affiliation(s)
- Jie Li
- Department of BiophysicsUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Guijun Shang
- Department of PharmacologyUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Yu-Ju Chen
- Department of PhysiologyUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Chad A Brautigam
- Department of BiophysicsUniversity of Texas Southwestern Medical CenterDallasUnited States
- Department of MicrobiologyUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Jen Liou
- Department of PhysiologyUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Xuewu Zhang
- Department of BiophysicsUniversity of Texas Southwestern Medical CenterDallasUnited States
- Department of PharmacologyUniversity of Texas Southwestern Medical CenterDallasUnited States
| | - Xiao-chen Bai
- Department of BiophysicsUniversity of Texas Southwestern Medical CenterDallasUnited States
- Department of Cell BiologyUniversity of Texas Southwestern Medical CenterDallasUnited States
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11
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Bigalke JM, Aibara S, Roth R, Dahl G, Gordon E, Dorbéus S, Amunts A, Sandmark J. Cryo-EM structure of the activated RET signaling complex reveals the importance of its cysteine-rich domain. SCIENCE ADVANCES 2019; 5:eaau4202. [PMID: 31392261 PMCID: PMC6669014 DOI: 10.1126/sciadv.aau4202] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
Signaling through the receptor tyrosine kinase RET is essential during normal development. Both gain- and loss-of-function mutations are involved in a variety of diseases, yet the molecular details of receptor activation have remained elusive. We have reconstituted the complete extracellular region of the RET signaling complex together with Neurturin (NRTN) and GFRα2 and determined its structure at 5.7-Å resolution by cryo-EM. The proteins form an assembly through RET-GFRα2 and RET-NRTN interfaces. Two key interaction points required for RET extracellular domain binding were observed: (i) the calcium-binding site in RET that contacts GFRα2 domain 3 and (ii) the RET cysteine-rich domain interaction with NRTN. The structure highlights the importance of the RET cysteine-rich domain and allows proposition of a model to explain how complex formation leads to RET receptor dimerization and its activation. This provides a framework for targeting RET activity and for further exploration of mechanisms underlying neurological diseases.
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Affiliation(s)
- Janna M. Bigalke
- Structure, Biophysics and Fragment-Based Lead Generation, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Shintaro Aibara
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165 Solna, Sweden
| | - Robert Roth
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Göran Dahl
- Structure, Biophysics and Fragment-Based Lead Generation, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Euan Gordon
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Sarah Dorbéus
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - A. Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165 Solna, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Jenny Sandmark
- Structure, Biophysics and Fragment-Based Lead Generation, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
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12
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Sandmark J, Dahl G, Öster L, Xu B, Johansson P, Akerud T, Aagaard A, Davidsson P, Bigalke JM, Winzell MS, Rainey GJ, Roth RG. Structure and biophysical characterization of the human full-length neurturin-GFRa2 complex: A role for heparan sulfate in signaling. J Biol Chem 2018; 293:5492-5508. [PMID: 29414779 DOI: 10.1074/jbc.ra117.000820] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 01/15/2018] [Indexed: 12/13/2022] Open
Abstract
Neurturin (NRTN) provides trophic support to neurons and is considered a therapeutic agent for neurodegenerative diseases, such as Parkinson's disease. It binds to its co-receptor GFRa2, and the resulting NRTN-GFRa2 complex activates the transmembrane receptors rearranged during transfection (RET) or the neural cell adhesion molecule (NCAM). We report the crystal structure of NRTN, alone and in complex with GFRa2. This is the first crystal structure of a GFRa with all three domains and shows that domain 1 does not interact directly with NRTN, but it may support an interaction with RET and/or NCAM, via a highly conserved surface. In addition, biophysical results show that the relative concentration of GFRa2 on cell surfaces can affect the functional affinity of NRTN through avidity effects. We have identified a heparan sulfate-binding site on NRTN and a putative binding site in GFRa2, suggesting that heparan sulfate has a role in the assembly of the signaling complex. We further show that mutant NRTN with reduced affinity for heparan sulfate may provide a route forward for delivery of NRTN with increased exposure in preclinical in vivo models and ultimately to Parkinson's patients.
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Affiliation(s)
- Jenny Sandmark
- From the Departments of Structure, Biophysics and Fragment-based Lead Generation, Discovery Sciences
| | - Göran Dahl
- From the Departments of Structure, Biophysics and Fragment-based Lead Generation, Discovery Sciences
| | - Linda Öster
- From the Departments of Structure, Biophysics and Fragment-based Lead Generation, Discovery Sciences
| | - Bingze Xu
- the Division of Medical Inflammation Research, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden.,Discovery Biology, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg 43183, Sweden
| | - Patrik Johansson
- From the Departments of Structure, Biophysics and Fragment-based Lead Generation, Discovery Sciences
| | - Tomas Akerud
- From the Departments of Structure, Biophysics and Fragment-based Lead Generation, Discovery Sciences
| | - Anna Aagaard
- From the Departments of Structure, Biophysics and Fragment-based Lead Generation, Discovery Sciences
| | - Pia Davidsson
- Bioscience, Cardiovascular and Metabolic Diseases, and
| | - Janna M Bigalke
- From the Departments of Structure, Biophysics and Fragment-based Lead Generation, Discovery Sciences
| | | | - G Jonah Rainey
- the Department of Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, Maryland 20878, and
| | - Robert G Roth
- Discovery Biology, Discovery Sciences, IMED Biotech Unit, AstraZeneca, Gothenburg 43183, Sweden,
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13
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Plaza-Menacho I. Structure and function of RET in multiple endocrine neoplasia type 2. Endocr Relat Cancer 2018; 25:T79-T90. [PMID: 29175871 DOI: 10.1530/erc-17-0354] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 12/31/2022]
Abstract
It has been twenty-five years since the discovery of oncogenic germline RET mutations as the cause of multiple endocrine neoplasia type 2 (MEN2). Intensive work over the last two and a half decades on RET genetics, signaling and cell biology has provided the current bases for the genotype-phenotype and functional correlations within this cancer syndrome. On the contrary, the structural and molecular basis for RET tyrosine kinase domain activation and oncogenic deregulation has remained largely elusive. Recent studies with a strong crystallographic and biochemical focus have started to elucidate key insights into such molecular and atomic details revealing unexpected and private mechanisms of actions and molecular determinants not previously envisioned. This review focuses on the structure and function of the RET receptor, and in particular, on what a more detailed view of the protein itself and what the current structural and molecular information tell us about the genotype and phenotype relationships in the cancer syndrome MEN2.
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Affiliation(s)
- Iván Plaza-Menacho
- KinasesProtein Phosphorylation and Cancer, Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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14
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Saarenpää T, Kogan K, Sidorova Y, Mahato AK, Tascón I, Kaljunen H, Yu L, Kallijärvi J, Jurvansuu J, Saarma M, Goldman A. Zebrafish GDNF and its co-receptor GFRα1 activate the human RET receptor and promote the survival of dopaminergic neurons in vitro. PLoS One 2017; 12:e0176166. [PMID: 28467503 PMCID: PMC5415192 DOI: 10.1371/journal.pone.0176166] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Accepted: 04/06/2017] [Indexed: 12/14/2022] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is a ligand that activates, through co-receptor GDNF family receptor alpha-1 (GFRα1) and receptor tyrosine kinase “RET”, several signaling pathways crucial in the development and sustainment of multiple neuronal populations. We decided to study whether non-mammalian orthologs of these three proteins have conserved their function: can they activate the human counterparts? Using the baculovirus expression system, we expressed and purified Danio rerio RET, and its binding partners GFRα1 and GDNF, and Drosophila melanogaster RET and two isoforms of co-receptor GDNF receptor-like. Our results report high-level insect cell expression of post-translationally modified and dimerized zebrafish RET and its binding partners. We also found that zebrafish GFRα1 and GDNF are comparably active as mammalian cell-produced ones. We also report the first measurements of the affinity of the complex to RET in solution: at least for zebrafish, the Kd for GFRα1-GDNF binding RET is 5.9 μM. Surprisingly, we also found that zebrafish GDNF as well as zebrafish GFRα1 robustly activated human RET signaling and promoted the survival of cultured mouse dopaminergic neurons with comparable efficiency to mammalian GDNF, unlike E. coli-produced human proteins. These results contradict previous studies suggesting that mammalian GFRα1 and GDNF cannot bind and activate non-mammalian RET and vice versa.
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Affiliation(s)
- Tuulia Saarenpää
- Department of Biochemistry, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Konstantin Kogan
- Department of Biochemistry, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Yulia Sidorova
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Arun Kumar Mahato
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Igor Tascón
- Department of Biochemistry, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Heidi Kaljunen
- Department of Biochemistry, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Liying Yu
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jukka Kallijärvi
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jaana Jurvansuu
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Mart Saarma
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Adrian Goldman
- Department of Biochemistry, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- * E-mail:
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15
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Gao C, Grøtli M, Eriksson LA. Defects in the calcium-binding region drastically affect the cadherin-like domains of RET tyrosine kinase. Phys Chem Chem Phys 2017; 18:8673-81. [PMID: 26950000 DOI: 10.1039/c6cp00042h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mutations in the rearranged during transfection (RET) tyrosine kinase gene leading to gain or loss of function have been associated with the development of several human cancers and Hirschsprung's disease (HSCR). However, to what extent these mutations affect individual bio-molecular functions remains unclear. In this article, the functionally significant mutations in the RET CLD1-4 calcium-binding site which lead to HSCR, and depletion of calcium ions in the RET CLD1-4 calcium binding site, were investigated by molecular dynamics simulations--to understand the mechanistic action of the mutations or loss of calcium ions in altering the protein kinase structure, dynamics, and stability. The mutations or loss of calcium ions change the local conformation and change the free energy landscape. Specifically, the mutations and loss of calcium ions decrease the radius of gyration of the whole structure, leading to improper protein folding and GFL-GFRα contact site reduction. Furthermore, based on the most populated conformation in the wildtype MD simulations, a pharmacophore was generated by fragment docking to identify key features of the possible inhibitors targeting the calcium binding site. Overall, the findings may provide useful structural insights into the molecular mechanism underlying RET calcium-binding site mutations and assist in development of novel drugs targeting the extracellular ligand contact site of wildtype RET.
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Affiliation(s)
- Chunxia Gao
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden.
| | - Morten Grøtli
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden.
| | - Leif A Eriksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden.
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16
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Sidorova YA, Saarma M. Glial cell line-derived neurotrophic factor family ligands and their therapeutic potential. Mol Biol 2016. [DOI: 10.1134/s0026893316040105] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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17
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Abstract
Communication between cells in a multicellular organism occurs by the production of ligands (proteins, peptides, fatty acids, steroids, gases, and other low-molecular-weight compounds) that are either secreted by cells or presented on their surface, and act on receptors on, or in, other target cells. Such signals control cell growth, migration, survival, and differentiation. Signaling receptors can be single-span plasma membrane receptors associated with tyrosine or serine/threonine kinase activities, proteins with seven transmembrane domains, or intracellular receptors. Ligand-activated receptors convey signals into the cell by activating signaling pathways that ultimately affect cytosolic machineries or nuclear transcriptional programs or by directly translocating to the nucleus to regulate transcription.
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Affiliation(s)
- Carl-Henrik Heldin
- Ludwig Institute for Cancer Research, Science for Life Laboratory, Uppsala University, SE-75124 Uppsala, Sweden
| | - Benson Lu
- The Salk Institute for Biological Studies, Gene Expression Laboratory, La Jolla, California 92037
| | - Ron Evans
- The Salk Institute for Biological Studies, Gene Expression Laboratory, La Jolla, California 92037
| | - J Silvio Gutkind
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland 20892-4340
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18
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Danwen Q, Code C, Quan C, Gong BJ, Arndt J, Pepinsky B, Rand KD, Houde D. Investigating the Role of Artemin Glycosylation. Pharm Res 2016; 33:1383-98. [DOI: 10.1007/s11095-016-1880-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/11/2016] [Indexed: 11/24/2022]
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19
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Cai J, Li L, Ye L, Jiang X, Shen L, Gao Z, Fang W, Huang F, Su T, Zhou Y, Wang W, Ning G. Exome sequencing reveals mutant genes with low penetrance involved in MEN2A-associated tumorigenesis. Endocr Relat Cancer 2015; 22:23-33. [PMID: 25404689 DOI: 10.1530/erc-14-0225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Activating rearranged during transfection (RET) mutations function as the initiating causative mutation for multiple endocrine neoplasia type 2A (MEN2A). However, no conclusive findings regarding the non-RET genetic events have been reported. This is the first study, to our knowledge, examining genomic alterations in matched MEN2A-associated tumors. We performed exome sequencing and SNP array analysis of matched MEN2A tumors and germline DNA. Somatic alterations were validated in an independent set of patients using Sanger sequencing. Genes of functional interest were further evaluated. The germline RET mutation was found in all MEN2A-component tumors. Thirty-two somatic mutations were identified in the nine MEN2A-associated tumors, of which 28 (87.5%) were point mutations and 4 (12.5%) were small insertions, duplications, or deletions. We sequenced all the mutations as well as coding sequence regions of the 12 genes in an independent sample set including 35 medullary thyroid cancers (20 MEN2A) and 34 PCCs (22 MEN2A), but found no recurrent mutations. Recurrent alterations were found in 13 genes with either mutations or alterations in copy number, including an EIF4G1 mutation (p. E1147V). Mutation of EIF4G1 led to increased cell proliferation and RET/MAPK phosphorylation, while knockdown of EIF4G1 led to reduced cell proliferation and RET/MAPK phosphorylation in TT, MZ-CRC1, and PC-12 cells. We found fewer somatic mutations in endocrine tumors compared with non-endocrine tumors. RET was the primary driver in MEN2A-associated tumors. However, low-frequency alterations such as EIF4G1 might participate in MEN2A-associated tumorigenesis, possibly by regulating the activity of the RET pathway.
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Affiliation(s)
- Jie Cai
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Lin Li
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Lei Ye
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Xiaohua Jiang
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Liyun Shen
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Zhibo Gao
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Weiyuan Fang
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Fengjiao Huang
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Tingwei Su
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Yulin Zhou
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Weiqing Wang
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
| | - Guang Ning
- School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China School of MedicineShanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University, #197 Ruijin 2nd Road, Shanghai 200025 People's Republic of ChinaBGI-ShenzhenShenzhen 518083, ChinaLaboratory for Endocrine and Metabolic Diseases of Institute of Health ScienceShanghai Jiao Tong University School of Medicine and Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, #227 South Chongqing Road, Shanghai 200025, People's Republic of China
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20
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Li S, Bhave D, Chow JM, Riera TV, Schlee S, Rauch S, Atanasova M, Cate RL, Whitty A. Quantitative analysis of receptor tyrosine kinase-effector coupling at functionally relevant stimulus levels. J Biol Chem 2015; 290:10018-36. [PMID: 25635057 DOI: 10.1074/jbc.m114.602268] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Indexed: 01/16/2023] Open
Abstract
A major goal of current signaling research is to develop a quantitative understanding of how receptor activation is coupled to downstream signaling events and to functional cellular responses. Here, we measure how activation of the RET receptor tyrosine kinase on mouse neuroblastoma cells by the neurotrophin artemin (ART) is quantitatively coupled to key downstream effectors. We show that the efficiency of RET coupling to ERK and Akt depends strongly on ART concentration, and it is highest at the low (∼100 pM) ART levels required for neurite outgrowth. Quantitative discrimination between ERK and Akt pathway signaling similarly is highest at this low ART concentration. Stimulation of the cells with 100 pM ART activated RET at the rate of ∼10 molecules/cell/min, leading at 5-10 min to a transient peak of ∼150 phospho-ERK (pERK) molecules and ∼50 pAkt molecules per pRET, after which time the levels of these two signaling effectors fell by 25-50% while the pRET levels continued to slowly rise. Kinetic experiments showed that signaling effectors in different pathways respond to RET activation with different lag times, such that the balance of signal flux among the different pathways evolves over time. Our results illustrate that measurements using high, super-physiological growth factor levels can be misleading about quantitative features of receptor signaling. We propose a quantitative model describing how receptor-effector coupling efficiency links signal amplification to signal sensitization between receptor and effector, thereby providing insight into design principles underlying how receptors and their associated signaling machinery decode an extracellular signal to trigger a functional cellular outcome.
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Affiliation(s)
- Simin Li
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Devayani Bhave
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Jennifer M Chow
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Thomas V Riera
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Sandra Schlee
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Simone Rauch
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Mariya Atanasova
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Richard L Cate
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
| | - Adrian Whitty
- From the Department of Chemistry, Boston University, Boston, Massachusetts 02215
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21
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Goodman KM, Kjær S, Beuron F, Knowles PP, Nawrotek A, Burns EM, Purkiss AG, George R, Santoro M, Morris EP, McDonald NQ. RET recognition of GDNF-GFRα1 ligand by a composite binding site promotes membrane-proximal self-association. Cell Rep 2014; 8:1894-1904. [PMID: 25242331 DOI: 10.1016/j.celrep.2014.08.040] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/04/2014] [Accepted: 08/17/2014] [Indexed: 11/20/2022] Open
Abstract
The RET receptor tyrosine kinase is essential to vertebrate development and implicated in multiple human diseases. RET binds a cell surface bipartite ligand comprising a GDNF family ligand and a GFRα coreceptor, resulting in RET transmembrane signaling. We present a hybrid structural model, derived from electron microscopy (EM) and low-angle X-ray scattering (SAXS) data, of the RET extracellular domain (RET(ECD)), GDNF, and GFRα1 ternary complex, defining the basis for ligand recognition. RET(ECD) envelopes the dimeric ligand complex through a composite binding site comprising four discrete contact sites. The GFRα1-mediated contacts are crucial, particularly close to the invariant RET calcium-binding site, whereas few direct contacts are made by GDNF, explaining how distinct ligand/coreceptor pairs are accommodated. The RET(ECD) cysteine-rich domain (CRD) contacts both ligand components and makes homotypic membrane-proximal interactions occluding three different antibody epitopes. Coupling of these CRD-mediated interactions suggests models for ligand-induced RET activation and ligand-independent oncogenic deregulation.
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Affiliation(s)
- Kerry M Goodman
- Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Svend Kjær
- Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK; Protein Purification Facility, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Fabienne Beuron
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Phillip P Knowles
- Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Agata Nawrotek
- Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Emily M Burns
- Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Andrew G Purkiss
- Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Roger George
- Protein Purification Facility, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Massimo Santoro
- Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università di Napoli Federico II, via S. Pansini 5, 80131 Naples, Italy
| | - Edward P Morris
- Division of Structural Biology, The Institute of Cancer Research, London SW7 3RP, UK
| | - Neil Q McDonald
- Structural Biology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK; Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck College, Malet Street, London WC1E 7HX, UK.
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22
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The proform of glia cell line-derived neurotrophic factor: a potentially biologically active protein. Mol Neurobiol 2013; 49:234-50. [PMID: 23934644 DOI: 10.1007/s12035-013-8515-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 07/10/2013] [Indexed: 12/24/2022]
Abstract
Growing evidences have revealed that the proforms of several neurotrophins including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT3), by binding to p75 neurotrophin receptor and sortilin, could induce neuronal apoptosis and are implicated in the pathogenesis of various neurodegenerative diseases. The glial cell line-derived neurotrophic factor (GDNF), one of the most potent useful neurotrophic factors for the treatment of Parkinson's disease (PD), is firstly synthesized as the proform (proGDNF) like other neurotrophin NGF, BDNF, and NT3. However, little is known about proGDNF expression and secretion under physiological as well as pathological states in vivo or in vitro. In this study, we investigated the expression profile and dynamic changes of proGDNF in brains of aging and PD animal models, with the interesting finding that proGDNF was a predominant form of GDNF with molecular weight of about 36 kDa by reducing and nonreducing immunoblots in adult brains and was unregulated in the aging, lipopolysaccharide (LPS), and 1-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine (MPTP) insult. We further provided direct evidence that accompanied activation of primary astrocytes as well as C6 cell line induced by LPS stimulation, proGDNF was increasingly synthesized and released as the uncleaved form in cell culture. Taken together, our results strongly suggest that proGDNF may be a biologically active protein and has specific effects on the cells close to its secreting site, and a potentially important role of proGDNF signaling in the brains, in the glia-neuronal interaction or in the pathogenesis of PD, should merit further investigation.
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23
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Zhao H, Schuck P. Global multi-method analysis of affinities and cooperativity in complex systems of macromolecular interactions. Anal Chem 2012; 84:9513-9. [PMID: 23020071 PMCID: PMC3491091 DOI: 10.1021/ac302357w] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cooperativity, multisite, and multicomponent interactions are hallmarks of biological systems of interacting macromolecules. Their thermodynamic characterization is often very challenging due to the notoriously low information content of binding isotherms. We introduce a strategy for the global multimethod analysis of data from multiple techniques (GMMA) that exploits enhanced information content emerging from the mutual constraints of the simultaneous modeling of orthogonal observables from calorimetric, spectroscopic, hydrodynamic, biosensing, or other thermodynamic binding experiments. We describe new approaches to address statistical problems that arise in the analysis of dissimilar data sets. The GMMA approach can significantly increase the complexity of interacting systems that can be accurately thermodynamically characterized.
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Affiliation(s)
- Huaying Zhao
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
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Wang X. Structural studies of GDNF family ligands with their receptors-Insights into ligand recognition and activation of receptor tyrosine kinase RET. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1834:2205-12. [PMID: 23085183 DOI: 10.1016/j.bbapap.2012.10.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Accepted: 10/05/2012] [Indexed: 12/21/2022]
Abstract
RET is the receptor for glial cell line-derived neurotrophic factor family of ligands (GFLs). It is different from most other members in the receptor tyrosine kinase (RTK) family with the requirement of a co-receptor, GFRα, for ligand recognition and activation. Through the common signal transducer RET, GFLs are crucial for the development and maintenance of distinct sets of central and peripheral neurons, which has led to a series of studies towards understanding the structure, function and signaling mechanisms of GFLs with GFRα and RET receptors. Here I summarize our current understanding of the molecular basis underlying ligand recognition and activation of RET, focusing on the interactions of GFLs with their respective GFRα receptors, the recently determined crystal structure of RET extracellular region and a proposed GFL-GFRα-RET ternary complex model based on extensive structural, biochemical and functional data. This article is part of a Special Issue entitled: Emerging recognition and activation mechanisms of receptor tyrosine kinases.
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Affiliation(s)
- Xinquan Wang
- Center for Structural Biology, School of Life Sciences, Ministry of Education Key Laboratory of Protein Science, Medical Science Building C226, Tsinghua University, Beijing 100084, PR China.
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25
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Atanasova M, Whitty A. Understanding cytokine and growth factor receptor activation mechanisms. Crit Rev Biochem Mol Biol 2012; 47:502-30. [PMID: 23046381 DOI: 10.3109/10409238.2012.729561] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Our understanding of the detailed mechanism of action of cytokine and growth factor receptors - and particularly our quantitative understanding of the link between structure, mechanism and function - lags significantly behind our knowledge of comparable functional protein classes such as enzymes, G protein-coupled receptors, and ion channels. In particular, it remains controversial whether such receptors are activated by a mechanism of ligand-induced oligomerization, versus a mechanism in which the ligand binds to a pre-associated receptor dimer or oligomer that becomes activated through subsequent conformational rearrangement. A major limitation to progress has been the relative paucity of methods for performing quantitative mechanistic experiments on unmodified receptors expressed at endogenous levels on live cells. In this article, we review the current state of knowledge on the activation mechanisms of cytokine and growth factor receptors, critically evaluate the evidence for and against the different proposed mechanisms, and highlight other key questions that remain unanswered. New approaches and techniques have led to rapid recent progress in this area, and the field is poised for major advances in the coming years which promise to revolutionize our understanding of this large and biologically and medically important class of receptors.
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Affiliation(s)
- Mariya Atanasova
- Department of Chemistry, Boston University, Boston, MA 02215, USA
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Abstract
Synapses are the fundamental units of neural circuits that enable complex behaviors. The neuromuscular junction (NMJ), a synapse formed between a motoneuron and a muscle fiber, has contributed greatly to understanding of the general principles of synaptogenesis as well as of neuromuscular disorders. NMJ formation requires neural agrin, a motoneuron-derived protein, which interacts with LRP4 (low-density lipoprotein receptor-related protein 4) to activate the receptor tyrosine kinase MuSK (muscle-specific kinase). However, little is known of how signals are transduced from agrin to MuSK. Here, we present the first crystal structure of an agrin-LRP4 complex, consisting of two agrin-LRP4 heterodimers. Formation of the initial binary complex requires the z8 loop that is specifically present in neuronal, but not muscle, agrin and that promotes the synergistic formation of the tetramer through two additional interfaces. We show that the tetrameric complex is essential for neuronal agrin-induced acetylcholine receptor (AChR) clustering. Collectively, these results provide new insight into the agrin-LRP4-MuSK signaling cascade and NMJ formation and represent a novel mechanism for activation of receptor tyrosine kinases.
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Wagner SM, Zhu S, Nicolescu AC, Mulligan LM. Molecular mechanisms of RET receptor-mediated oncogenesis in multiple endocrine neoplasia 2. Clinics (Sao Paulo) 2012; 67 Suppl 1:77-84. [PMID: 22584710 PMCID: PMC3328826 DOI: 10.6061/clinics/2012(sup01)14] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multiple endocrine neoplasia type 2 is an inherited cancer syndrome characterized by tumors of thyroid and adrenal tissues. Germline mutations of the REarranged during Transfection (RET) proto-oncogene, leading to its unregulated activation, are the underlying cause of this disease. Multiple endocrine neoplasia type 2 has been a model in clinical cancer genetics, demonstrating how knowledge of the genetic basis can shape the diagnosis and treatment of the disease. Here, we discuss the nature and effects of the most common recurrent mutations of RET found in multiple endocrine neoplasia type 2. Current understanding of the molecular mechanisms of RET mutations and how they alter the structure and function of the RET protein leading to its aberrant activation, and the effects on RET localization and signaling are described.
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Affiliation(s)
- Simona M Wagner
- Division of Cancer Biology and Genetics, Cancer Research Institute, Department of Pathology & Molecular Medicine, Queen's University, Kingston, ON, Canada
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28
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Zhang W, Coldefy AS, Hubbard SR, Burden SJ. Agrin binds to the N-terminal region of Lrp4 protein and stimulates association between Lrp4 and the first immunoglobulin-like domain in muscle-specific kinase (MuSK). J Biol Chem 2011; 286:40624-30. [PMID: 21969364 DOI: 10.1074/jbc.m111.279307] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Neuromuscular synapse formation depends upon coordinated interactions between motor neurons and muscle fibers, leading to the formation of a highly specialized postsynaptic membrane and a highly differentiated nerve terminal. Synapse formation begins as motor axons approach muscles that are prepatterned in the prospective synaptic region in a manner that depends upon Lrp4, a member of the LDL receptor family, and muscle-specific kinase (MuSK), a receptor tyrosine kinase. Motor axons supply Agrin, which binds Lrp4 and stimulates further MuSK phosphorylation, stabilizing nascent synapses. How Agrin binds Lrp4 and stimulates MuSK kinase activity is poorly understood. Here, we demonstrate that Agrin binds to the N-terminal region of Lrp4, including a subset of the LDLa repeats and the first of four β-propeller domains, which promotes association between Lrp4 and MuSK and stimulates MuSK kinase activity. In addition, we show that Agrin stimulates the formation of a functional complex between Lrp4 and MuSK on the surface of myotubes in the absence of the transmembrane and intracellular domains of Lrp4. Further, we demonstrate that the first Ig-like domain in MuSK, which shares homology with the NGF-binding region in Tropomyosin Receptor Kinase (TrKA), is required for MuSK to bind Lrp4. These findings suggest that Lrp4 is a cis-acting ligand for MuSK, whereas Agrin functions as an allosteric and paracrine regulator to promote association between Lrp4 and MuSK.
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Affiliation(s)
- Wei Zhang
- Molecular Neurobiology Program, Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University Medical School, New York, New York 10016, USA
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Bruinzeel W, Masure S. Recombinant expression, purification and dimerization of the neurotrophic growth factor Artemin for in vitro and in vivo use. Protein Expr Purif 2011; 81:25-32. [PMID: 21907286 DOI: 10.1016/j.pep.2011.08.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 08/18/2011] [Accepted: 08/24/2011] [Indexed: 11/17/2022]
Abstract
Artemin (ARTN) is a neurotrophic growth factor of the GDNF ligand family that signals through the specific GFRα-3 coreceptor/cRet tyrosine kinase-mediated signaling cascade. Its expression and signaling action in adults are restricted to nociceptive sensory neurons in the dorsal root ganglia. Consequently, Artemin supports survival and growth of sensory neurons and has been studied as a possible treatment for neuropathic pain paradigms. In this paper, we describe the development of an efficient method for the recombinant bacterial production of large quantities of highly pure, biologically active ARTN for in vitro and in vivo studies. Using Escherichia coli expression of an NH(2)-terminal SUMO-Artemin fusion protein and subsequent refolding from inclusion bodies followed by cleavage of the SUMO fusion part, mature Artemin with a native NH(2)-terminal amino acid sequence was obtained at high purity (>99%). Experiments using the reducing agent dithiothreitol (DTT) demonstrated that the intermolecular disulphide bridge in the cysteine knot is dispensable for dimerization of stable ARTN monomers. Our production method could facilitate in vitro and in vivo experimentation for the possible development of Artemin as a therapeutic agent for neuropathic pain.
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Affiliation(s)
- Wouter Bruinzeel
- Department of Assay Development & Target Validation, C.R.E.A. Te, Janssen Research & Development, B-2340 Beerse, Belgium
| | - Stefan Masure
- Department of Assay Development & Target Validation, C.R.E.A. Te, Janssen Research & Development, B-2340 Beerse, Belgium.
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Exceptional Stability of Artemin Neurotrophic Factor Dimers: Effects of Temperature, pH, Buffer and Storage Conditions on Protein Integrity and Activity. Appl Biochem Biotechnol 2011; 165:1379-90. [DOI: 10.1007/s12010-011-9354-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 08/22/2011] [Indexed: 01/17/2023]
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Lamoureaux TL, Lee DH. Chemical activation of MEK1--a redox trigger for evaluating the effects of phosphorylation. Chem Commun (Camb) 2011; 47:8623-5. [PMID: 21717004 DOI: 10.1039/c1cc11745a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An approach to generate mimics of phosphorylated serine proteins chemically through site-specific sulfonation of cysteine is presented. This chemical modification is reversible in the presence of reducing agent and therefore is analogous to the kinase/phosphatase system used in nature.
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Affiliation(s)
- Toni L Lamoureaux
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
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Abstract
Recent structural studies of receptor tyrosine kinases (RTKs) have revealed unexpected diversity in the mechanisms of their activation by growth factor ligands. Strategies for inducing dimerization by ligand binding are surprisingly diverse, as are mechanisms that couple this event to activation of the intracellular tyrosine kinase domains. As our understanding of these details becomes increasingly sophisticated, it provides an important context for therapeutically countering the effects of pathogenic RTK mutations in cancer and other diseases. Much remains to be learned, however, about the complex signaling networks downstream from RTKs and how alterations in these networks are translated into cellular responses.
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Radivoyevitch T. Equilibrium model selection: dTTP induced R1 dimerization. BMC SYSTEMS BIOLOGY 2008; 2:15. [PMID: 18248678 PMCID: PMC2268910 DOI: 10.1186/1752-0509-2-15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 02/04/2008] [Indexed: 11/24/2022]
Abstract
Background Biochemical equilibria are usually modeled iteratively: given one or a few fitted models, if there is a lack of fit or over fitting, a new model with additional or fewer parameters is then fitted, and the process is repeated. The problem with this approach is that different analysts can propose and select different models and thus extract different binding parameter estimates from the same data. An alternative is to first generate a comprehensive standardized list of plausible models, and to then fit them exhaustively, or semi-exhaustively. Results A framework is presented in which equilibriums are modeled as pairs (g, h) where g = 0 maps total reactant concentrations (system inputs) into free reactant concentrations (system states) which h then maps into expected values of measurements (system outputs). By letting dissociation constants Kd be either freely estimated, infinity, zero, or equal to other Kd, and by letting undamaged protein fractions be either freely estimated or 1, many g models are formed. A standard space of g models for ligand-induced protein dimerization equilibria is given. Coupled to an h model, the resulting (g, h) were fitted to dTTP induced R1 dimerization data (R1 is the large subunit of ribonucleotide reductase). Models with the fewest parameters were fitted first. Thereafter, upon fitting a batch, the next batch of models (with one more parameter) was fitted only if the current batch yielded a model that was better (based on the Akaike Information Criterion) than the best model in the previous batch (with one less parameter). Within batches models were fitted in parallel. This semi-exhaustive approach yielded the same best models as an exhaustive model space fit, but in approximately one-fifth the time. Conclusion Comprehensive model space based biochemical equilibrium model selection methods are realizable. Their significance to systems biology as mappings of data into mathematical models warrants their development.
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Parkash V, Leppänen VM, Virtanen H, Jurvansuu JM, Bespalov MM, Sidorova YA, Runeberg-Roos P, Saarma M, Goldman A. The structure of the glial cell line-derived neurotrophic factor-coreceptor complex: insights into RET signaling and heparin binding. J Biol Chem 2008; 283:35164-72. [PMID: 18845535 DOI: 10.1074/jbc.m802543200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Glial cell line-derived neurotrophic factor (GDNF), a neuronal survival factor, binds its co-receptor GDNF family receptor alpha1 (GFR alpha 1) in a 2:2 ratio and signals through the receptor tyrosine kinase RET. We have solved the GDNF(2).GFR alpha 1(2) complex structure at 2.35 A resolution in the presence of a heparin mimic, sucrose octasulfate. The structure of our GDNF(2).GFR alpha 1(2) complex and the previously published artemin(2).GFR alpha 3(2) complex are unlike in three ways. First, we have experimentally identified residues that differ in the ligand-GFR alpha interface between the two structures, in particular ones that buttress the key conserved Arg(GFR alpha)-Glu(ligand)-Arg(GFR alpha) interaction. Second, the flexible GDNF ligand "finger" loops fit differently into the GFR alphas, which are rigid. Third, and we believe most importantly, the quaternary structure of the two tetramers is dissimilar, because the angle between the two GDNF monomers is different. This suggests that the RET-RET interaction differs in different ligand(2)-co-receptor(2)-RET(2) heterohexamer complexes. Consistent with this, we showed that GDNF(2).GFR alpha1(2) and artemin(2).GFR alpha 3(2) signal differently in a mitogen-activated protein kinase assay. Furthermore, we have shown by mutagenesis and enzyme-linked immunosorbent assays of RET phosphorylation that RET probably interacts with GFR alpha 1 residues Arg-190, Lys-194, Arg-197, Gln-198, Lys-202, Arg-257, Arg-259, Glu-323, and Asp-324 upon both domains 2 and 3. Interestingly, in our structure, sucrose octasulfate also binds to the Arg(190)-Lys(202) region in GFR alpha 1 domain 2. This may explain how GDNF.GFR alpha 1 can mediate cell adhesion and how heparin might inhibit GDNF signaling through RET.
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Affiliation(s)
- Vimal Parkash
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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35
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Saavedra A, Baltazar G, Duarte EP. Driving GDNF expression: the green and the red traffic lights. Prog Neurobiol 2008; 86:186-215. [PMID: 18824211 DOI: 10.1016/j.pneurobio.2008.09.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 06/18/2008] [Accepted: 09/03/2008] [Indexed: 01/28/2023]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) is widely recognized as a potent survival factor for dopaminergic neurons of the nigrostriatal pathway that degenerate in Parkinson's disease (PD). In animal models of PD, GDNF delivery to the striatum or the substantia nigra protects dopaminergic neurons against subsequent toxin-induced injury and rescues previously damaged neurons, promoting recovery of the motor function. Thus, GDNF was proposed as a potential therapy to PD aimed at slowing down, halting or reversing neurodegeneration, an issue addressed in previous reviews. However, the use of GDNF as a therapeutic agent for PD is hampered by the difficulty in delivering it to the brain. Another potential strategy is to stimulate the endogenous expression of GDNF, but in order to do that we need to understand how GDNF expression is regulated. The aim of this review is to do a comprehensive analysis of the state of the art on the control of endogenous GDNF expression in the nervous system, focusing mainly on the nigrostriatal pathway. We address the control of GDNF expression during development, in the adult brain and after injury, and how damaged neurons signal glial cells to up-regulate GDNF. Pharmacological agents or natural molecules that increase GDNF expression and show neuroprotective activity in animal models of PD are reviewed. We also provide an integrated overview of the signalling pathways linking receptors for these molecules to the induction of GDNF gene, which might also become targets for neuroprotective therapies in PD.
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Affiliation(s)
- Ana Saavedra
- Department of Cell Biology, Immunology and Neurosciences, Faculty of Medicine, University of Barcelona, Carrer Casanova 143, 08036 Barcelona, Spain.
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Abstract
Numerous important drugs target cytokines and growth factors or their receptors. Our understanding of the molecular mechanisms governing receptor activation and signaling has lagged in key areas, however, limiting drug discovery efforts to relatively few basic strategies. Recently, substantial progress has been made on several aspects of this problem. These include improved methods for establishing the mechanism of receptor activation, a clearer understanding of the biochemical basis for differential signaling by ligands that act through a common receptor, new methods for measuring the affinities of steps in receptor activation on live cells, and progress toward a systems level understanding of receptor signaling. These advances are providing a new understanding of the function of these receptors that presents opportunities for the development of improved drugs.
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Wang YQ, Bian GL, Wei LC, Cao R, Peng YF, Chen LW. Nigrostriatal neurons in rat express the glial cell line-derived neurotrophic factor receptor subunit c-RET. Anat Rec (Hoboken) 2008; 291:49-54. [PMID: 18085609 DOI: 10.1002/ar.20618] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The substantia nigra neurons expressing c-RET, a glial cell line-derived neurotrophic factor (GDNF) receptor intracellular tyrosine kinase subunit, were investigated in rats by using a double labeling method which combined retrograde horseradish peroxidase (HRP) labeling after injection into the striatum with immunohistochemistry to c-RET. It was revealed that the distribution of c-RET-immunoreactive neurons and HRP-labeled nigrostriatal neurons overlapped. Numerous double-labeled HRP/c-RET neurons were found in the substantia nigra pars compacta with predominate distribution ipsilateral to the injected striatum. Semiquantitative cell count indicated that a large percentage (97%) of HRP-labeled neurons showed c-RET immunoreactivity. Furthermore, double-labeled HRP/c-RET ones constituted only 61% of total c-RET-immunoreactive neurons in the substantia nigra ipsolateral to the injected striatum. Taken together with previous observations on glial cell line-derived neurotrophic factor in the basal ganglia, this study provides evidence that the c-RET protein may mediate biological activity of GDNF family ligands in most of projecting neurons in the substantia nigra pars compacta where the dopaminergic neurons are numerously distributed. Specially, it suggests that c-RET-mediating signaling cascades may play important roles in neuron-glial interaction that support and sustain nigrostriatal neuronal circuits in the basal ganglia.
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Affiliation(s)
- Yan-Qin Wang
- Institute of Neurosciences, The Fourth Military Medical University, Xi'an, People's Republic of China
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Gas1 reduces Ret tyrosine 1062 phosphorylation and alters GDNF‐mediated intracellular signaling. Int J Dev Neurosci 2008; 26:497-503. [DOI: 10.1016/j.ijdevneu.2008.02.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Revised: 02/18/2008] [Accepted: 02/18/2008] [Indexed: 11/22/2022] Open
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40
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Hubbard SR, Miller WT. Receptor tyrosine kinases: mechanisms of activation and signaling. Curr Opin Cell Biol 2007; 19:117-23. [PMID: 17306972 PMCID: PMC2536775 DOI: 10.1016/j.ceb.2007.02.010] [Citation(s) in RCA: 316] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Accepted: 02/07/2007] [Indexed: 12/22/2022]
Abstract
Receptor tyrosine kinases (RTKs) are essential components of signal transduction pathways that mediate cell-to-cell communication. These single-pass transmembrane receptors, which bind polypeptide ligands - mainly growth factors - play key roles in processes such as cellular growth, differentiation, metabolism and motility. Recent progress has been achieved towards an understanding of the precise (and varied) mechanisms by which RTKs are activated by ligand binding and by which signals are propagated from the activated receptors to downstream targets in the cell.
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Affiliation(s)
- Stevan R Hubbard
- Skirball Institute of Biomolecular Medicine and Department of Pharmacology, New York University School of Medicine, New York, NY 10016, USA.
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41
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Bespalov MM, Saarma M. GDNF family receptor complexes are emerging drug targets. Trends Pharmacol Sci 2007; 28:68-74. [PMID: 17218019 DOI: 10.1016/j.tips.2006.12.005] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 11/17/2006] [Accepted: 12/19/2006] [Indexed: 01/12/2023]
Abstract
Glial-cell-line-derived neurotrophic factor (GDNF) family ligands (GFLs), which consist of GDNF, neurturin, artemin and persephin, regulate the development and maintenance of the nervous system. GDNF protects and repairs dopamine-containing neurons, which degenerate in Parkinson's disease, and motoneurons, which die in amyotrophic lateral sclerosis. GDNF and neurturin have shown promise in clinical trials of Parkinson's disease, and artemin is currently undergoing clinical trials for chronic pain treatment. However, the delivery of GFLs into the brain through invasive approaches such as neurosurgery, viral vectors or by the use of encapsulated cells is associated with multiple obstacles. The development of small molecules that specifically activate GFL receptors and that can be applied systemically would overcome most of these problems. The unique nature of the GFL receptors, recent progress in elucidation of the 3D structures of GFLs and GFL-receptor complexes and the use of high-throughput screening have resulted in the development of the first small molecules that mimic the effects of the different GFLs.
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Affiliation(s)
- Maxim M Bespalov
- Institute of Biotechnology, University of Helsinki, Viikinkaari 9, PO Box 56, FIN-00014 Helsinki, Finland
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