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Zeitz C, Roger JE, Audo I, Michiels C, Sánchez-Farías N, Varin J, Frederiksen H, Wilmet B, Callebert J, Gimenez ML, Bouzidi N, Blond F, Guilllonneau X, Fouquet S, Léveillard T, Smirnov V, Vincent A, Héon E, Sahel JA, Kloeckener-Gruissem B, Sennlaub F, Morgans CW, Duvoisin RM, Tkatchenko AV, Picaud S. Shedding light on myopia by studying complete congenital stationary night blindness. Prog Retin Eye Res 2023; 93:101155. [PMID: 36669906 DOI: 10.1016/j.preteyeres.2022.101155] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 01/20/2023]
Abstract
Myopia is the most common eye disorder, caused by heterogeneous genetic and environmental factors. Rare progressive and stationary inherited retinal disorders are often associated with high myopia. Genes implicated in myopia encode proteins involved in a variety of biological processes including eye morphogenesis, extracellular matrix organization, visual perception, circadian rhythms, and retinal signaling. Differentially expressed genes (DEGs) identified in animal models mimicking myopia are helpful in suggesting candidate genes implicated in human myopia. Complete congenital stationary night blindness (cCSNB) in humans and animal models represents an ON-bipolar cell signal transmission defect and is also associated with high myopia. Thus, it represents also an interesting model to identify myopia-related genes, as well as disease mechanisms. While the origin of night blindness is molecularly well established, further research is needed to elucidate the mechanisms of myopia development in subjects with cCSNB. Using whole transcriptome analysis on three different mouse models of cCSNB (in Gpr179-/-, Lrit3-/- and Grm6-/-), we identified novel actors of the retinal signaling cascade, which are also novel candidate genes for myopia. Meta-analysis of our transcriptomic data with published transcriptomic databases and genome-wide association studies from myopia cases led us to propose new biological/cellular processes/mechanisms potentially at the origin of myopia in cCSNB subjects. The results provide a foundation to guide the development of pharmacological myopia therapies.
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Affiliation(s)
- Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.
| | - Jérome E Roger
- Paris-Saclay Institute of Neuroscience, CERTO-Retina France, CNRS, Université Paris-Saclay, Saclay, France
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, Paris, France
| | | | | | - Juliette Varin
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Helen Frederiksen
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Baptiste Wilmet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Jacques Callebert
- Service of Biochemistry and Molecular Biology, INSERM U942, Hospital Lariboisière, APHP, Paris, France
| | | | - Nassima Bouzidi
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Frederic Blond
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | | | - Stéphane Fouquet
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | | | - Vasily Smirnov
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, ON, Canada; Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, ON, Canada; Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France; CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, Paris, France; Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | - Florian Sennlaub
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Catherine W Morgans
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR, USA
| | - Robert M Duvoisin
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR, USA
| | - Andrei V Tkatchenko
- Oujiang Laboratory, Zhejiang Laboratory for Regenerative Medicine, Vision and Brain Health, Wenzhou, China; Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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Chen L, Al-Harthi L, Hu XT. Triumeq Increases Excitability of Pyramidal Neurons in the Medial Prefrontal Cortex by Facilitating Voltage-Gated Ca 2+ Channel Function. Front Pharmacol 2021; 11:617149. [PMID: 33584297 PMCID: PMC7876243 DOI: 10.3389/fphar.2020.617149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/30/2020] [Indexed: 12/24/2022] Open
Abstract
Combination antiretroviral therapy (cART) suppresses HIV-1 replication, improves immune function, and prolongs the life of people living with HIV (PLWH). However, cART also induces neurotoxicity that could complicate HIV-induced neurodegeneration while reduce its therapeutic efficacy in treating HIV/AIDS. Triumeq is a first-line cART regimen, which is co-formulated by three antiretroviral drugs (ARVs), lamivudine (3TC), abcavir (ABC), and dolutegravir (DTG). Little is known about potential side effects of ARVs on the brain (including those co-formulating Triumeq), and their mechanisms impacting neuronal activity. We assessed acute (in vitro) and chronic (in vivo) effects of Triumeq and co-formulating ARVs on pyramidal neurons in rat brain slices containing the medial prefrontal cortex (mPFC) using patch-clamp recording approaches. We found that acute Triumeq or 3TC in vitro significantly increased firing of mPFC neurons in a concentration- and time-dependent manner. This neuronal hyperactivity was associated with enhanced Ca2+ influx through voltage-gated Ca2+ channels (VGCCs). Additionally, chronic treatment with Triumeq in vivo for 4 weeks (4 wks) also significantly increased firing and Ca2+ influx via VGCCs in mPFC neurons, which was not shown after 2 wks treatment. Such mPFC neuronal hyperexcitability was not found after 4 weeks treatments of individual ARVs. Further, chronic Triumeq exposure in vivo significantly enhanced mRNA expression of low voltage-activated (LVA) L-type Ca2+ channels (Cav1.3 L-channels), while changes in high voltage-activated (HVA) Cav1.2 L-channels were not observed. Collectively, these novel findings demonstrate that chronic cART induces hyperexcitability of mPFC pyramidal neurons by abnormally promoting VGCC overactivation/overexpression of VGCCs (including, but may not limited to, LVA-Cav1.3 L-channels), which could complicate HIV-induced neurotoxicity, and ultimately may contribute to HIV-associated neurocognitive disorders (HAND) in PLWH. Determining additional target(s) of cART in mPFC pyramidal neurons may help to improve the therapeutic strategies by minimizing the side effects of cART for treating HIV/AIDS.
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Affiliation(s)
| | | | - Xiu-Ti Hu
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL, United States
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Senatore A, Raiss H, Le P. Physiology and Evolution of Voltage-Gated Calcium Channels in Early Diverging Animal Phyla: Cnidaria, Placozoa, Porifera and Ctenophora. Front Physiol 2016; 7:481. [PMID: 27867359 PMCID: PMC5095125 DOI: 10.3389/fphys.2016.00481] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/07/2016] [Indexed: 12/18/2022] Open
Abstract
Voltage-gated calcium (Cav) channels serve dual roles in the cell, where they can both depolarize the membrane potential for electrical excitability, and activate transient cytoplasmic Ca2+ signals. In animals, Cav channels play crucial roles including driving muscle contraction (excitation-contraction coupling), gene expression (excitation-transcription coupling), pre-synaptic and neuroendocrine exocytosis (excitation-secretion coupling), regulation of flagellar/ciliary beating, and regulation of cellular excitability, either directly or through modulation of other Ca2+-sensitive ion channels. In recent years, genome sequencing has provided significant insights into the molecular evolution of Cav channels. Furthermore, expanded gene datasets have permitted improved inference of the species phylogeny at the base of Metazoa, providing clearer insights into the evolution of complex animal traits which involve Cav channels, including the nervous system. For the various types of metazoan Cav channels, key properties that determine their cellular contribution include: Ion selectivity, pore gating, and, importantly, cytoplasmic protein-protein interactions that direct sub-cellular localization and functional complexing. It is unclear when these defining features, many of which are essential for nervous system function, evolved. In this review, we highlight some experimental observations that implicate Cav channels in the physiology and behavior of the most early-diverging animals from the phyla Cnidaria, Placozoa, Porifera, and Ctenophora. Given our limited understanding of the molecular biology of Cav channels in these basal animal lineages, we infer insights from better-studied vertebrate and invertebrate animals. We also highlight some apparently conserved cellular functions of Cav channels, which might have emerged very early on during metazoan evolution, or perhaps predated it.
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Affiliation(s)
- Adriano Senatore
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
| | - Hamad Raiss
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
| | - Phuong Le
- Department of Biology, University of Toronto Mississauga Mississauga, ON, Canada
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Khodr CE, Chen L, Dave S, Al-Harthi L, Hu XT. Combined chronic blockade of hyper-active L-type calcium channels and NMDA receptors ameliorates HIV-1 associated hyper-excitability of mPFC pyramidal neurons. Neurobiol Dis 2016; 94:85-94. [PMID: 27326669 PMCID: PMC4983475 DOI: 10.1016/j.nbd.2016.06.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/04/2016] [Accepted: 06/16/2016] [Indexed: 01/09/2023] Open
Abstract
Human Immunodeficiency Virus type 1 (HIV-1) infection induces neurological and neuropsychological deficits, which are associated with dysregulation of the medial prefrontal cortex (mPFC) and other vulnerable brain regions. We evaluated the impact of HIV infection in the mPFC and the therapeutic potential of targeting over-active voltage-gated L-type Ca(2+) channels (L-channel) and NMDA receptors (NMDAR), as modeled in HIV-1 transgenic (Tg) rats. Whole-cell patch-clamp recording was used to assess the membrane properties and voltage-sensitive Ca(2+) potentials (Ca(2+) influx) in mPFC pyramidal neurons. Neurons from HIV-1 Tg rats displayed reduced rheobase, spike amplitude and inwardly-rectifying K(+) influx, increased numbers of action potentials, and a trend of aberrant firing compared to those from non-Tg control rats. Neuronal hyper-excitation was associated with abnormally-enhanced Ca(2+) influx (independent of NMDAR), which was eliminated by acute L-channel blockade. Combined chronic blockade of over-active L-channels and NMDARs with open-channel blockers abolished HIV effects on spiking, aberrant firing and Ca(2+) potential half-amplitude duration, though not the reduced inward rectification. In contrast, individual chronic blockade of over-active L-channels or NMDARs did not alleviate HIV-induced mPFC hyper-excitability. These studies demonstrate that HIV alters mPFC neuronal activity by dysregulating membrane excitability and Ca(2+) influx through the L-channels. This renders these neurons more susceptible and vulnerable to excitatory stimuli, and could contribute to HIV-associated neuropathogenesis. Combined targeting of over-active L-channels/NMDARs alleviates HIV-induced dysfunction of mPFC pyramidal neurons, emphasizing a potential novel therapeutic strategy that may effectively decrease HIV-induced Ca(2+) dysregulation in the mPFC.
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Affiliation(s)
- Christina E Khodr
- Department of Pharmacology, Rush University Medical Center, Chicago, IL 60612, United States
| | - Lihua Chen
- Department of Pharmacology, Rush University Medical Center, Chicago, IL 60612, United States
| | - Sonya Dave
- Department of Pharmacology, Rush University Medical Center, Chicago, IL 60612, United States
| | - Lena Al-Harthi
- Department of Immunology and Microbiology, Rush University Medical Center, Chicago, IL 60612, United States
| | - Xiu-Ti Hu
- Department of Pharmacology, Rush University Medical Center, Chicago, IL 60612, United States.
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Calcium signaling in cerebral vasoregulation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:833-58. [PMID: 22453972 DOI: 10.1007/978-94-007-2888-2_37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The tight coupling of regional neurometabolic activity with synaptic activity and regional cerebral blood perfusion constitutes a single functional unit, described generally as a neurovascular unit. This is central to any discussion of haemodynamic response linked to any neuronal activation. In normal as well as in pathologic conditions, neurons, astrocytes and endothelial cells of the vasculature interact to generate the complex activity-induced cerebral haemodynamic responses, with astrocytes not only partaking in the signaling but actually controlling it in many cases. Neurons and astrocytes have highly integrated signaling mechanisms, yet they form two separate networks. Bidirectional neuron-astrocyte interactions are crucial for the function and survival of the central nervous system. The primary purpose of such regulation is the homeostasis of the brain's microenvironment. In the maintenance of such homeostasis, astrocytic calcium response is a crucial variable in determining neurovascular control. Future work will be directed towards resolving the nature and extent of astrocytic calcium-mediated mechanisms for gene transcription, in modelling neurovascular control, and in determining calcium sensitive imaging assays that can capture disease variables.
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Molina C, Rotter B, Horres R, Udupa SM, Besser B, Bellarmino L, Baum M, Matsumura H, Terauchi R, Kahl G, Winter P. SuperSAGE: the drought stress-responsive transcriptome of chickpea roots. BMC Genomics 2008; 9:553. [PMID: 19025623 PMCID: PMC2628679 DOI: 10.1186/1471-2164-9-553] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Accepted: 11/24/2008] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Drought is the major constraint to increase yield in chickpea (Cicer arietinum). Improving drought tolerance is therefore of outmost importance for breeding. However, the complexity of the trait allowed only marginal progress. A solution to the current stagnation is expected from innovative molecular tools such as transcriptome analyses providing insight into stress-related gene activity, which combined with molecular markers and expression (e)QTL mapping, may accelerate knowledge-based breeding. SuperSAGE, an improved version of the serial analysis of gene expression (SAGE) technique, generating genome-wide, high-quality transcription profiles from any eukaryote, has been employed in the present study. The method produces 26 bp long fragments (26 bp tags) from defined positions in cDNAs, providing sufficient sequence information to unambiguously characterize the mRNAs. Further, SuperSAGE tags may be immediately used to produce microarrays and probes for real-time-PCR, thereby overcoming the lack of genomic tools in non-model organisms. RESULTS We applied SuperSAGE to the analysis of gene expression in chickpea roots in response to drought. To this end, we sequenced 80,238 26 bp tags representing 17,493 unique transcripts (UniTags) from drought-stressed and non-stressed control roots. A total of 7,532 (43%) UniTags were more than 2.7-fold differentially expressed, and 880 (5.0%) were regulated more than 8-fold upon stress. Their large size enabled the unambiguous annotation of 3,858 (22%) UniTags to genes or proteins in public data bases and thus to stress-response processes. We designed a microarray carrying 3,000 of these 26 bp tags. The chip data confirmed 79% of the tag-based results, whereas RT-PCR confirmed the SuperSAGE data in all cases. CONCLUSION This study represents the most comprehensive analysis of the drought-response transcriptome of chickpea available to date. It demonstrates that--inter alias--signal transduction, transcription regulation, osmolyte accumulation, and ROS scavenging undergo strong transcriptional remodelling in chickpea roots already 6 h after drought stress. Certain transcript isoforms characterizing these processes are potential targets for breeding for drought tolerance. We demonstrate that these can be easily accessed by micro-arrays and RT-PCR assays readily produced downstream of SuperSAGE. Our study proves that SuperSAGE owns potential for molecular breeding also in non-model crops.
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Affiliation(s)
- Carlos Molina
- Biocenter, Frankfurt University, Max-von-Laue-Str, 9, 60439 Frankfurt am Main, Germany.
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Abdi A, Tahoori MB, Emamian ES. Fault Diagnosis Engineering of Digital Circuits Can Identify Vulnerable Molecules in Complex Cellular Pathways. Sci Signal 2008; 1:ra10. [DOI: 10.1126/scisignal.2000008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Layton MG, Robertson D, Everett AW, Mulders WHAM, Yates GK. Cellular localization of voltage-gated calcium channels and synaptic vesicle-associated proteins in the guinea pig cochlea. J Mol Neurosci 2005; 27:225-44. [PMID: 16186634 DOI: 10.1385/jmn:27:2:225] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 03/07/2005] [Indexed: 11/11/2022]
Abstract
The cellular localization of voltage-gated calcium channels (VGCCs) and synaptic vesicle-associated proteins, SV2, synapsin I, and vesicle-associated membrane protein (VAMP) (synaptobrevin), was investigated in the guinea pig cochlea using immunocytochemistry and confocal laser scanning microscopy. Reactivity, in guinea pig, of antibodies to the alpha1 subunits of L-type, alpha1C [Cav1.2] and alpha 1D [Cav1.3]; P/Q-type, alpha1A [Cav2.1]; and R-type, a1E [Cav2.3] high voltage-activated calcium channels, was determined by Western blotting and immunolabeling of cerebellum. In the cochlea the sensory inner hair cells of the organ of Corti displayed strong intracellular staining, predominantly localized to their basolateral poles, with an antibody directed against the alpha1C subunit. Some alpha1C labeling was also observed in the inner pillar cells, in cell bodies of afferent neurons in the spiral ganglion, and in the inferior region of the spiral ligament. The supporting pillar cells were strongly immunoreactive throughout for alpha1D, but no alpha1D labeling of the inner hair cells was seen. The alpha1A subunit showed a cytoplasmic distribution in all three rows of outer hair cells. alpha1E labeling localized to the outer hair cells, predominantly in the subcuticular plate region, and also to nerve fiber bundles beneath these hair cells. Strong immunoreactivity was consistently seen with antibodies directed against SV2 and synapsin I in neuronal structures surrounding the basolateral surfaces of both the inner and outer hair cells but was absent from the sensory cells themselves. VAMP labeling was found throughout the cytoplasm of the inner hair cells and in neuronal structures beneath the hair cells. These results reveal a differential distribution of VGCC-types in the sensory and nonsensory elements of the guinea pig cochlea, with the inner hair cells expressing alpha1C L-type channels and VAMP but not synapsin I or SV2.
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Affiliation(s)
- Maria G Layton
- The Auditory Laboratory, School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, Western Australia, 6009, Australia
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Ok SH, Jeong HJ, Bae JM, Shin JS, Luan S, Kim KN. Novel CIPK1-associated proteins in Arabidopsis contain an evolutionarily conserved C-terminal region that mediates nuclear localization. PLANT PHYSIOLOGY 2005; 139:138-50. [PMID: 16113215 PMCID: PMC1203364 DOI: 10.1104/pp.105.065649] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2005] [Revised: 06/12/2005] [Accepted: 06/29/2005] [Indexed: 05/04/2023]
Abstract
Environmental stimuli, including light, pathogens, hormones, and abiotic stresses, elicit changes in the cytosolic Ca(2+) signatures of plant cells. However, little is known about the molecular mechanisms by which plants sense and transmit the specific cytoplasmic Ca(2+) signal into the nucleus, where gene regulation occurs to respond appropriately to the stress. In this study, we have identified two novel Arabidopsis (Arabidopsis thaliana) proteins specifically associated with Calcineurin B-Like-Interacting Protein Kinase1 (CIPK1), a member of Ser/Thr protein kinases that interact with the calcineurin B-like Ca(2+)-binding proteins. These two proteins contain a very similar C-terminal region (180 amino acids in length, 81% similarity), which is required and sufficient for both interaction with CIPK1 and translocation to the nucleus. Interestingly, the conserved C-terminal region was also found in many proteins from various eukaryotic organisms, including humans. However, none of them have been characterized so far. Taken together, these findings suggest that the two proteins containing the evolutionarily conserved C-terminal region (ECT1 and ECT2) may play a critical role in relaying the cytosolic Ca(2+) signals to the nucleus, thereby regulating gene expression.
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Affiliation(s)
- Sung Han Ok
- Department of Molecular Biology, Sejong University, Seoul, Korea
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Mori MX, Erickson MG, Yue DT. Functional Stoichiometry and Local Enrichment of Calmodulin Interacting with Ca2+ Channels. Science 2004; 304:432-5. [PMID: 15087548 DOI: 10.1126/science.1093490] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Calmodulin (CaM) interactions with Ca2+ channels mediate both Ca2+ regulation of channels and local Ca2+ triggering of transcription factors implicated in neuronal memory. Crucial to these functions are the number of CaM molecules (CaMs) regulating each channel, and the number of CaMs privy to the local Ca2+ signal from each channel. To resolve these parameters, we fused L-type Ca2+ channels to single CaM molecules. These chimeric molecules revealed that a single CaM directs L-type channel regulation. Similar fusion molecules were used to estimate the local CaM concentration near Ca2+ channels. This estimate indicates marked enrichment of local CaM, as if a "school" of nearby CaMs were poised to enhance the transduction of local Ca2+ entry into diverse signaling pathways.
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Affiliation(s)
- Masayuki X Mori
- Ca2+ Signals Laboratory, Department of Biomedical Engineering , Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD 21205, USA
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Liang H, DeMaria CD, Erickson MG, Mori MX, Alseikhan BA, Yue DT. Unified mechanisms of Ca2+ regulation across the Ca2+ channel family. Neuron 2003; 39:951-60. [PMID: 12971895 DOI: 10.1016/s0896-6273(03)00560-9] [Citation(s) in RCA: 249] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
L-type (CaV1.2) and P/Q-type (CaV2.1) calcium channels possess lobe-specific CaM regulation, where Ca2+ binding to one or the other lobe of CaM triggers regulation, even with inverted polarity of modulation between channels. Other major members of the CaV1-2 channel family, R-type (CaV2.3) and N-type (CaV2.2), have appeared to lack such CaM regulation. We report here that R- and N-type channels undergo Ca(2+)-dependent inactivation, which is mediated by the CaM N-terminal lobe and present only with mild Ca2+ buffering (0.5 mM EGTA) characteristic of many neurons. These features, together with the CaM regulatory profiles of L- and P/Q-type channels, are consistent with a simplifying principle for CaM signal detection in CaV1-2 channels-independent of channel context, the N- and C-terminal lobes of CaM appear invariably specialized for decoding local versus global Ca2+ activity, respectively.
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MESH Headings
- Amino Acid Sequence
- Animals
- Calcium/metabolism
- Calcium Channels/chemistry
- Calcium Channels/genetics
- Calcium Channels/metabolism
- Calcium Channels, L-Type/chemistry
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Channels, N-Type/chemistry
- Calcium Channels, N-Type/genetics
- Calcium Channels, N-Type/metabolism
- Calcium Channels, P-Type/chemistry
- Calcium Channels, P-Type/genetics
- Calcium Channels, P-Type/metabolism
- Calcium Channels, Q-Type/chemistry
- Calcium Channels, Q-Type/genetics
- Calcium Channels, Q-Type/metabolism
- Calcium Channels, R-Type/chemistry
- Calcium Channels, R-Type/genetics
- Calcium Channels, R-Type/metabolism
- Calmodulin/metabolism
- Cattle
- Cell Line
- Dose-Response Relationship, Drug
- Humans
- Molecular Sequence Data
- Rats
- Sequence Homology, Amino Acid
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Affiliation(s)
- Haoya Liang
- Ca2+ Signals Laboratory, Departments of Biomedical Engineering and Neuroscience, The Johns Hopkins University School of Medicine, 720 Rutland Avenue, Baltimore, MD 21205, USA
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Kelicen P, Cantuti-Castelvetri I, Pekiner C, Paulson KE. The spin trapping agent PBN stimulates H2 O2 -induced Erk and Src kinase activity in human neuroblastoma cells. Neuroreport 2002; 13:1057-61. [PMID: 12060808 DOI: 10.1097/00001756-200206120-00016] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The spin-trap, alpha-phenyl-N-tert-butylnitrone (PBN) has been shown to have neuroprotective properties and may prevent oxidative injury in vivo and in cultured cells. Although PBN quenches reactive oxygen species, the direct mechanism of neuroprotective action is unknown. In the present study, we examined the effects of PBN on the regulation of the mitogen activated kinase Erk and as well as Src family tyrosine kinases, enzymes known to be activated by oxygen species such as H2O2. In SH-SY5Y human neuroblastoma cells, H2O2 induced activation of Erk and Src kinases was markedly potentiated by treatment with PBN. The potentiation by PBN of the Erk and Src kinase activation by H2O2 required extracellular Ca2+ and appeared dependent on voltage sensitive Ca2+ channels. In contrast, PBN did not affect depolarization-dependent or growth factor-dependent Erk and Src kinase phosphorylation. Our results suggest that PBN might have a protective effect on cells by potentiating the anti-apoptotic Erk and Src kinase pathways responding to H2O2, an effect apparently distinct from its ability to trap oxygen free radicals.
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Affiliation(s)
- Pelin Kelicen
- Karolinska Institutet, Division of Molecular Toxicology, Institute of Environmental Medicine, S-171 77 Stockholm, Sweden
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Mermelstein PG, Deisseroth K, Dasgupta N, Isaksen AL, Tsien RW. Calmodulin priming: nuclear translocation of a calmodulin complex and the memory of prior neuronal activity. Proc Natl Acad Sci U S A 2001; 98:15342-7. [PMID: 11742070 PMCID: PMC65031 DOI: 10.1073/pnas.211563998] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The neuronal nucleus plays a vital role in information processing, but whether it supports computational functions such as paired-pulse facilitation, comparable to synapses, is unclear. Ca(2+)-dependent movement of calmodulin (CaM) to the nucleus is highly responsive to Ca(2+) entry through L-type channels and promotes activation of the transcription factor CREB (cAMP-responsive element binding protein) through phosphorylation by CaM-sensitive kinases. We characterized key features of this CaM translocation and its possible role in facilitation of nuclear signaling. Nuclear CaM was elevated within 15 s of stimulus onset, preceding the first signs of CREB phosphorylation in hippocampal pyramidal neurons. Depolarization-induced elevation of nuclear CaM also was observed in cerebellar granule cells, neocortical neurons, and dentate gyrus granule cells. Nuclear translocation of CaM was not blocked by disruption of actin filaments or microtubules, or by emptying endoplasmic reticulum Ca(2+) stores with thapsigargin. Translocation of fluorescently tagged CaM was prevented by fusing it with the Ca(2+)/CaM binding peptide M13, suggesting that nuclear CaM accumulation depends on association with endogenous Ca(2+)/CaM binding proteins. To determine whether increased nuclear [CaM] might influence subsequent nuclear signal processing, we compared responses to two consecutive depolarizing stimuli. After a weak "priming" stimulus that caused CaM translocation, CREB phosphorylation caused by a subsequent stimulus was significantly faster, more sensitive to Ca(2+) elevation, and less specifically dependent on Ca(2+) influx through L-type channels. CaM translocation not only supports rapid signaling to the nucleus, but also could provide a "memory" for facilitatory effects of repeated neural activity, seen in altered phosphorylated CREB dynamics and Ca(2+) channel dependence.
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Affiliation(s)
- P G Mermelstein
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
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