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Thines L, Jang H, Li Z, Sayedyahossein S, Maloney R, Nussinov R, Sacks DB. Disruption of Ca 2+/calmodulin:KSR1 interaction lowers ERK activation. Protein Sci 2024; 33:e4982. [PMID: 38591710 PMCID: PMC11002989 DOI: 10.1002/pro.4982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 02/22/2024] [Accepted: 03/16/2024] [Indexed: 04/10/2024]
Abstract
KSR1, a key scaffold protein for the MAPK pathway, facilitates ERK activation upon growth factor stimulation. We recently demonstrated that KSR1 binds the Ca2+-binding protein calmodulin (CaM), thereby providing an intersection between KSR1-mediated and Ca2+ signaling. In this study, we set out to generate a KSR1 point mutant with reduced Ca2+/CaM binding in order to unravel the functional implications of their interaction. To do so, we solved the structural determinants of complex formation. Using purified fragments of KSR1, we showed that Ca2+/CaM binds to the CA3 domain of KSR1. We then used in silico molecular modeling to predict contact residues for binding. This approach identified two possible modes of interaction: (1) binding of extended Ca2+/CaM to a globular conformation of KSR1-CA3 via electrostatic interactions or (2) binding of collapsed Ca2+/CaM to α-helical KSR1-CA3 via hydrophobic interactions. Experimentally, site-directed mutagenesis of the predicted contact residues for the two binding models favored that where collapsed Ca2+/CaM binds to the α-helical conformation of KSR1-CA3. Importantly, replacing KSR1-Phe355 with Asp reduces Ca2+/CaM binding by 76%. The KSR1-F355D mutation also significantly impairs the ability of EGF to activate ERK, which reveals that Ca2+/CaM binding promotes KSR1-mediated MAPK signaling. This work, by uncovering structural insight into the binding of KSR1 to Ca2+/CaM, identifies a KSR1 single-point mutant as a bioreagent to selectively study the crosstalk between Ca2+ and KSR1-mediated signaling.
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Affiliation(s)
- Louise Thines
- Department of Laboratory MedicineNational Institutes of HealthBethesdaMarylandUSA
| | - Hyunbum Jang
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Cancer Innovation LaboratoryNational Cancer InstituteFrederickMarylandUSA
| | - Zhigang Li
- Department of Laboratory MedicineNational Institutes of HealthBethesdaMarylandUSA
| | - Samar Sayedyahossein
- Department of Laboratory MedicineNational Institutes of HealthBethesdaMarylandUSA
| | - Ryan Maloney
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Cancer Innovation LaboratoryNational Cancer InstituteFrederickMarylandUSA
| | - Ruth Nussinov
- Computational Structural Biology Section, Frederick National Laboratory for Cancer Research in the Cancer Innovation LaboratoryNational Cancer InstituteFrederickMarylandUSA
- Department of Human Molecular Genetics and BiochemistrySackler School of Medicine, Tel Aviv UniversityTel AvivIsrael
| | - David B. Sacks
- Department of Laboratory MedicineNational Institutes of HealthBethesdaMarylandUSA
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2
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Saidia AR, Ruel J, Bahloul A, Chaix B, Venail F, Wang J. Current Advances in Gene Therapies of Genetic Auditory Neuropathy Spectrum Disorder. J Clin Med 2023; 12:jcm12030738. [PMID: 36769387 PMCID: PMC9918155 DOI: 10.3390/jcm12030738] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
Auditory neuropathy spectrum disorder (ANSD) refers to a range of hearing impairments characterized by an impaired transmission of sound from the cochlea to the brain. This defect can be due to a lesion or defect in the inner hair cell (IHC), IHC ribbon synapse (e.g., pre-synaptic release of glutamate), postsynaptic terminals of the spiral ganglion neurons, or demyelination and axonal loss within the auditory nerve. To date, the only clinical treatment options for ANSD are hearing aids and cochlear implantation. However, despite the advances in hearing-aid and cochlear-implant technologies, the quality of perceived sound still cannot match that of the normal ear. Recent advanced genetic diagnostics and clinical audiology made it possible to identify the precise site of a lesion and to characterize the specific disease mechanisms of ANSD, thus bringing renewed hope to the treatment or prevention of auditory neurodegeneration. Moreover, genetic routes involving the replacement or corrective editing of mutant sequences or defected genes to repair damaged cells for the future restoration of hearing in deaf people are showing promise. In this review, we provide an update on recent discoveries in the molecular pathophysiology of genetic lesions, auditory synaptopathy and neuropathy, and gene-therapy research towards hearing restoration in rodent models and in clinical trials.
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Affiliation(s)
- Anissa Rym Saidia
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, 34295 Montpellier, France
| | - Jérôme Ruel
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, 34295 Montpellier, France
- Cognitive Neuroscience Laboratory, Aix-Marseille University, CNRS, UMR 7291, 13331 Marseille, France
| | - Amel Bahloul
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, 34295 Montpellier, France
| | - Benjamin Chaix
- Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, 34295 Montpellier, France
| | - Frédéric Venail
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, 34295 Montpellier, France
- Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, 34295 Montpellier, France
| | - Jing Wang
- Institute for Neurosciences of Montpellier (INM), University Montpellier, INSERM, 34295 Montpellier, France
- Department of ENT and Head and Neck Surgery, University Hospital of Montpellier, 34295 Montpellier, France
- Correspondence: ; Tel.: +33-499-63-60-48
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Toprak U, Hegedus D, Doğan C, Güney G. A journey into the world of insect lipid metabolism. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2020; 104:e21682. [PMID: 32335968 DOI: 10.1002/arch.21682] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/08/2020] [Accepted: 04/08/2020] [Indexed: 06/11/2023]
Abstract
Lipid metabolism is fundamental to life. In insects, it is critical, during reproduction, flight, starvation, and diapause. The coordination center for insect lipid metabolism is the fat body, which is analogous to the vertebrate adipose tissue and liver. Fat body contains various different cell types; however, adipocytes and oenocytes are the primary cells related to lipid metabolism. Lipid metabolism starts with the hydrolysis of dietary lipids, absorption of lipid monomers, followed by lipid transport from midgut to the fat body, lipogenesis or lipolysis in the fat body, and lipid transport from fat body to other sites demanding energy. Lipid metabolism is under the control of hormones, transcription factors, secondary messengers and posttranscriptional modifications. Primarily, lipogenesis is under the control of insulin-like peptides that activate lipogenic transcription factors, such as sterol regulatory element-binding proteins, whereas lipolysis is coordinated by the adipokinetic hormone that activates lipolytic transcription factors, such as forkhead box class O and cAMP-response element-binding protein. Calcium is the primary-secondary messenger affecting lipid metabolism and has different outcomes depending on the site of lipogenesis or lipolysis. Phosphorylation is central to lipid metabolism and multiple phosphorylases are involved in lipid accumulation or hydrolysis. Although most of the knowledge of insect lipid metabolism comes from the studies on the model Drosophila; other insects, in particular those with obligatory or facultative diapause, also have great potential to study lipid metabolism. The use of these models would significantly improve our knowledge of insect lipid metabolism.
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Affiliation(s)
- Umut Toprak
- Molecular Entomology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ankara University, Ankara, Turkey
| | - Dwayne Hegedus
- Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, Saskatchewan, Canada
- Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Cansu Doğan
- Molecular Entomology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ankara University, Ankara, Turkey
| | - Gözde Güney
- Molecular Entomology Laboratory, Department of Plant Protection, Faculty of Agriculture, Ankara University, Ankara, Turkey
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4
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Auditory Neuropathy Spectrum Disorders: From Diagnosis to Treatment: Literature Review and Case Reports. J Clin Med 2020; 9:jcm9041074. [PMID: 32290039 PMCID: PMC7230308 DOI: 10.3390/jcm9041074] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/21/2020] [Accepted: 04/01/2020] [Indexed: 12/21/2022] Open
Abstract
Auditory neuropathy spectrum disorder (ANSD) refers to a range of hearing impairments characterized by deteriorated speech perception, despite relatively preserved pure-tone detection thresholds. Affected individuals usually present with abnormal auditory brainstem responses (ABRs), but normal otoacoustic emissions (OAEs). These electrophysiological characteristics have led to the hypothesis that ANSD may be caused by various dysfunctions at the cochlear inner hair cell (IHC) and spiral ganglion neuron (SGN) levels, while the activity of outer hair cells (OHCs) is preserved, resulting in discrepancies between pure-tone and speech comprehension thresholds. The exact prevalence of ANSD remains unknown; clinical findings show a large variability among subjects with hearing impairment ranging from mild to profound hearing loss. A wide range of prenatal and postnatal etiologies have been proposed. The study of genetics and of the implicated sites of lesion correlated with clinical findings have also led to a better understanding of the molecular mechanisms underlying the various forms of ANSD, and may guide clinicians in better screening, assessment and treatment of ANSD patients. Besides OAEs and ABRs, audiological assessment includes stapedial reflex measurements, supraliminal psychoacoustic tests, electrocochleography (ECochG), auditory steady-state responses (ASSRs) and cortical auditory evoked potentials (CAEPs). Hearing aids are indicated in the treatment of ANSD with mild to moderate hearing loss, whereas cochlear implantation is the first choice of treatment in case of profound hearing loss, especially in case of IHC presynaptic disorders, or in case of poor auditory outcomes with conventional hearing aids.
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A Comprehensive Genome-Wide and Phenome-Wide Examination of BMI and Obesity in a Northern Nevadan Cohort. G3-GENES GENOMES GENETICS 2020; 10:645-664. [PMID: 31888951 PMCID: PMC7003082 DOI: 10.1534/g3.119.400910] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The aggregation of Electronic Health Records (EHR) and personalized genetics leads to powerful discoveries relevant to population health. Here we perform genome-wide association studies (GWAS) and accompanying phenome-wide association studies (PheWAS) to validate phenotype-genotype associations of BMI, and to a greater extent, severe Class 2 obesity, using comprehensive diagnostic and clinical data from the EHR database of our cohort. Three GWASs of 500,000 variants on the Illumina platform of 6,645 Healthy Nevada participants identified several published and novel variants that affect BMI and obesity. Each GWAS was followed with two independent PheWASs to examine associations between extensive phenotypes (incidence of diagnoses, condition, or disease), significant SNPs, BMI, and incidence of extreme obesity. The first GWAS examines associations with BMI in a cohort with no type 2 diabetics, focusing exclusively on BMI. The second GWAS examines associations with BMI in a cohort that includes type 2 diabetics. In the second GWAS, type 2 diabetes is a comorbidity, and thus becomes a covariate in the statistical model. The intersection of significant variants of these two studies is surprising. The third GWAS is a case vs. control study, with cases defined as extremely obese (Class 2 or 3 obesity), and controls defined as participants with BMI between 18.5 and 25. This last GWAS identifies strong associations with extreme obesity, including established variants in the FTO and NEGR1 genes, as well as loci not yet linked to obesity. The PheWASs validate published associations between BMI and extreme obesity and incidence of specific diagnoses and conditions, yet also highlight novel links. This study emphasizes the importance of our extensive longitudinal EHR database to validate known associations and identify putative novel links with BMI and obesity.
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Burgoyne RD, Helassa N, McCue HV, Haynes LP. Calcium Sensors in Neuronal Function and Dysfunction. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035154. [PMID: 30833454 DOI: 10.1101/cshperspect.a035154] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Calcium signaling in neurons as in other cell types can lead to varied changes in cellular function. Neuronal Ca2+ signaling processes have also become adapted to modulate the function of specific pathways over a wide variety of time domains and these can have effects on, for example, axon outgrowth, neuronal survival, and changes in synaptic strength. Ca2+ also plays a key role in synapses as the trigger for fast neurotransmitter release. Given its physiological importance, abnormalities in neuronal Ca2+ signaling potentially underlie many different neurological and neurodegenerative diseases. The mechanisms by which changes in intracellular Ca2+ concentration in neurons can bring about diverse responses is underpinned by the roles of ubiquitous or specialized neuronal Ca2+ sensors. It has been established that synaptotagmins have key functions in neurotransmitter release, and, in addition to calmodulin, other families of EF-hand-containing neuronal Ca2+ sensors, including the neuronal calcium sensor (NCS) and the calcium-binding protein (CaBP) families, play important physiological roles in neuronal Ca2+ signaling. It has become increasingly apparent that these various Ca2+ sensors may also be crucial for aspects of neuronal dysfunction and disease either indirectly or directly as a direct consequence of genetic variation or mutations. An understanding of the molecular basis for the regulation of the targets of the Ca2+ sensors and the physiological roles of each protein in identified neurons may contribute to future approaches to the development of treatments for a variety of human neuronal disorders.
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Affiliation(s)
- Robert D Burgoyne
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Nordine Helassa
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Hannah V McCue
- Centre for Genomic Research, University of Liverpool, Liverpool, United Kingdom
| | - Lee P Haynes
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
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Olguín-López N, Hérnandez-Elizárraga VH, Hernández-Matehuala R, Cruz-Hernández A, Guevara-González R, Caballero-Pérez J, Ibarra-Alvarado C, Rojas-Molina A. Impact of El Niño-Southern Oscillation 2015-2016 on the soluble proteomic profile and cytolytic activity of Millepora alcicornis ("fire coral") from the Mexican Caribbean. PeerJ 2019; 7:e6593. [PMID: 30918755 PMCID: PMC6428038 DOI: 10.7717/peerj.6593] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/09/2019] [Indexed: 12/24/2022] Open
Abstract
Reef-forming cnidarians are extremely susceptible to the “bleaching” phenomenon caused by global warming. The effect of elevated seawater temperature has been extensively studied on Anthozoans; however, to date the impact of thermal stress on the expression of genes and proteins in Hydrozoan species has not been investigated. The present study aimed to determine the differential proteomic profile of Millepora alcicornis, which inhabits the Mexican Caribbean, in response to the El Niño-Southern Oscillation 2015–2016. Additionally, the cytolytic activity of the soluble proteomes obtained from normal and bleached M. alcicornis was assessed. Bleached specimens showed decreased symbiont’s density and chlorophyll a and c2 levels. After bleaching, we observed a differential expression of 17 key proteins, tentatively identified as related to exocytosis, calcium homeostasis, cytoskeletal organization, and potential toxins, including a metalloprotease, a phospholipase A2 (PLA2), and an actitoxin. Although, some of the differentially expressed proteins included potential toxins, the hemolytic, PLA2, and proteolytic activities elicited by the soluble proteomes from bleached and normal specimens were not significantly different. The present study provides heretofore-unknown evidence that thermal stress produces a differential expression of proteins involved in essential cellular processes of Hydrozoan species. Even though our results showed an over-expression of some potential toxin-related proteins, the cytolytic effect (as assessed by hemolytic, PLA2, and caseinolytic activities) was not increased in bleached M. alcicornis, which suggests that the cytolysis is mainly produced by toxins whose expression was not affected by temperature stress. These findings allow hypothesizing that this hydrocoral is able to prey heterotrophically when suffering from moderate bleaching, giving it a better chance to withstand the effects of high temperature.
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Affiliation(s)
- Norma Olguín-López
- Posgrado en Ciencias Químico Biológicas-Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico.,Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico
| | - Víctor Hugo Hérnandez-Elizárraga
- Posgrado en Ciencias Químico Biológicas-Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico.,Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico
| | - Rosalina Hernández-Matehuala
- Posgrado en Ciencias Químico Biológicas-Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico.,Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico
| | - Andrés Cruz-Hernández
- Laboratorio de Biología Molecular-Escuela de Agronomía, Universidad De la Salle Bajío, León, Guanajuato, México
| | - Ramón Guevara-González
- C.A Ingeniería de Biosistemas-Facultad de Ingeniería-Campus Amazcala, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico
| | - Juan Caballero-Pérez
- Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico
| | - César Ibarra-Alvarado
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico
| | - Alejandra Rojas-Molina
- Laboratorio de Investigación Química y Farmacológica de Productos Naturales, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, Mexico
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Pangrsic T, Singer JH, Koschak A. Voltage-Gated Calcium Channels: Key Players in Sensory Coding in the Retina and the Inner Ear. Physiol Rev 2019; 98:2063-2096. [PMID: 30067155 DOI: 10.1152/physrev.00030.2017] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Calcium influx through voltage-gated Ca (CaV) channels is the first step in synaptic transmission. This review concerns CaV channels at ribbon synapses in primary sense organs and their specialization for efficient coding of stimuli in the physical environment. Specifically, we describe molecular, biochemical, and biophysical properties of the CaV channels in sensory receptor cells of the retina, cochlea, and vestibular apparatus, and we consider how such properties might change over the course of development and contribute to synaptic plasticity. We pay particular attention to factors affecting the spatial arrangement of CaV channels at presynaptic, ribbon-type active zones, because the spatial relationship between CaV channels and release sites has been shown to affect synapse function critically in a number of systems. Finally, we review identified synaptopathies affecting sensory systems and arising from dysfunction of L-type, CaV1.3, and CaV1.4 channels or their protein modulatory elements.
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Affiliation(s)
- Tina Pangrsic
- Synaptic Physiology of Mammalian Vestibular Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen and Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine , Göttingen, Germany ; Department of Biology, University of Maryland , College Park, Maryland ; and Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck , Innsbruck , Austria
| | - Joshua H Singer
- Synaptic Physiology of Mammalian Vestibular Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen and Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine , Göttingen, Germany ; Department of Biology, University of Maryland , College Park, Maryland ; and Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck , Innsbruck , Austria
| | - Alexandra Koschak
- Synaptic Physiology of Mammalian Vestibular Hair Cells Group, Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen and Auditory Neuroscience Group, Max Planck Institute of Experimental Medicine , Göttingen, Germany ; Department of Biology, University of Maryland , College Park, Maryland ; and Pharmacology and Toxicology, Institute of Pharmacy, University of Innsbruck , Innsbruck , Austria
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9
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Guo N, Wang G, Zong M, Han S, Liu F. Genome-wide identification, and phylogenetic and expression profiling analyses of CaM and CML genes in Brassica rapa and Brassica oleracea. Gene 2018; 677:232-244. [DOI: 10.1016/j.gene.2018.07.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 07/09/2018] [Accepted: 07/13/2018] [Indexed: 12/19/2022]
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10
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Wang W, Wan P, Lai F, Zhu T, Fu Q. Double-stranded RNA targeting calmodulin reveals a potential target for pest management of Nilaparvata lugens. PEST MANAGEMENT SCIENCE 2018; 74:1711-1719. [PMID: 29381254 DOI: 10.1002/ps.4865] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 01/03/2018] [Accepted: 01/11/2018] [Indexed: 06/07/2023]
Abstract
BACKGROUND Calmodulin (CaM) is an essential protein in cellular activity and plays important roles in many processes in insect development. RNA interference (RNAi) has been hypothesized to be a promising method for pest control. CaM is a good candidate for RNAi target. However, the sequence and function of CaM in Nilaparvata lugens are unknown. Furthermore, the double-stranded RNA (dsRNA) target to CaM gene in pest control is still unavailable. RESULTS In the present study, two alternatively spliced variants of CaM transcripts, designated NlCaM1 and NlCaM2, were cloned from N. lugens. The two cDNA sequences exhibited 100% identity to each other in the open reading frame (ORF), and only differed in the 3' untranslated region (UTR). NlCaM including NlCaM1 and NlCaM2 mRNA was detectable in all developmental stages and tissues of N. lugens, with significantly increased expression in the salivary glands. Knockdown of NlCaM expression by RNAi with different dsRNAs led to an inability to molt properly, increased mortality, which ranged from 49.7 to 92.5%, impacted development of the ovaries and led to female infertility. There were no significant reductions in the transcript levels of vitellogenin and its receptor or in the total vitellogenin protein level relative to the control group. However, a significant reduction in vitellogenin protein was detected in ovaries injected with dsNlCaM. In addition, a specific dsRNA of NlCaM for control of N. lugens was designed and tested. CONCLUSION NlCaM plays important roles mainly in nymph development and uptake of vitellogenin by ovaries in vitellogenesis in N. lugens. dsRNA derived from the less conserved 3'-UTR of NlCaM shows great potential for RNAi-based N. lugens management. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Weixia Wang
- State Key Lab of Rice Biology, China Rice Research Institute, Hangzhou, Zhejiang, China
| | - Pinjun Wan
- State Key Lab of Rice Biology, China Rice Research Institute, Hangzhou, Zhejiang, China
| | - Fengxiang Lai
- State Key Lab of Rice Biology, China Rice Research Institute, Hangzhou, Zhejiang, China
| | - Tingheng Zhu
- College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang, China
| | - Qiang Fu
- State Key Lab of Rice Biology, China Rice Research Institute, Hangzhou, Zhejiang, China
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11
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Yang T, Britt JK, Cintrón-Pérez CJ, Vázquez-Rosa E, Tobin KV, Stalker G, Hardie J, Taugher RJ, Wemmie J, Pieper AA, Lee A. Ca 2+-Binding Protein 1 Regulates Hippocampal-dependent Memory and Synaptic Plasticity. Neuroscience 2018; 380:90-102. [PMID: 29660444 DOI: 10.1016/j.neuroscience.2018.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 03/16/2018] [Accepted: 04/05/2018] [Indexed: 11/25/2022]
Abstract
Ca2+-binding protein 1 (CaBP1) is a Ca2+-sensing protein similar to calmodulin that potently regulates voltage-gated Ca2+ channels. Unlike calmodulin, however, CaBP1 is mainly expressed in neuronal cell-types and enriched in the hippocampus, where its function is unknown. Here, we investigated the role of CaBP1 in hippocampal-dependent behaviors using mice lacking expression of CaBP1 (C-KO). By western blot, the largest CaBP1 splice variant, caldendrin, was detected in hippocampal lysates from wild-type (WT) but not C-KO mice. Compared to WT mice, C-KO mice exhibited mild deficits in spatial learning and memory in both the Barnes maze and in Morris water maze reversal learning. In contextual but not cued fear-conditioning assays, C-KO mice showed greater freezing responses than WT mice. In addition, the number of adult-born neurons in the hippocampus of C-KO mice was ∼40% of that in WT mice, as measured by bromodeoxyuridine labeling. Moreover, hippocampal long-term potentiation was significantly reduced in C-KO mice. We conclude that CaBP1 is required for cellular mechanisms underlying optimal encoding of hippocampal-dependent spatial and fear-related memories.
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Affiliation(s)
- Tian Yang
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Neurology, University of Iowa, Iowa City, IA 52242, USA
| | - Jeremiah K Britt
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Psychiatry, University of Iowa, Iowa City, IA 52242, USA
| | - Coral J Cintrón-Pérez
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Psychiatry, University of Iowa, Iowa City, IA 52242, USA
| | - Edwin Vázquez-Rosa
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Psychiatry, University of Iowa, Iowa City, IA 52242, USA
| | - Kevin V Tobin
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Neurology, University of Iowa, Iowa City, IA 52242, USA
| | - Grant Stalker
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Neurology, University of Iowa, Iowa City, IA 52242, USA
| | - Jason Hardie
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Neurology, University of Iowa, Iowa City, IA 52242, USA
| | - Rebecca J Taugher
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Psychiatry, University of Iowa, Iowa City, IA 52242, USA
| | - John Wemmie
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Psychiatry, University of Iowa, Iowa City, IA 52242, USA
| | - Andrew A Pieper
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Neurology, University of Iowa, Iowa City, IA 52242, USA; Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Psychiatry, University of Iowa, Iowa City, IA 52242, USA; Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Free Radical, University of Iowa, Iowa City, IA 52242, USA; Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Radiation Biology Program, University of Iowa, Iowa City, IA 52242, USA; Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Radiation Oncology Comprehensive Cancer Center, University of Iowa, Iowa City, IA 52242, USA; Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Veterans Affairs, University of Iowa, Iowa City, IA 52242, USA; Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Pappajohn Biomedical Institute and Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA
| | - Amy Lee
- Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, Neurology, University of Iowa, Iowa City, IA 52242, USA.
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12
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Wang N, Zhong X, Song X, Gu X, Lai W, Xie Y, Peng X, Yang G. Molecular and biochemical characterization of calmodulin from Echinococcus granulosus. Parasit Vectors 2017; 10:597. [PMID: 29202858 PMCID: PMC5716380 DOI: 10.1186/s13071-017-2545-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 11/21/2017] [Indexed: 11/10/2022] Open
Abstract
Background Echinococcus granulosus is a harmful cestode parasite that causes cystic echinococcosis in humans as well as various livestock species and wild animals. Calmodulin (CaM), a Ca2+ sensor protein, is widely expressed in eukaryotes and mediates a variety of cellular signaling activities. Methods In the present study, the cDNA encoding CaM in Echinococcus granulosus (rEgCaM) was successfully cloned and the molecular and biochemical characterizations carried out. The antigenicity and immunoreactivity of rEgCaM was detected and the preliminary enzyme-linked immunosorbent assay (ELISA)-based serodiagnostic potential of EgCaM was assessed. The locations of this protein in the adult worm and larval stage, and the mRNA expression in different states of E. granulosus protoscoleces (PSCs) were defined clearly. Moreover, the Ca2+-binding properties of EgCaM were measured. Results rEgCaM is a highly conserved calcium-binding protein, consisting of 149 amino acids. Immunoblotting analysis revealed that rEgCaM could be identified using E. granulosus infected sheep serum. The use of rEgCaM as an antigen was evaluated by indirect ELISA which exhibited a high sensitivity (90.3%), but low specificity (47.1%). rEgCaM was ubiquitously expressed in protoscoleces and adults of E. granulosus, as well as in the germinal layer of the cyst wall. The mRNA expression level of rEgCaM was increased from the start of H2O2 exposure and then gradually decreased because of the increased apoptosis of PSCs. In electrophoretic mobility tests and 1-anilinonaphthalene-8-sulfonic acid assays, rEgCaM showed a typical characteristic of a calcium-binding protein. Conclusions To our knowledge, this is the first report on CaM from E. granulosus and rEgCaM is likely to be involved in some important biological function of E. granulosus as a calcium-binding protein.
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Affiliation(s)
- Ning Wang
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xiuqin Zhong
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xingju Song
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xiaobin Gu
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Weiming Lai
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yue Xie
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xuerong Peng
- Department of Chemistry, College of Life and Basic Science, Sichuan Agricultural University, Chengdu, 611130, China
| | - Guangyou Yang
- Department of Parasitology, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.
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13
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He R, Shen N, Lin H, Gu X, Lai W, Peng X, Yang G. Molecular characterization of calmodulin from Sarcoptes scabiei. Parasitol Int 2017; 66:1-6. [DOI: 10.1016/j.parint.2016.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/18/2016] [Accepted: 11/09/2016] [Indexed: 12/13/2022]
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14
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Ababou A, Zaleska M, Pfuhl M. On the Ca 2+ binding and conformational change in EF-hand domains: Experimental evidence of Ca 2+-saturated intermediates of N-domain of calmodulin. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:640-651. [PMID: 28288938 DOI: 10.1016/j.bbapap.2017.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 03/07/2017] [Accepted: 03/09/2017] [Indexed: 02/07/2023]
Abstract
Double mutation of Q41L and K75I in the N-domain of calmodulin (N-Cam) stabilizes the closed form of N-Cam such that binding of Ca2+ in solution no longer triggers a conformational change to the open form, and its Ca2+ binding affinity decreases dramatically. To further investigate the solvation effects on the structure, Ca2+ binding affinity and conformational dynamics of this N-Cam double mutant in the Ca2+ saturated state, we solved its X-ray structure. Surprisingly, the structure revealed an open conformation of the domain which contradicts its closed conformation in solution. Here we provide evidence that crystallization conditions were responsible for this Ca2+-saturated domain open conformation in the crystal. Importantly, we demonstrate that the presence of the crystallization co-precipitant and alcohols were able to induce a progressive opening of the closed form of this domain, in Ca2+ saturated state, in solution. However, in the Ca2+ depleted state, addition of alcohols was unable to induce any opening of this domain in solution. In addition, in the Ca2+ saturated state, the molecular dynamics simulations show that while N-Cam can populate the open and closed conformation, the N-Cam double mutant exclusively populates the closed conformation. Our results provide experimental evidence of intermediate conformations of Ca2+-saturated N-Cam in solution. We propose that conformational change of Ca2+ sensor EF-hand domains depends on solvation energetics, Ca2+ binding to promote the full open form, Ca2+ depleted state conformational dynamics, and the chemical properties of the molecules nearby key residues such as those at positions 41 and 75 in N-Cam.
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Affiliation(s)
- Abdessamad Ababou
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK; University of East London, School of Health, Sport and Bioscience, Water Lane, London E15 4LZ, UK.
| | - Mariola Zaleska
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - Mark Pfuhl
- Cardiovascular and Randall Division, King's College London, London SE1 1UL, UK
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15
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Westerlind H, Mellander MR, Bresso F, Munch A, Bonfiglio F, Assadi G, Rafter J, Hübenthal M, Lieb W, Källberg H, Brynedal B, Padyukov L, Halfvarson J, Törkvist L, Bjork J, Andreasson A, Agreus L, Almer S, Miehlke S, Madisch A, Ohlsson B, Löfberg R, Hultcrantz R, Franke A, D'Amato M. Dense genotyping of immune-related loci identifies HLA variants associated with increased risk of collagenous colitis. Gut 2017; 66:421-428. [PMID: 26525574 DOI: 10.1136/gutjnl-2015-309934] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 10/11/2015] [Accepted: 10/12/2015] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Collagenous colitis (CC) is a major cause of chronic non-bloody diarrhoea, particularly in the elderly female population. The aetiology of CC is unknown, and still poor is the understanding of its pathogenesis. This possibly involves dysregulated inflammation and immune-mediated reactions in genetically predisposed individuals, but the contribution of genetic factors to CC is underinvestigated. We systematically tested immune-related genes known to impact the risk of several autoimmune diseases for their potential CC-predisposing role. DESIGN Three independent cohorts of histologically confirmed CC cases (N=314) and controls (N=4299) from Sweden and Germany were included in a 2-step association analysis. Immunochip and targeted single nucleotide polymorphism (SNP) genotype data were produced, respectively, for discovery and replication purposes. Classical human leucocyte antigen (HLA) variants at 2-digit and 4-digit resolution were obtained via imputation from single marker genotypes. SNPs and HLA variants passing quality control filters were tested for association with CC with logistic regression adjusting for age, sex and country of origin. RESULTS Forty-two markers gave rise to genome-wide significant association signals, all contained within the HLA region on chromosome 6 (best p=4.2×10-10 for SNP rs4143332). Among the HLA variants, most pronounced risk effects were observed for 8.1 haplotype alleles including DQ2.5, which was targeted and confirmed in the replication data set (p=2.3×10-11; OR=2.06; 95% CI (1.67 to 2.55) in the combined analysis). CONCLUSIONS HLA genotype associates with CC, thus implicating HLA-related immune mechanisms in its pathogenesis.
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Affiliation(s)
- Helga Westerlind
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Marie-Rose Mellander
- Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Gastrocentrum, Karolinska University Hospital, Stockholm, Sweden
| | - Francesca Bresso
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
- Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Gastrocentrum, Karolinska University Hospital, Stockholm, Sweden
| | - Andreas Munch
- Department of Clinical and Experimental Medicine, Faculty of Health Science, Linköpings University, Linköping, Sweden
| | - Ferdinando Bonfiglio
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Ghazaleh Assadi
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Joseph Rafter
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
| | - Matthias Hübenthal
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Wolfgang Lieb
- Institute of Epidemiology and Biobank POPGEN, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Henrik Källberg
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Boel Brynedal
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Leonid Padyukov
- Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Jonas Halfvarson
- Department of Gastroenterology, Faculty of Medicine and Health, Örebro University, Örebro, Sweden
| | - Leif Törkvist
- Gastrocentrum, Karolinska University Hospital, Stockholm, Sweden
| | - Jan Bjork
- Gastrocentrum, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Andreasson
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Lars Agreus
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Sven Almer
- Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Gastrocentrum, Karolinska University Hospital, Stockholm, Sweden
| | - Stephan Miehlke
- Center for Digestive Diseases, Internal Medicine Center Eppendorf, Hamburg, Germany
| | - Ahmed Madisch
- Clinic for Gastroenterology, Endoscopy and Interventional Diabetology, Siloah Hospital, Hannover, Germany
| | - Bodil Ohlsson
- Department of Clinical Sciences, Skåne University Hospital, Lund University, Lund, Sweden
| | - Robert Löfberg
- Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- Sophiahemmet Hospital, Stockholm, Sweden
| | - Rolf Hultcrantz
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Mauro D'Amato
- Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm, Sweden
- BioCruces Health Research Institute and IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
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16
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Ca 2+-binding protein 2 inhibits Ca 2+-channel inactivation in mouse inner hair cells. Proc Natl Acad Sci U S A 2017; 114:E1717-E1726. [PMID: 28183797 DOI: 10.1073/pnas.1617533114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Ca2+-binding protein 2 (CaBP2) inhibits the inactivation of heterologously expressed voltage-gated Ca2+ channels of type 1.3 (CaV1.3) and is defective in human autosomal-recessive deafness 93 (DFNB93). Here, we report a newly identified mutation in CABP2 that causes a moderate hearing impairment likely via nonsense-mediated decay of CABP2-mRNA. To study the mechanism of hearing impairment resulting from CABP2 loss of function, we disrupted Cabp2 in mice (Cabp2LacZ/LacZ ). CaBP2 was expressed by cochlear hair cells, preferentially in inner hair cells (IHCs), and was lacking from the postsynaptic spiral ganglion neurons (SGNs). Cabp2LacZ/LacZ mice displayed intact cochlear amplification but impaired auditory brainstem responses. Patch-clamp recordings from Cabp2LacZ/LacZ IHCs revealed enhanced Ca2+-channel inactivation. The voltage dependence of activation and the number of Ca2+ channels appeared normal in Cabp2LacZ/LacZ mice, as were ribbon synapse counts. Recordings from single SGNs showed reduced spontaneous and sound-evoked firing rates. We propose that CaBP2 inhibits CaV1.3 Ca2+-channel inactivation, and thus sustains the availability of CaV1.3 Ca2+ channels for synaptic sound encoding. Therefore, we conclude that human deafness DFNB93 is an auditory synaptopathy.
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17
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Morrill GA, Kostellow AB, Gupta RK. Computational comparison of a calcium-dependent jellyfish protein (apoaequorin) and calmodulin-cholesterol in short-term memory maintenance. Neurosci Lett 2017; 642:113-118. [PMID: 28159636 DOI: 10.1016/j.neulet.2017.01.069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/15/2017] [Accepted: 01/30/2017] [Indexed: 12/21/2022]
Abstract
Memory reconsolidation and maintenance depend on calcium channels and on calcium/calmodulin-dependent kinases regulating protein turnover in the hippocampus. Ingestion of a jellyfish protein, apoaequorin, reportedly protects and/or improves verbal learning in adults and is currently widely advertised for use by the elderly. Apoaequorin is a member of the EF-hand calcium binding family of proteins that includes calmodulin. Calmodulin-1 (148 residues) differs from Apoaequorin (195 residues) in that it contains four rather than three Ca2+-binding sites and three rather than four cholesterol-binding (CRAC, CARC) domains. All three cholesterol-binding CARC domains in calmodulin have a high interaction affinity for cholesterol compared to only two high affinity CARC domains in apoaequorin. Both calmodulin and apoaequorin can form dimers with a potential of eight bound Ca2+ ions and six high affinity-bound cholesterol molecules in calmodulin with six bound Ca2+ ions and a mixed population of eight cholesterols bound to both CARC and CRAC domains in apoaqueorin. MEMSAT-SVM analysis indicates that both calmodulin and apoaqueorin have a pore-lining region. The Peptide-Cutter algorithm predicts that calmodulin-1 contains 11 trypsin-specific cleavage sites (compared to 21 in apoaqueorin), four of which are potentially blocked by cholesterol and three are within the Ca-binding domains and/or the pore-lining region. Three are clustered between the third and fourth Ca2+-binding sites. Only calmodulin pore-lining regions contain Ca2+ binding sites and as dimers may insert into the plasma membrane of neural cells and act as Ca2+ channels. In a dietary supplement, bound cholesterol may protect both apoaequorin and calmodulin from proteolysis in the gut as well as facilitate uptake across the blood-brain barrier. Our results suggest that a physiological calmodulin-cholesterol complex, not cholesterol-free jellyfish protein, may better serve as a dietary supplement to facilitate memory maintenance.
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Affiliation(s)
- Gene A Morrill
- Department of Physiology & Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA.
| | - Adele B Kostellow
- Department of Physiology & Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
| | - Raj K Gupta
- Department of Physiology & Biophysics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY, 10461, USA
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18
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Jing P, Zou J, Kong L, Hu S, Wang B, Yang J, Xie G. OsCCD1, a novel small calcium-binding protein with one EF-hand motif, positively regulates osmotic and salt tolerance in rice. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2016; 247:104-14. [PMID: 27095404 DOI: 10.1016/j.plantsci.2016.03.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 03/16/2016] [Accepted: 03/19/2016] [Indexed: 05/20/2023]
Abstract
Calcium-binding proteins play key roles in the signal transduction in the growth and stress response in eukaryotes. However, a subfamily of proteins with one EF-hand motif has not been fully studied in higher plants. Here, a novel small calcium-binding protein with a C-terminal centrin-like domain (CCD1) in rice, OsCCD1, was characterized to show high similarity with a TaCCD1 in wheat. As a result, OsCCD1 can bind Ca(2+) in the in vitro EMSA and the fluorescence staining calcium-binding assays. Transient expression of green fluorescent protein (GFP)-tagged OsCCD1 in rice protoplasts showed that OsCCD1 was localized in the nucleus and cytosol of rice cells. OsCCD1 transcript levels were transiently induced by osmotic stress and salt stress through the calcium-mediated ABA signal. The rice seedlings of T-DNA mutant lines showed significantly less tolerance to osmotic and salt stresses than wild type plants (p<0.01). Conversely, its overexpressors can significantly enhance the tolerance to osmotic and salt stresses than wild type plants (p<0.05). Semi-quantitative RT-PCR analysis revealed that, OsDREB2B, OsAPX1 and OsP5CS genes are involved in the rice tolerance to osmotic and salt stresses. In sum, OsCCD1 gene probably affects the DREB2B and its downstream genes to positively regulate osmotic and salt tolerance in rice seedlings.
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Affiliation(s)
- Pei Jing
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Juanzi Zou
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Lin Kong
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Shiqi Hu
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Biying Wang
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Jun Yang
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Guosheng Xie
- MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
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19
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Yang T, Scholl ES, Pan N, Fritzsch B, Haeseleer F, Lee A. Expression and Localization of CaBP Ca2+ Binding Proteins in the Mouse Cochlea. PLoS One 2016; 11:e0147495. [PMID: 26809054 PMCID: PMC4725724 DOI: 10.1371/journal.pone.0147495] [Citation(s) in RCA: 18] [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: 10/28/2015] [Accepted: 01/05/2016] [Indexed: 11/19/2022] Open
Abstract
CaBPs are a family of EF-hand Ca2+ binding proteins that are structurally similar to calmodulin. CaBPs can interact with, and yet differentially modulate, effectors that are regulated by calmodulin, such as Cav1 voltage-gated Ca2+ channels. Immunolabeling studies suggest that multiple CaBP family members (CaBP1, 2, 4, and 5) are expressed in the cochlea. To gain insights into the respective auditory functions of these CaBPs, we characterized the expression and cellular localization of CaBPs in the mouse cochlea. By quantitative reverse transcription PCR, we show that CaBP1 and CaBP2 are the major CaBPs expressed in mouse cochlea both before and after hearing onset. Of the three alternatively spliced variants of CaBP1 (caldendrin, CaBP1-L, and CaBP1-S) and CaBP2 (CaBP2-alt, CaBP2-L, CaBP2-S), caldendrin and CaBP2-alt are the most abundant. By in situ hybridization, probes recognizing caldendrin strongly label the spiral ganglion, while probes designed to recognize all three isoforms of CaBP1 weakly label both the inner and outer hair cells as well as the spiral ganglion. Within the spiral ganglion, caldendrin/CaBP1 labeling is associated with cells resembling satellite glial cells. CaBP2-alt is strongly expressed in inner hair cells both before and after hearing onset. Probes designed to recognize all three variants of CaBP2 strongly label inner hair cells before hearing onset and outer hair cells after the onset of hearing. Thus, CaBP1 and CaBP2 may have overlapping roles in regulating Ca2+ signaling in the hair cells, and CaBP1 may have an additional function in the spiral ganglion. Our findings provide a framework for understanding the role of CaBP family members in the auditory periphery.
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Affiliation(s)
- Tian Yang
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States of America
- Department of Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, Iowa, United States of America
- Department of Neurology, University of Iowa, Iowa City, Iowa, United States of America
| | - Elizabeth S. Scholl
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States of America
- Department of Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, Iowa, United States of America
- Department of Neurology, University of Iowa, Iowa City, Iowa, United States of America
| | - Ning Pan
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - Bernd Fritzsch
- Department of Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, Iowa, United States of America
- Department of Biology, University of Iowa, Iowa City, Iowa, United States of America
| | - Françoise Haeseleer
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington, United States of America
| | - Amy Lee
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa, United States of America
- Department of Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, Iowa, United States of America
- Department of Neurology, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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20
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Electrostatics effects on Ca(2+) binding and conformational changes in EF-hand domains: Functional implications for EF-hand proteins. Arch Biochem Biophys 2015; 587:61-9. [PMID: 26494044 DOI: 10.1016/j.abb.2015.10.011] [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: 09/07/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 12/11/2022]
Abstract
Mutations of Gln41 and Lys75 with nonpolar residues in the N-terminal domain of calmodulin (N-Cam) revealed the importance of solvation energetics in conformational change of Ca(2+) sensor EF-hand domains. While in general these domains have polar residues at these corresponding positions yet the extent of their conformational response to Ca(2+) binding and their Ca(2+) binding affinity can be different from N-Cam. Consequently, here we address the charge state of the polar residues at these positions. The results show that the charge state of these polar residues can affect substantially the conformational change and the Ca(2+) binding affinity of our N-Cam variants. Since all the variants kept their conformational activity in the presence of Ca(2+) suggests that the differences observed among them mainly originate from the difference in their molecular dynamics. Hence we propose that the molecular dynamics of Ca(2+) sensor EF-hand domains is a key factor in the multifunctional aspect of EF-hand proteins.
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21
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Bauer NC, Doetsch PW, Corbett AH. Mechanisms Regulating Protein Localization. Traffic 2015; 16:1039-61. [PMID: 26172624 DOI: 10.1111/tra.12310] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 07/08/2015] [Accepted: 07/08/2015] [Indexed: 12/23/2022]
Abstract
Cellular functions are dictated by protein content and activity. There are numerous strategies to regulate proteins varying from modulating gene expression to post-translational modifications. One commonly used mode of regulation in eukaryotes is targeted localization. By specifically redirecting the localization of a pool of existing protein, cells can achieve rapid changes in local protein function. Eukaryotic cells have evolved elegant targeting pathways to direct proteins to the appropriate cellular location or locations. Here, we provide a general overview of these localization pathways, with a focus on nuclear and mitochondrial transport, and present a survey of the evolutionarily conserved regulatory strategies identified thus far. We end with a description of several specific examples of proteins that exploit localization as an important mode of regulation.
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Affiliation(s)
- Nicholas C Bauer
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Graduate Program in Biochemistry, Cell, and Developmental Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.,Current address: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Paul W Doetsch
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322, USA.,Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.,Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.,Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA 30322, USA
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Mauceri D, Hagenston AM, Schramm K, Weiss U, Bading H. Nuclear Calcium Buffering Capacity Shapes Neuronal Architecture. J Biol Chem 2015; 290:23039-49. [PMID: 26231212 DOI: 10.1074/jbc.m115.654962] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Indexed: 12/20/2022] Open
Abstract
Calcium-binding proteins (CaBPs) such as parvalbumin are part of the cellular calcium buffering system that determines intracellular calcium diffusion and influences the spatiotemporal dynamics of calcium signals. In neurons, CaBPs are primarily localized to the cytosol and function, for example, in nerve terminals in short-term synaptic plasticity. However, CaBPs are also expressed in the cell nucleus, suggesting that they modulate nuclear calcium signals, which are key regulators of neuronal gene expression. Here we show that the calcium buffering capacity of the cell nucleus in mouse hippocampal neurons regulates neuronal architecture by modulating the expression levels of VEGFD and the complement factor C1q-c, two nuclear calcium-regulated genes that control dendrite geometry and spine density, respectively. Increasing the levels of nuclear calcium buffers by means of expression of a nuclearly targeted form of parvalbumin fused to mCherry (PV.NLS-mC) led to a reduction in VEGFD expression and, as a result, to a decrease in total dendritic length and complexity. In contrast, mRNA levels of the synapse pruning factor C1q-c were increased in neurons expressing PV.NLS-mC, causing a reduction in the density and size of dendritic spines. Our results establish a close link between nuclear calcium buffering capacity and the transcription of genes that determine neuronal structure. They suggest that the development of cognitive deficits observed in neurological conditions associated with CaBP deregulation may reflect the loss of necessary structural features of dendrites and spines.
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Affiliation(s)
- Daniela Mauceri
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Anna M Hagenston
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Kathrin Schramm
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Ursula Weiss
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
| | - Hilmar Bading
- From the Department of Neurobiology, Interdisciplinary Centre for Neurosciences, University of Heidelberg, INF 364, 69120 Heidelberg, Germany
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Yan J, Leal K, Magupalli VG, Nanou E, Martinez GQ, Scheuer T, Catterall WA. Modulation of CaV2.1 channels by neuronal calcium sensor-1 induces short-term synaptic facilitation. Mol Cell Neurosci 2015; 63:124-31. [PMID: 25447945 DOI: 10.1016/j.mcn.2014.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 10/29/2014] [Accepted: 11/03/2014] [Indexed: 12/01/2022] Open
Abstract
Facilitation and inactivation of P/Q-type Ca2+ currents mediated by Ca2+/calmodulin binding to Ca(V)2.1 channels contribute to facilitation and rapid depression of synaptic transmission, respectively. Other calcium sensor proteins displace calmodulin from its binding site and differentially modulate P/Q-type Ca2 + currents, resulting in diverse patterns of short-term synaptic plasticity. Neuronal calcium sensor-1 (NCS-1, frequenin) has been shown to enhance synaptic facilitation, but the underlying mechanism is unclear. We report here that NCS-1 directly interacts with IQ-like motif and calmodulin-binding domain in the C-terminal domain of Ca(V)2.1 channel. NCS-1 reduces Ca2 +-dependent inactivation of P/Q-type Ca2+ current through interaction with the IQ-like motif and calmodulin-binding domain without affecting peak current or activation kinetics. Expression of NCS-1 in presynaptic superior cervical ganglion neurons has no effect on synaptic transmission, eliminating effects of this calcium sensor protein on endogenous N-type Ca2+ currents and the endogenous neurotransmitter release machinery. However, in superior cervical ganglion neurons expressing wild-type Ca(V)2.1 channels, co-expression of NCS-1 induces facilitation of synaptic transmission in response to paired pulses and trains of depolarizing stimuli, and this effect is lost in Ca(V)2.1 channels with mutations in the IQ-like motif and calmodulin-binding domain. These results reveal that NCS-1 directly modulates Ca(V)2.1 channels to induce short-term synaptic facilitation and further demonstrate that CaS proteins are crucial in fine-tuning short-term synaptic plasticity.
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Abstract
Ca2+-dependent inactivation (CDI) is a negative feedback regulation of voltage-gated Cav1 and Cav2 channels that is mediated by the Ca2+ sensing protein, calmodulin (CaM), binding to the pore-forming Cav α1 subunit. David Yue and his colleagues made seminal contributions to our understanding of this process, as well as factors that regulate CDI. Important in this regard are members of a family of Ca2+ binding proteins (CaBPs) that are related to calmodulin. CaBPs are expressed mainly in neural tissues and can antagonize CaM-dependent CDI for Cav1 L-type channels. This review will focus on the roles of CaBPs as Cav1-interacting proteins, and the significance of these interactions for vision, hearing, and neuronal Ca2+ signaling events.
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Affiliation(s)
- Jason Hardie
- a Departments of Molecular Physiology and Biophysics ; Otolaryngology-Head and Neck Surgery and Neurology; University of Iowa ; Iowa City , IA USA
| | - Amy Lee
- a Departments of Molecular Physiology and Biophysics ; Otolaryngology-Head and Neck Surgery and Neurology; University of Iowa ; Iowa City , IA USA
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25
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Congenital stationary night blindness: An analysis and update of genotype–phenotype correlations and pathogenic mechanisms. Prog Retin Eye Res 2015; 45:58-110. [DOI: 10.1016/j.preteyeres.2014.09.001] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/25/2014] [Accepted: 09/30/2014] [Indexed: 01/18/2023]
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26
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Guanylate Cyclase-Activating Protein-2 Undergoes Structural Changes upon Binding to Detergent Micelles and Bicelles. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2767-77. [DOI: 10.1016/j.bbamem.2014.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 11/23/2022]
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27
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Palczewski K. Chemistry and biology of the initial steps in vision: the Friedenwald lecture. Invest Ophthalmol Vis Sci 2014; 55:6651-72. [PMID: 25338686 DOI: 10.1167/iovs.14-15502] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Visual transduction is the process in the eye whereby absorption of light in the retina is translated into electrical signals that ultimately reach the brain. The first challenge presented by visual transduction is to understand its molecular basis. We know that maintenance of vision is a continuous process requiring the activation and subsequent restoration of a vitamin A-derived chromophore through a series of chemical reactions catalyzed by enzymes in the retina and retinal pigment epithelium (RPE). Diverse biochemical approaches that identified key proteins and reactions were essential to achieve a mechanistic understanding of these visual processes. The three-dimensional arrangements of these enzymes' polypeptide chains provide invaluable insights into their mechanisms of action. A wealth of information has already been obtained by solving high-resolution crystal structures of both rhodopsin and the retinoid isomerase from pigment RPE (RPE65). Rhodopsin, which is activated by photoisomerization of its 11-cis-retinylidene chromophore, is a prototypical member of a large family of membrane-bound proteins called G protein-coupled receptors (GPCRs). RPE65 is a retinoid isomerase critical for regeneration of the chromophore. Electron microscopy (EM) and atomic force microscopy have provided insights into how certain proteins are assembled to form much larger structures such as rod photoreceptor cell outer segment membranes. A second challenge of visual transduction is to use this knowledge to devise therapeutic approaches that can prevent or reverse conditions leading to blindness. Imaging modalities like optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) applied to appropriate animal models as well as human retinal imaging have been employed to characterize blinding diseases, monitor their progression, and evaluate the success of therapeutic agents. Lately two-photon (2-PO) imaging, together with biochemical assays, are revealing functional aspects of vision at a new molecular level. These multidisciplinary approaches combined with suitable animal models and inbred mutant species can be especially helpful in translating provocative cell and tissue culture findings into therapeutic options for further development in animals and eventually in humans. A host of different approaches and techniques is required for substantial progress in understanding fundamental properties of the visual system.
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Affiliation(s)
- Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
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Prokosch V, Chiwitt C, Rose K, Thanos S. Deciphering proteins and their functions in the regenerating retina. Expert Rev Proteomics 2014; 7:775-95. [DOI: 10.1586/epr.10.47] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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29
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Visser D, Langeslag M, Kedziora KM, Klarenbeek J, Kamermans A, Horgen FD, Fleig A, van Leeuwen FN, Jalink K. TRPM7 triggers Ca2+ sparks and invadosome formation in neuroblastoma cells. Cell Calcium 2013; 54:404-15. [PMID: 24176224 DOI: 10.1016/j.ceca.2013.09.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/27/2013] [Accepted: 09/28/2013] [Indexed: 11/28/2022]
Abstract
Cell migration depends on the dynamic formation and turnover of cell adhesions and is tightly controlled by actomyosin contractility and local Ca2+ signals. The divalent cation channel TRPM7 (Transient Receptor Potential cation channel, subfamily Melastatin, member 7) has recently received much attention as a regulator of cell adhesion, migration and (localized) Ca2+ signaling. Overexpression and knockdown of TRPM7 affects actomyosin contractility and the formation of cell adhesions such as invadosomes and focal adhesions, but the role of TRPM7-mediated Ca2+ signals herein is currently not understood. Using Total Internal Reflection Fluorescence (TIRF) Ca2+ fluorometry and a novel automated analysis routine we have addressed the role of Ca2+ in the control of invadosome dynamics in N1E-115 mouse neuroblastoma cells. We find that TRPM7 promotes the formation of highly repetitive and localized Ca2+ microdomains or "Ca2+ sparking hotspots" at the ventral plasma membrane. Ca2+ sparking appears strictly dependent on extracellular Ca2+ and is abolished by TRPM7 channel inhibitors such as waixenicin-A. TRPM7 inhibition also induces invadosome dissolution. However, invadosome formation is (functionally and spatially) dissociated from TRPM7-mediated Ca2+ sparks. Rather, our data indicate that TRPM7 affects actomyosin contractility and invadosome formation independent of Ca2+ influx.
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Affiliation(s)
- Daan Visser
- Division of Cell Biology I, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands
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30
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Tyson JR, Snutch TP. Molecular nature of voltage‐gated calcium channels: structure and species comparison. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/wmts.91] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- John R. Tyson
- Michael Smith Laboratories University of British Columbia Vancouver BC Canada
| | - Terrance P. Snutch
- Michael Smith Laboratories University of British Columbia Vancouver BC Canada
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31
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Structural Biology of a Major Signaling Network that Regulates Plant Abiotic Stress: The CBL-CIPK Mediated Pathway. Int J Mol Sci 2013; 14:5734-49. [PMID: 23481636 PMCID: PMC3634423 DOI: 10.3390/ijms14035734] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 02/27/2013] [Accepted: 02/28/2013] [Indexed: 01/17/2023] Open
Abstract
The Arabidopsis SOS2 family of twenty-six protein kinases (CIPKs), their interacting activators, the SOS3 family of ten calcium-binding proteins (CBLs) and protein phosphatases type 2C (PP2C), function together in decoding calcium signals elicited by different environmental stimuli. Biochemical data suggest that stable CBL-CIPK or CIPK-PP2C complexes may be regulating the activity of various substrates controlling ion homeostasis. The available structural information provides a general regulatory mechanism in which calcium perception by CBLs and kinase activation is coupled. The structural basis of this molecular mechanism and the specificity of the network is reviewed and discussed in detail.
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32
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Fosser NS, Ronco L, Bejarano A, Paganelli AR, Ríos H. Calbindin-D28k and calretinin in chicken inner retina during postnatal development and neuroplasticity by dim red light. Dev Neurobiol 2013; 73:530-42. [PMID: 23447106 DOI: 10.1002/dneu.22081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 02/22/2013] [Accepted: 02/25/2013] [Indexed: 01/01/2023]
Abstract
Members of the family of calcium binding proteins (CBPs) are involved in the buffering of calcium (Ca2+) by regulating how Ca2+ can operate within synapses or more globally in the entire cytoplasm and they are present in a particular arrangement in all types of retinal neurons. Calbindin D28k and calretinin belong to the family of CBPs and they are mainly co-expressed with other CBPs. Calbindin D28k is expressed in doubles cones, bipolar cells and in a subpopulation of amacrine and ganglion neurons. Calretinin is present in horizontal cells as well as in a subpopulation of amacrine and ganglion neurons. Both proteins fill the soma at the inner nuclear layer and the neuronal projections at the inner plexiform layer. Moreover, calbindin D28k and calretinin have been associated with neuronal plasticity in the central nervous system. During pre and early postnatal visual development, the visual system shows high responsiveness to environmental influences. In this work we observed modifications in the pattern of stratification of calbindin immunoreactive neurons, as well as in the total amount of calbindin through the early postnatal development. In order to test whether or not calbindin is involved in retinal plasticity we analyzed phosphorylated p38 MAPK expression, which showed a decrease in p-p38 MAPK, concomitant to the observed decrease of calbindin D28k. Results showed in this study suggest that calbindin is a molecule related with neuroplasticity, and we suggest that calbindin D28k has significant roles in neuroplastic changes in the retina, when retinas are stimulated with different light conditions.
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Affiliation(s)
- Nicolás Sebastián Fosser
- Instituto de Biología Celular y Neurociencias Prof. E. De Robertis, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 2do. piso, Ciudad Autónoma de Buenos Aires, C1121ABG, Argentina
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33
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Zhou J, Sun J, Huang Y, Zhou C, Liang P, Zheng M, Liang C, Xu J, Li X, Yu X. Molecular identification, immunolocalization, and characterization of Clonorchis sinensis calmodulin. Parasitol Res 2013; 112:1709-17. [PMID: 23417096 DOI: 10.1007/s00436-013-3329-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 01/29/2013] [Indexed: 01/25/2023]
Abstract
One cDNA clone (Cs18h09) encoding Clonorchis sinensis calmodulin (CsCaM) was isolated from our adult cDNA plasmid library. The open reading frame of CsCaM contains 450 bp which encodes 149 amino acids. CsCaM protein comprises four calcium-binding EF-hand motifs. The amino acid sequence of CsCaM shares very high homology with other species. Quantitative RT-polymerase chain reaction (PCR) revealed that CsCaM mRNA was constitutively transcribed in development cycle stages of the parasite, including adult worm, metacercaria, excysted metacercaria, and egg. In addition, recombinant CsCaM (rCsCaM) was expressed as a soluble protein and anti-rCsCaM rat serum could detect CsCaM in the C. sinensis somatic extracts but not in the C. sinensis excretory-secretory products (ESPs). Moreover, immunolocalization assay showed that CsCaM was located in tegument, intestine, pharynx, and eggs. Furthermore, rCsCaM was found to bind calcium ion (Ca2+) and magnesium (Mg2+) in electrophoretic mobility shift assay. Ca2+ binding increased the ability of rCsCaM to bind the hydrophobic fluorescent probe 8-anilinonaphthalene-1-sulphonate, causing a blue shift in the fluorescence emission from 540 to 515 nm with an excitation wavelength of 380 nm and substantial increase in fluorescence intensity but not Mg2+. Collectively, here we showed the basic characterization of CsCaM and inferred that CsCaM could be a Ca2+ sensor protein, and CsCaM may possibly participate in growth and development of adult worm and egg of C. sinensis through binding Ca2+.
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Affiliation(s)
- Juanjuan Zhou
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, and Department of Clinical Laboratory, Sun Yat-sen Memorial Hospital, No 74, The Second Zhongshan RD, Guangzhou, Guangdong, 510080, China
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34
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Catterall WA, Leal K, Nanou E. Calcium channels and short-term synaptic plasticity. J Biol Chem 2013; 288:10742-9. [PMID: 23400776 DOI: 10.1074/jbc.r112.411645] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Voltage-gated Ca(2+) channels in presynaptic nerve terminals initiate neurotransmitter release in response to depolarization by action potentials from the nerve axon. The strength of synaptic transmission is dependent on the third to fourth power of Ca(2+) entry, placing the Ca(2+) channels in a unique position for regulation of synaptic strength. Short-term synaptic plasticity regulates the strength of neurotransmission through facilitation and depression on the millisecond time scale and plays a key role in encoding information in the nervous system. Ca(V)2.1 channels are the major source of Ca(2+) entry for neurotransmission in the central nervous system. They are tightly regulated by Ca(2+), calmodulin, and related Ca(2+) sensor proteins, which cause facilitation and inactivation of channel activity. Emerging evidence reviewed here points to this mode of regulation of Ca(V)2.1 channels as a major contributor to short-term synaptic plasticity of neurotransmission and its diversity among synapses.
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Affiliation(s)
- William A Catterall
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280, USA
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35
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Haeseleer F, Sokal I, Gregory FD, Lee A. Protein phosphatase 2A dephosphorylates CaBP4 and regulates CaBP4 function. Invest Ophthalmol Vis Sci 2013; 54:1214-26. [PMID: 23341017 DOI: 10.1167/iovs.12-11319] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE CaBP4 is a neuronal Ca(2+)-binding protein that is expressed in the retina and in the cochlea, and is essential for normal photoreceptor synaptic function. CaBP4 is phosphorylated by protein kinase C zeta (PKCζ) in the retina at serine 37, which affects its interaction with and modulation of voltage-gated Ca(v)1 Ca(2+) channels. In this study, we investigated the potential role and functional significance of protein phosphatase 2A (PP2A) in CaBP4 dephosphorylation. METHODS The effect of protein phosphatase inhibitors, light, and overexpression of PP2A subunits on CaBP4 dephosphorylation was measured in in vitro assays. Pull-down experiments using retinal or transfected HEK293 cell lysates were used to investigate the association between CaBP4 and PP2A subunits. Electrophysiologic recordings of cotransfected HEK293 cells were performed to analyze the effect of CaBP4 dephosphorylation in modulating Ca(v)1.3 currents. RESULTS PP2A inhibitors, okadaic acid (OA), and fostriecin, but not PP1 selective inhibitors, NIPP-1, and inhibitor 2, block CaBP4 dephosphorylation in retinal lysates. Increased phosphatase activity in light-dependent conditions reverses phosphorylation of CaBP4 by PKCζ. In HEK293 cells, overexpression of PP2A enhances the rate of dephosphorylation of CaBP4. In addition, inhibition of protein phosphatase activity by OA increases CaBP4 phosphorylation and potentiates the modulatory effect of CaBP4 on Ca(v)1.3 Ca(2+) channels in HEK293T cells. CONCLUSIONS This study provides evidence that CaBP4 is dephosphorylated by PP2A in the retina. Our findings reveal a novel role for protein phosphatases in regulating CaBP4 function in the retina, which may fine tune presynaptic Ca(2+) signals at the photoreceptor synapse.
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Affiliation(s)
- Françoise Haeseleer
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA.
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36
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Reyes-Bermudez A, Miller DJ, Sprungala S. The Neuronal Calcium Sensor protein Acrocalcin: a potential target of calmodulin regulation during development in the coral Acropora millepora. PLoS One 2012; 7:e51689. [PMID: 23284743 PMCID: PMC3524228 DOI: 10.1371/journal.pone.0051689] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/05/2012] [Indexed: 12/28/2022] Open
Abstract
To understand the calcium-mediated signalling pathways underlying settlement and metamorphosis in the Scleractinian coral Acropora millepora, a predicted protein set derived from larval cDNAs was scanned for the presence of EF-hand domains (Pfam Id: PF00036). This approach led to the identification of a canonical calmodulin (AmCaM) protein and an uncharacterised member of the Neuronal Calcium Sensor (NCS) family of proteins known here as Acrocalcin (AmAC). While AmCaM transcripts were present throughout development, AmAC transcripts were not detected prior to gastrulation, after which relatively constant mRNA levels were detected until metamorphosis and settlement. The AmAC protein contains an internal CaM-binding site and was shown to interact in vitro with AmCaM. These results are consistent with the idea that AmAC is a target of AmCaM in vivo, suggesting that this interaction may regulate calcium-dependent processes during the development of Acropora millepora.
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Affiliation(s)
- Alejandro Reyes-Bermudez
- ARC Centre of Excellence for Coral Reef Studies and School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Queensland, Australia
- Okinawa Institute of Science and Technology, Okinawa, Japan
| | - David J. Miller
- ARC Centre of Excellence for Coral Reef Studies and School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Queensland, Australia
| | - Susanne Sprungala
- ARC Centre of Excellence for Coral Reef Studies and School of Pharmacy and Molecular Sciences, James Cook University, Townsville, Queensland, Australia
- * E-mail:
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37
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Schrauwen I, Helfmann S, Inagaki A, Predoehl F, Tabatabaiefar MA, Picher MM, Sommen M, Zazo Seco C, Oostrik J, Kremer H, Dheedene A, Claes C, Fransen E, Chaleshtori MH, Coucke P, Lee A, Moser T, Van Camp G. A mutation in CABP2, expressed in cochlear hair cells, causes autosomal-recessive hearing impairment. Am J Hum Genet 2012; 91:636-45. [PMID: 22981119 DOI: 10.1016/j.ajhg.2012.08.018] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 07/10/2012] [Accepted: 08/15/2012] [Indexed: 11/17/2022] Open
Abstract
CaBPs are a family of Ca(2+)-binding proteins related to calmodulin and are localized in the brain and sensory organs, including the retina and cochlea. Although their physiological roles are not yet fully elucidated, CaBPs modulate Ca(2+) signaling through effectors such as voltage-gated Ca(v) Ca(2+) channels. In this study, we identified a splice-site mutation (c.637+1G>T) in Ca(2+)-binding protein 2 (CABP2) in three consanguineous Iranian families affected by moderate-to-severe hearing loss. This mutation, most likely a founder mutation, probably leads to skipping of exon 6 and premature truncation of the protein (p.Phe164Serfs(∗)4). Compared with wild-type CaBP2, the truncated CaBP2 showed altered Ca(2+) binding in isothermal titration calorimetry and less potent regulation of Ca(v)1.3 Ca(2+) channels. We show that genetic defects in CABP2 cause moderate-to-severe sensorineural hearing impairment. The mutation might cause a hypofunctional CaBP2 defective in Ca(2+) sensing and effector regulation in the inner ear.
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Affiliation(s)
- Isabelle Schrauwen
- Department of Medical Genetics, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
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38
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Fine-tuning synaptic plasticity by modulation of Ca(V)2.1 channels with Ca2+ sensor proteins. Proc Natl Acad Sci U S A 2012; 109:17069-74. [PMID: 23027954 DOI: 10.1073/pnas.1215172109] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Modulation of P/Q-type Ca(2+) currents through presynaptic voltage-gated calcium channels (Ca(V)2.1) by binding of Ca(2+)/calmodulin contributes to short-term synaptic plasticity. Ca(2+)-binding protein-1 (CaBP1) and Visinin-like protein-2 (VILIP-2) are neurospecific calmodulin-like Ca(2+) sensor proteins that differentially modulate Ca(V)2.1 channels, but how they contribute to short-term synaptic plasticity is unknown. Here, we show that activity-dependent modulation of presynaptic Ca(V)2.1 channels by CaBP1 and VILIP-2 has opposing effects on short-term synaptic plasticity in superior cervical ganglion neurons. Expression of CaBP1, which blocks Ca(2+)-dependent facilitation of P/Q-type Ca(2+) current, markedly reduced facilitation of synaptic transmission. VILIP-2, which blocks Ca(2+)-dependent inactivation of P/Q-type Ca(2+) current, reduced synaptic depression and increased facilitation under conditions of high release probability. These results demonstrate that activity-dependent regulation of presynaptic Ca(V)2.1 channels by differentially expressed Ca(2+) sensor proteins can fine-tune synaptic responses to trains of action potentials and thereby contribute to the diversity of short-term synaptic plasticity.
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Shaltiel L, Paparizos C, Fenske S, Hassan S, Gruner C, Rötzer K, Biel M, Wahl-Schott CA. Complex regulation of voltage-dependent activation and inactivation properties of retinal voltage-gated Cav1.4 L-type Ca2+ channels by Ca2+-binding protein 4 (CaBP4). J Biol Chem 2012; 287:36312-21. [PMID: 22936811 DOI: 10.1074/jbc.m112.392811] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cav1.4 L-type Ca(2+) channels are crucial for synaptic transmission in retinal photoreceptors and bipolar neurons. Recent studies suggest that the activity of this channel is regulated by the Ca(2+)-binding protein 4 (CaBP4). In the present study, we explored this issue by examining functional effects of CaBP4 on heterologously expressed Cav1.4. We show that CaBP4 dramatically increases Cav1.4 channel availability. This effect crucially depends on the presence of the C-terminal ICDI (inhibitor of Ca(2+)-dependent inactivation) domain of Cav1.4 and is absent in a Cav1.4 mutant lacking the ICDI. Using FRET experiments, we demonstrate that CaBP4 interacts with the IQ motif of Cav1.4 and that it interferes with the binding of the ICDI domain. Based on these findings, we suggest that CaBP4 increases Cav1.4 channel availability by relieving the inhibitory effects of the ICDI domain on voltage-dependent Cav1.4 channel gating. We also functionally characterized two CaBP4 mutants that are associated with a congenital variant of human night blindness and other closely related nonstationary retinal diseases. Although both mutants interact with Cav1.4 channels, the functional effects of CaBP4 mutants are only partially preserved, leading to a reduction of Cav1.4 channel availability and loss of function. In conclusion, our study sheds new light on the functional interaction between CaBP4 and Cav1.4. Moreover, it provides insights into the mechanism by which CaBP4 mutants lead to loss of Cav1.4 function and to retinal disease.
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Affiliation(s)
- Lior Shaltiel
- Center for Integrated Protein Science CIPS-M, Department Pharmazie, Ludwig-Maximilians-Universität München, D-81377 München, Germany
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Ames JB, Lim S. Molecular structure and target recognition of neuronal calcium sensor proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1820:1205-13. [PMID: 22020049 PMCID: PMC3266469 DOI: 10.1016/j.bbagen.2011.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/06/2011] [Accepted: 10/07/2011] [Indexed: 02/06/2023]
Abstract
BACKGROUND Neuronal calcium sensor (NCS) proteins, a sub-branch of the calmodulin superfamily, are expressed in the brain and retina where they transduce calcium signals and are genetically linked to degenerative diseases. The amino acid sequences of NCS proteins are highly conserved but their physiological functions are quite distinct. Retinal recoverin and guanylate cyclase activating proteins (GCAPs) both serve as calcium sensors in retinal rod cells, neuronal frequenin (NCS1) modulate synaptic activity and neuronal secretion, K+ channel interacting proteins (KChIPs) regulate ion channels to control neuronal excitability, and DREAM (KChIP3) is a transcriptional repressor that regulates neuronal gene expression. SCOPE OF REVIEW Here we review the molecular structures of myristoylated forms of NCS1, recoverin, and GCAP1 that all look very different, suggesting that the sequestered myristoyl group helps to refold these highly homologous proteins into very different structures. The molecular structure of NCS target complexes have been solved for recoverin bound to rhodopsin kinase, NCS-1 bound to phosphatidylinositol 4-kinase, and KChIP1 bound to A-type K+ channels. MAJOR CONCLUSIONS We propose the idea that N-terminal myristoylation is critical for shaping each NCS family member into a unique structure, which upon Ca2+-induced extrusion of the myristoyl group exposes a unique set of previously masked residues, thereby exposing a distinctive ensemble of hydrophobic residues to associate specifically with a particular physiological target. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signaling.
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Affiliation(s)
- James B Ames
- University of California, Davis Department of Chemistry, Davis, CA 95616, USa.
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41
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Pettelkau J, Schröder T, Ihling CH, Olausson BES, Kölbel K, Lange C, Sinz A. Structural Insights into Retinal Guanylylcyclase–GCAP-2 Interaction Determined by Cross-Linking and Mass Spectrometry. Biochemistry 2012; 51:4932-49. [DOI: 10.1021/bi300064v] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jens Pettelkau
- Department
of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Straße
4, D-06120 Halle (Saale), Germany
| | - Thomas Schröder
- Department of Technical Biochemistry, Institute of Biochemistry and
Biotechnology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, D-06120 Halle (Saale), Germany
| | - Christian H. Ihling
- Department
of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Straße
4, D-06120 Halle (Saale), Germany
| | - Björn E. S. Olausson
- Department
of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Straße
4, D-06120 Halle (Saale), Germany
| | - Knut Kölbel
- Department
of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Straße
4, D-06120 Halle (Saale), Germany
| | - Christian Lange
- Department of Technical Biochemistry, Institute of Biochemistry and
Biotechnology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Straße 3, D-06120 Halle (Saale), Germany
| | - Andrea Sinz
- Department
of Pharmaceutical Chemistry and Bioanalytics, Institute of Pharmacy, Martin-Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Straße
4, D-06120 Halle (Saale), Germany
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42
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Pan Z, Zhao Y, Zheng Y, Liu J, Jiang X, Guo Y. A high-throughput method for screening Arabidopsis mutants with disordered abiotic stress-induced calcium signal. J Genet Genomics 2012; 39:225-35. [PMID: 22624884 DOI: 10.1016/j.jgg.2012.04.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/01/2012] [Accepted: 04/01/2012] [Indexed: 11/25/2022]
Abstract
It is established that different stresses cause signal-specific changes in cellular Ca(2+) level, which function as messengers in modulating diverse physiological processes. These calcium signals are important for stress adaptation. Though numbers of downstream components of calcium signal cascades have been identified, upstream events in calcium signal remain elusive, specifically components required for calcium signal generation due to the lack of high-throughput genetic assay. Here, we report the development of an easy and efficient method in a forward genetic screen for Ca(2+) signals-deficient mutants in Arabidopsis thaliana. Using this method, 121 mutants with disordered NaCl- and H(2)O(2)-induced Ca(2+) signals are isolated.
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Affiliation(s)
- Zhen Pan
- College of Life Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
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43
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Schmitz F, Natarajan S, Venkatesan JK, Wahl S, Schwarz K, Grabner CP. EF hand-mediated Ca- and cGMP-signaling in photoreceptor synaptic terminals. Front Mol Neurosci 2012; 5:26. [PMID: 22393316 PMCID: PMC3289946 DOI: 10.3389/fnmol.2012.00026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 02/15/2012] [Indexed: 12/11/2022] Open
Abstract
Photoreceptors, the light-sensitive receptor neurons of the retina, receive and transmit a plethora of visual informations from the surrounding world. Photoreceptors capture light and convert this energy into electrical signals that are conveyed to the inner retina. For synaptic communication with the inner retina, photoreceptors make large active zones that are marked by synaptic ribbons. These unique synapses support continuous vesicle exocytosis that is modulated by light-induced, graded changes of membrane potential. Synaptic transmission can be adjusted in an activity-dependent manner, and at the synaptic ribbons, Ca2+- and cGMP-dependent processes appear to play a central role. EF-hand-containing proteins mediate many of these Ca2+- and cGMP-dependent functions. Since continuous signaling of photoreceptors appears to be prone to malfunction, disturbances of Ca2+- and cGMP-mediated signaling in photoreceptors can lead to visual defects, retinal degeneration (rd), and even blindness. This review summarizes aspects of signal transmission at the photoreceptor presynaptic terminals that involve EF-hand-containing Ca2+-binding proteins.
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Affiliation(s)
- Frank Schmitz
- Department of Neuroanatomy, Medical School Homburg/Saar, Institute for Anatomy and Cell Biology, Saarland University Saarland, Germany
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44
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Ames JB, Lim S, Ikura M. Molecular structure and target recognition of neuronal calcium sensor proteins. Front Mol Neurosci 2012; 5:10. [PMID: 22363261 PMCID: PMC3275791 DOI: 10.3389/fnmol.2012.00010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 01/26/2012] [Indexed: 01/19/2023] Open
Abstract
Neuronal calcium sensor (NCS) proteins, a sub-branch of the EF-hand superfamily, are expressed in the brain and retina where they transduce calcium signals and are genetically linked to degenerative diseases. The amino acid sequences of NCS proteins are highly conserved but their physiological functions are quite distinct. Retinal recoverin and guanylate cyclase activating proteins (GCAPs) both serve as calcium sensors in retinal rod cells, neuronal frequenin (NCS1) modulates synaptic activity and neuronal secretion, K+ channel interacting proteins (KChIPs) regulate ion channels to control neuronal excitability, and DREAM (KChIP3) is a transcriptional repressor that regulates neuronal gene expression. Here we review the molecular structures of myristoylated forms of NCS1, recoverin, and GCAP1 that all look very different, suggesting that the sequestered myristoyl group helps to refold these highly homologous proteins into very different structures. The molecular structure of NCS target complexes have been solved for recoverin bound to rhodopsin kinase (RK), NCS-1 bound to phosphatidylinositol 4-kinase, and KChIP1 bound to A-type K+ channels. We propose that N-terminal myristoylation is critical for shaping each NCS family member into a different structure, which upon Ca2+-induced extrusion of the myristoyl group exposes a unique set of previously masked residues that interact with a particular physiological target.
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Affiliation(s)
- James B Ames
- Department of Chemistry, University of California, Davis CA, USA
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45
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Christel C, Lee A. Ca2+-dependent modulation of voltage-gated Ca2+ channels. Biochim Biophys Acta Gen Subj 2011; 1820:1243-52. [PMID: 22223119 DOI: 10.1016/j.bbagen.2011.12.012] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2011] [Revised: 12/15/2011] [Accepted: 12/16/2011] [Indexed: 01/06/2023]
Abstract
BACKGROUND Voltage-gated (Cav) Ca2+ channels are multi-subunit complexes that play diverse roles in a wide variety of tissues. A fundamental mechanism controlling Cav channel function involves the Ca2+ ions that permeate the channel pore. Ca2+ influx through Cav channels mediates feedback regulation to the channel that is both negative (Ca2+-dependent inactivation, CDI) and positive (Ca2+-dependent facilitation, CDF). SCOPE OF REVIEW This review highlights general mechanisms of CDI and CDF with an emphasis on how these processes have been studied electrophysiologically in native and heterologous expression systems. MAJOR CONCLUSIONS Electrophysiological analyses have led to detailed insights into the mechanisms and prevalence of CDI and CDF as Cav channel regulatory mechanisms. All Cav channel family members undergo some form of Ca2+-dependent feedback that relies on CaM or a related Ca2+ binding protein. Tremendous progress has been made in characterizing the role of CaM in CDI and CDF. Yet, what contributes to the heterogeneity of CDI/CDF in various cell-types and how Ca2+-dependent regulation of Cav channels controls Ca2+ signaling remain largely unexplored. GENERAL SIGNIFICANCE Ca2+ influx through Cav channels regulates diverse physiological events including excitation-contraction coupling in muscle, neurotransmitter and hormone release, and Ca2+-dependent gene transcription. Therefore, the mechanisms that regulate channels, such as CDI and CDF, can have a large impact on the signaling potential of excitable cells in various physiological contexts. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signaling.
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Affiliation(s)
- Carl Christel
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USA
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Sokal I, Haeseleer F. Insight into the role of Ca2+-binding protein 5 in vesicle exocytosis. Invest Ophthalmol Vis Sci 2011; 52:9131-41. [PMID: 22039235 DOI: 10.1167/iovs.11-8246] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE CaBP5 is a neuronal calmodulin-like Ca(2+)-binding protein that is expressed in the retina and in the cochlea. Although CaBP5 knockout mice displayed reduced sensitivity of retinal ganglion cell light responses, the function of CaBP5 in vivo is still unknown. To gain further insight into CaBP5 function, the authors screened for CaBP5-interacting partners. METHODS Potential retinal interacting partners for CaBP5 were identified using affinity chromatography followed by mass spectrometry and by yeast two-hybrid screening of a bovine retina cDNA library. Interacting partners were further analyzed using coimmunoprecipitation. Immunohistochemistry and subcellular fractionation were performed to determine their colocalization in the retina. The effect of CaBP5 on dopamine release and neurite outgrowth of PC12 cells was analyzed using ELISA and fluorescent labeling. RESULTS Using affinity chromatography, the authors identified Munc18-1 and myosin VI as interacting partners for CaBP5. Munc18-1 was also identified using the yeast two-hybrid system. Colocalization and coimmunoprecipitation of CaBP5 with these two proteins in retinal tissue further established their physiological interactions. Furthermore, CaBP5 expression in NGF-stimulated PC12 cells stimulates neurite outgrowth and dopamine exocytosis. CONCLUSIONS This study shows that CaBP5 interacts with Munc18-1 and myosin VI, two proteins involved in the synaptic vesicle cycle. Together with the effect of CaBP5 in stimulating neurite outgrowth and vesicle exocytosis in PC12 cells, these results suggest that CaBP5 plays a role in neurotransmitter release.
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Affiliation(s)
- Izabela Sokal
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA
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McMurry JL, Chrestensen CA, Scott IM, Lee EW, Rahn AM, Johansen AM, Forsberg BJ, Harris KD, Salerno JC. Rate, affinity and calcium dependence of nitric oxide synthase isoform binding to the primary physiological regulator calmodulin. FEBS J 2011; 278:4943-54. [PMID: 22004458 DOI: 10.1111/j.1742-4658.2011.08395.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using interferometry-based biosensors the binding and release of endothelial and neuronal nitric oxide synthase (eNOS and nNOS) from calmodulin (CaM) was measured. In both isoforms, binding to CaM is diffusion limited and within approximately three orders of magnitude of the Smoluchowski limit imposed by orientation-independent collisions. This suggests that the orientation of CaM is facilitated by the charge arrays on the CaM-binding site and the complementary surface on CaM. Protein kinase C phosphorylation of eNOS T495, adjacent to the CaM-binding site, abolishes or greatly slows CaM binding. Kinases which increase the activity of eNOS did not stimulate the binding of CaM, which is already diffusion limited. The coupling of Ca(2+) binding and CaM/NOS binding equilibria links the affinity of CaM for NOS to the Ca(2+) dependence of CaM binding. Hence, changes in the Ca(2+) sensitivity of CaM binding always imply changes in the NOS-CaM affinity. It is possible, however, that in some regimes binding and activation are not synonymous, so that Ca(2+) sensitivity need not be tightly linked to CaM sensitivity of activation. This study is being extended using mutants to probe the roles of individual structural elements in binding and release.
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Affiliation(s)
- Jonathan L McMurry
- Department of Chemistry & Biochemistry, Kennesaw State University, Kennesaw, GA 30144, USA
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Nanou E, Martinez GQ, Scheuer T, Catterall WA. Molecular determinants of modulation of CaV2.1 channels by visinin-like protein 2. J Biol Chem 2011; 287:504-513. [PMID: 22074920 DOI: 10.1074/jbc.m111.292581] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CaV2.1 channels, which conduct P/Q-type Ca2+ currents, initiate synaptic transmission at most synapses in the central nervous system. Ca2+/calmodulin-dependent facilitation and inactivation of these channels contributes to short-term facilitation and depression of synaptic transmission, respectively. Other calcium sensor proteins displace calmodulin (CaM) from its binding site, differentially regulate CaV2.1 channels, and contribute to the diversity of short-term synaptic plasticity. The neuronal calcium sensor protein visinin-like protein 2 (VILIP-2) inhibits inactivation and enhances facilitation of CaV2.1 channels. Here we examine the molecular determinants for differential regulation of CaV2.1 channels by VILIP-2 and CaM by construction and functional analysis of chimeras in which the functional domains of VILIP-2 are substituted in CaM. Our results show that the N-terminal domain, including its myristoylation site, the central α-helix, and the C-terminal lobe containing EF-hands 3 and 4 of VILIP-2 are sufficient to transfer its regulatory properties to CaM. This regulation by VILIP-2 requires binding to the IQ-like domain of CaV2.1 channels. Our results identify the essential molecular determinants of differential regulation of CaV2.1 channels by VILIP-2 and define the molecular code that these proteins use to control short-term synaptic plasticity.
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Affiliation(s)
- Evanthia Nanou
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280
| | - Gilbert Q Martinez
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280
| | - Todd Scheuer
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280.
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Mikhaylova M, Hradsky J, Kreutz MR. Between promiscuity and specificity: novel roles of EF-hand calcium sensors in neuronal Ca2+ signalling. J Neurochem 2011; 118:695-713. [PMID: 21722133 DOI: 10.1111/j.1471-4159.2011.07372.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In recent years, substantial progress has been made towards an understanding of the physiological function of EF-hand calcium sensor proteins of the Calmodulin (CaM) superfamily in neurons. This deeper appreciation is based on the identification of novel target interactions, structural studies and the discovery of novel signalling mechanisms in protein trafficking and synaptic plasticity, in which CaM-like sensor proteins appear to play a role. However, not all interactions are of plausible physiological relevance and in many cases it is not yet clear how the CaM signaling network relates to the proposed function of other EF-hand sensors. In this review, we will summarize these findings and address some of the open questions on the functional role of EF-hand calcium binding proteins in neurons.
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Affiliation(s)
- Marina Mikhaylova
- PG Neuroplasticity, Leibniz-Institute for Neurobiology, Magdeburg, Germany
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50
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Sensing change: The emerging role of calcium sensors in neuronal disease. Semin Cell Dev Biol 2011; 22:530-5. [DOI: 10.1016/j.semcdb.2011.07.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 07/18/2011] [Indexed: 11/20/2022]
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