NCS-1 protein regulates TRPA1 channel through the PI3K pathway in breast cancer and neuronal cells.

The physical and functional interaction between transient receptor potential channel ankyrin 1 (TRPA1) and neuronal calcium sensor 1 (NCS-1) was assessed. NCS-1 is a calcium (Ca2+) sensor found in many tissues, primarily neurons, and TRPA1 is a Ca2+ channel involved not only in thermal and pain sensation but also in conditions such as cancer and chemotherapy-induced peripheral neuropathy, in which NCS-1 is also a regulatory component.We explored the interactions between these two proteins by employing western blot, qRT-PCR, co-immunoprecipitation, Ca2+ transient monitoring with Fura-2 spectrophotometry, and electrophysiology assays in breast cancer cells (MDA-MB-231) with different levels of NCS-1 expression and neuroblastoma cells (SH-SY5Y).Our findings showed that the expression of TRPA1 was directly correlated with NCS-1 levels at both the protein and mRNA levels. Additionally, we found a physical and functional association between these two proteins. Physically, the NCS-1 and TRPA1 co-immunoprecipitate. Functionally, NCS-1 enhanced TRPA1-dependent Ca2+ influx, current density, open probability, and conductance, where the functional effects depended on PI3K. Conclusion: NCS-1 appears to act not only as a Ca2+ sensor but also modulates TRPA1 protein expression and channel function in a direct fashion through the PI3K pathway. These results contribute to understanding how Ca2+ homeostasis is regulated and provides a mechanism underlying conditions where Ca2+ dynamics are compromised, including breast cancer. With a cellular pathway identified, targeted treatments can be developed for breast cancer and neuropathy, among other related diseases.

[Neuronal Calcium Sensor-1: A Zinc/Redox-Dependent Protein of Nervous System Signaling Pathways].

Intracellular calcium signaling is involved in regulating the key functional mechanisms of the nervous system. The control of neuronal excitability and plasticity by calcium ions underlies the mechanisms of higher nervous activity, and the mechanisms of this control are of particular interest to researchers. A family of highly specialized neuronal proteins described in recent decades can translate the information contained in calcium signals into the regulation of channels, enzymes, receptors, and transcription factors. Neuronal calcium sensor-1 (NCS-1) is the most common member of the family, which is intensely expressed in central nervous system (CNS) cells; and controls several vital processes, such as neuronal growth and survival, reception, neurotransmission, and synaptic plasticity. In addition to calcium ions, NCS-1 can bind the so-called mobile, or signaling intracellular zinc, an increased concentration of which is a characteristic feature of cells in oxidative stress. Zinc coordination under these conditions stimulates NCS-1 oxidation to form a disulfide dimer (dNCS-1) with altered functional properties. A combined effect of mobile zinc and an increased redox potential of the medium can thus induce aberrant NCS-1 activity, including signals that promote survival of neuronal cells or induce their apoptosis and, consequently, the development of neurodegenerative processes. The review details the localization, expression regulation, structure, and molecular properties of NCS-1 and considers the current data on its signaling activity in health and disease, including zinc-dependent redox regulation cascades.

Molecular tuning of calcium dependent processes by neuronal calcium sensor proteins in the retina.

Vertebrate photoreceptor cells are exquisite light detectors operating under very dim and bright illumination mediated by phototransduction, which is under control of the two secondary messengers cGMP and Ca2+. Feedback mechanisms enable photoreceptor cells to regain their responsiveness after light stimulation and involve neuronal Ca2+-sensor proteins, named GCAPs (guanylate cyclase-activating proteins) and recoverins. This review compares the diversity in Ca2+-related signaling mediated by GCAP and recoverin variants that exhibit differences in Ca2+-sensing, protein conformational changes, myristoyl switch mechanisms, diversity in divalent cation binding and dimer formation. In summary, both subclasses of neuronal Ca2+-sensor proteins contribute to a complex signaling network in rod and cone cells, which is perfectly suited to match the requirements for sensitive cell responses and maintaining this responsiveness in the presence of different background light intensities.

Neuronal Calcium Sensor-1 Protects Cortical Neurons from Hyperexcitation and Ca2+ Overload during Ischemia by Protecting the Population of GABAergic Neurons.

A defection of blood circulation in the brain leads to ischemia, damage, and the death of nerve cells. It is known that individual populations of GABAergic neurons are the least resistant to the damaging factors of ischemia and therefore they die first of all, which leads to impaired inhibition in neuronal networks. To date, the neuroprotective properties of a number of calcium-binding proteins (calbindin, calretinin, and parvalbumin), which are markers of GABAergic neurons, are known. Neuronal calcium sensor-1 (NCS-1) is a signaling protein that is expressed in all types of neurons and is involved in the regulation of neurotransmission. The role of NCS-1 in the protection of neurons and especially their individual populations from ischemia and hyperexcitation has not been practically studied. In this work, using the methods of fluorescence microscopy, vitality tests, immunocytochemistry, and PCR analysis, the molecular mechanisms of the protective action of NCS-1 in ischemia/reoxygenation and hyperammonemia were established. Since NCS-1 is most expressed in GABAergic neurons, the knockdown of this protein with siRNA led to the most pronounced consequences in GABAergic neurons. The knockdown of NCS-1 (NCS-1-KD) suppressed the basic expression of protective proteins without significantly reducing cell viability. However, ischemia-like conditions (oxygen-glucose deprivation, OGD) and subsequent 24-h reoxygenation led to a more massive activation of apoptosis and necrosis in neurons with NCS-1-KD, compared to control cells. The mass death of NCS-1-KD cells during OGD and hyperammonemia has been associated with the induction of a more pronounced network hyperexcitation symptom, especially in the population of GABAergic neurons, leading to a global increase in cytosolic calcium ([Ca2+]i). The symptom of hyperexcitation of neurons with NCS-1-KD correlated with a decrease in the level of expression of the calcium-binding protein-parvalbumin. This was accompanied by an increase in the expression of excitatory ionotropic glutamate receptors, N-methyl-D-aspartate and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (NMDAR and AMPAR) against the background of suppression of the expression of glutamate decarboxylase (synthesis of γ-aminobutyric acid).

Zinc Modulation of Neuronal Calcium Sensor Proteins: Three Modes of Interaction with Different Structural Outcomes.

Neuronal calcium sensors (NCSs) are the family of EF-hand proteins mediating Ca2+-dependent signaling pathways in healthy neurons and neurodegenerative diseases. It was hypothesized that the calcium sensor activity of NCSs can be complemented by sensing fluctuation of intracellular zinc, which could further diversify their function. Here, using a set of biophysical techniques, we analyzed the Zn2+-binding properties of five proteins belonging to three different subgroups of the NCS family, namely, VILIP1 and neurocalcin-δ/NCLD (subgroup B), recoverin (subgroup C), as well as GCAP1 and GCAP2 (subgroup D). We demonstrate that each of these proteins is capable of coordinating Zn2+ with a different affinity, stoichiometry, and structural outcome. In the absence of calcium, recoverin and VILIP1 bind two zinc ions with submicromolar affinity, and the binding induces pronounced conformational changes and regulates the dimeric state of these proteins without significant destabilization of their structure. In the presence of calcium, recoverin binds zinc with slightly decreased affinity and moderate conformational outcome, whereas VILIP1 becomes insensitive to Zn2+. NCALD binds Zn2+ with micromolar affinity, but the binding induces dramatic destabilization and aggregation of the protein. In contrast, both GCAPs demonstrate low-affinity binding of zinc independent of calcium, remaining relatively stable even at submillimolar Zn2+ concentrations. Based on these data, and the results of structural bioinformatics analysis, NCSs can be divided into three categories: (1) physiological Ca2+/Zn2+ sensor proteins capable of binding exchangeable (signaling) zinc (recoverin and VILIP1), (2) pathological Ca2+/Zn2+ sensors responding only to aberrantly high free zinc concentrations by denaturation and aggregation (NCALD), and (3) Zn2+-resistant, Ca2+ sensor proteins (GCAP1, GCAP2). We suggest that NCS proteins may therefore govern the interconnection between Ca2+-dependent and Zn2+-dependent signaling pathways in healthy neurons and zinc cytotoxicity-related neurodegenerative diseases, such as Alzheimer's disease and glaucoma.

Functional Interaction between Transient Receptor Potential V4 Channel and Neuronal Calcium Sensor 1 and the Effects of Paclitaxel.

Neuronal calcium sensor 1 (NCS1), a calcium-binding protein, and transient receptor potential V4 (TRPV4), a plasma membrane calcium channel, are fundamental in the regulation of calcium homeostasis. The interactions of these proteins and their regulation by paclitaxel (PTX) were investigated using biochemical, pharmacological, and electrophysiological approaches in both a breast cancer epithelial cell model and a neuronal model. TRPV4 and NCS1 reciprocally immunoprecipitated each other, suggesting that they make up a signaling complex. The functional consequence of this physical association was that TRPV4 currents increased with increased NCS1 expression. Calcium fluxes through TRPV4 correlated with the magnitude of TRPV4 currents, and these calcium fluxes depended on NCS1 expression levels. Exposure to PTX amplified the acute effects of TRPV4 expression, currents, and calcium fluxes but decreased the expression of NCS1. These findings augment the understanding of the properties of TRPV4, the role of NCS1 in the regulation of TRPV4, and the cellular mechanisms of PTX-induced neuropathy. SIGNIFICANCE STATEMENT: TRPV4 and NCS1 physically and functionally interact. Increased expression of NCS1 enhances TRPV4-dependent currents, which are further amplified by treatment with the chemotherapeutic drug paclitaxel, an effect associated with adverse effects of chemotherapy, including neuropathy.

Neurochemical abnormalities in the hippocampus of male rats displaying audiogenic seizures, a genetic model of epilepsy.

BACKGROUND: Epilepsy is a disorder characterized by recurrent seizures that affects 1% of the population. However, the neurochemical alterations observed in epilepsy are not fully understood. There are different animal models of epilepsy, such as genetic or drug induced. In the present study, we utilize Wistar Audiogenic Rats (WAR), a murine strain that develops seizures in response to high intensity audio stimulation, in order to investigate abnormalities in glutamatergic and GABAergic systems. METHODS: Synaptosomes and glial plasmalemmal vesicles were prepared from hippocampus and cortex, respectively. Glutamate and GABA release and uptake were assayed by monitoring the fluorescence and using L-[3H]-radiolabeled compounds. Glutamate and calcium concentration in the synaptosomes were also measured. The expression of neuronal calcium sensor 1 (NCS-1) was determined by western blot. RESULTS: Glutamate and GABA release evoked by KCl was decreased in WAR compared to control Wistar rats. Calcium independent release was not considerably different in both groups. The total amount of glutamate of synaptosomes, as well as glutamate uptake by synaptosomes and GPV were also decreased in WAR in comparison with the controls. In addition, [Ca2+]i of hippocampal synaptosomes, as well as NCS-1 expression in the hippocampus, were increased in WAR in comparison with controls. CONCLUSION: In conclusion, our results suggest that WAR have important alterations in the glutamatergic and GABAergic pathways, as well as an increased expression of NCS-1 in the hippocampus and inferior colliculus. These alterations may be linked to the spreading of hyperexcitability and recruitment of various brain regions.

Disorder in a two-domain neuronal Ca2+-binding protein regulates domain stability and dynamics using ligand mimicry.

Understanding the interplay between sequence, structure and function of proteins has been complicated in recent years by the discovery of intrinsically disordered proteins (IDPs), which perform biological functions in the absence of a well-defined three-dimensional fold. Disordered protein sequences account for roughly 30% of the human proteome and in many proteins, disordered and ordered domains coexist. However, few studies have assessed how either feature affects the properties of the other. In this study, we examine the role of a disordered tail in the overall properties of the two-domain, calcium-sensing protein neuronal calcium sensor 1 (NCS-1). We show that loss of just six of the 190 residues at the flexible C-terminus is sufficient to severely affect stability, dynamics, and folding behavior of both ordered domains. We identify specific hydrophobic contacts mediated by the disordered tail that may be responsible for stabilizing the distal N-terminal domain. Moreover, sequence analyses indicate the presence of an LSL-motif in the tail that acts as a mimic of native ligands critical to the observed order-disorder communication. Removing the disordered tail leads to a shorter life-time of the ligand-bound complex likely originating from the observed destabilization. This close relationship between order and disorder may have important implications for how investigations into mixed systems are designed and opens up a novel avenue of drug targeting exploiting this type of behavior.

A Novel Approach to Bacterial Expression and Purification of Myristoylated Forms of Neuronal Calcium Sensor Proteins.

N-terminal myristoylation is a common co-and post-translational modification of numerous eukaryotic and viral proteins, which affects their interaction with lipids and partner proteins, thereby modulating various cellular processes. Among those are neuronal calcium sensor (NCS) proteins, mediating transduction of calcium signals in a wide range of regulatory cascades, including reception, neurotransmission, neuronal growth and survival. The details of NCSs functioning are of special interest due to their involvement in the progression of ophthalmological and neurodegenerative diseases and their role in cancer. The well-established procedures for preparation of native-like myristoylated forms of recombinant NCSs via their bacterial co-expression with N-myristoyl transferase from Saccharomyces cerevisiae often yield a mixture of the myristoylated and non-myristoylated forms. Here, we report a novel approach to preparation of several NCSs, including recoverin, GCAP1, GCAP2, neurocalcin δ and NCS-1, ensuring their nearly complete N-myristoylation. The optimized bacterial expression and myristoylation of the NCSs is followed by a set of procedures for separation of their myristoylated and non-myristoylated forms using a combination of hydrophobic interaction chromatography steps. We demonstrate that the refolded and further purified myristoylated NCS-1 maintains its Са2+-binding ability and stability of tertiary structure. The developed approach is generally suited for preparation of other myristoylated proteins.

Neuronal Calcium Sensor 1 is up-regulated in response to stress to promote cell survival and motility in cancer cells.

Changes in intracellular calcium (Ca2+ ) signaling can modulate cellular machinery required for cancer progression. Neuronal calcium sensor 1 (NCS1) is a ubiquitously expressed Ca2+ -binding protein that promotes tumor aggressiveness by enhancing cell survival and metastasis. However, the underlying mechanism by which NCS1 contributes to increased tumor aggressiveness has yet to be identified. In this study, we aimed to determine (a) whether NCS1 expression changes in response to external stimuli, (b) the importance of NCS1 for cell survival and migration, and (c) the cellular mechanism(s) through which NSC1 modulates these outcomes. We found that NCS1 abundance increases under conditions of stress, most prominently after stimulation with the pro-inflammatory cytokine tumor necrosis factor α, in a manner dependent on nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). We found that NFκB signaling is activated in human breast cancer tissue, which was accompanied by an increase in NCS1 mRNA expression. Further exploration into the relevance of NCS1 in breast cancer progression showed that knockout of NCS1 (NCS1 KO) caused decreased cell survival and motility, increased baseline intracellular Ca2+ levels, and decreased inositol 1,4,5-trisphosphate-mediated Ca2+ responses. Protein kinase B (Akt) activity was decreased in NCS1 KO cells, which could be rescued by buffering intracellular Ca2+ . Conversely, Akt activity was increased in cells overexpressing NCS1 (NCS1 OE). We therefore conclude that NCS1 acts as cellular stress response protein up-regulated by stress-induced NFκB signaling and that NCS1 influences cell survival and motility through effects on Ca2+ signaling and Akt pathway activation.

APOL1 C-Terminal Variants May Trigger Kidney Disease through Interference with APOL3 Control of Actomyosin.

The C-terminal variants G1 and G2 of apolipoprotein L1 (APOL1) confer human resistance to the sleeping sickness parasite Trypanosoma rhodesiense, but they also increase the risk of kidney disease. APOL1 and APOL3 are death-promoting proteins that are partially associated with the endoplasmic reticulum and Golgi membranes. We report that in podocytes, either APOL1 C-terminal helix truncation (APOL1Δ) or APOL3 deletion (APOL3KO) induces similar actomyosin reorganization linked to the inhibition of phosphatidylinositol-4-phosphate [PI(4)P] synthesis by the Golgi PI(4)-kinase IIIB (PI4KB). Both APOL1 and APOL3 can form K+ channels, but only APOL3 exhibits Ca2+-dependent binding of high affinity to neuronal calcium sensor-1 (NCS-1), promoting NCS-1-PI4KB interaction and stimulating PI4KB activity. Alteration of the APOL1 C-terminal helix triggers APOL1 unfolding and increased binding to APOL3, affecting APOL3-NCS-1 interaction. Since the podocytes of G1 and G2 patients exhibit an APOL1Δ or APOL3KO-like phenotype, APOL1 C-terminal variants may induce kidney disease by preventing APOL3 from activating PI4KB, with consecutive actomyosin reorganization of podocytes.

Contribution of neuronal calcium sensor 1 (Ncs-1) to anxiolytic-like and social behavior mediated by valproate and Gsk3 inhibition.

Peripheral biomarker and post-mortem brains studies have shown alterations of neuronal calcium sensor 1 (Ncs-1) expression in people with bipolar disorder or schizophrenia. However, its engagement by psychiatric medications and potential contribution to behavioral regulation remains elusive. We investigated the effect on Ncs-1 expression of valproic acid (VPA), a mood stabilizer used for the management of bipolar disorder. Treatment with VPA induced Ncs-1 gene expression in cell line while chronic administration of this drug to mice increased both Ncs-1 protein and mRNA levels in the mouse frontal cortex. Inhibition of histone deacetylases (HDACs), a known biochemical effect of VPA, did not alter the expression of Ncs-1. In contrast, pharmacological inhibition or genetic downregulation of glycogen synthase kinase 3ß (Gsk3ß) increased Ncs-1 expression, whereas overexpression of a constitutively active Gsk3ß had the opposite effect. Moreover, adeno-associated virus-mediated Ncs-1 overexpression in mouse frontal cortex caused responses similar to those elicited by VPA or lithium in tests evaluating social and mood-related behaviors. These findings indicate that VPA increases frontal cortex Ncs-1 gene expression as a result of Gsk3 inhibition. Furthermore, behavioral changes induced by Ncs-1 overexpression support a contribution of this mechanism in the regulation of behavior by VPA and potentially other psychoactive medications inhibiting Gsk3 activity.

Membrane Binding of Neuronal Calcium Sensor-1: Highly Specific Interaction with Phosphatidylinositol-3-Phosphate.

Neuronal calcium sensors are a family of N-terminally myristoylated membrane-binding proteins possessing a different intracellular localization and thereby targeting unique signaling partner(s). Apart from the myristoyl group, the membrane attachment of these proteins may be modulated by their N-terminal positively charged residues responsible for specific recognition of the membrane components. Here, we examined the interaction of neuronal calcium sensor-1 (NCS-1) with natural membranes of different lipid composition as well as individual phospholipids in form of multilamellar liposomes or immobilized monolayers and characterized the role of myristoyl group and N-terminal lysine residues in membrane binding and phospholipid preference of the protein. NCS-1 binds to photoreceptor and hippocampal membranes in a Ca2+-independent manner and the binding is attenuated in the absence of myristoyl group. Meanwhile, the interaction with photoreceptor membranes is less dependent on myristoylation and more sensitive to replacement of K3, K7, and/or K9 of NCS-1 by glutamic acid, reflecting affinity of the protein to negatively charged phospholipids. Consistently, among the major phospholipids, NCS-1 preferentially interacts with phosphatidylserine and phosphatidylinositol with micromolar affinity and the interaction with the former is inhibited upon mutating of N-terminal lysines of the protein. Remarkably, NCS-1 demonstrates pronounced specific binding to phosphoinositides with high preference for phosphatidylinositol-3-phosphate. The binding does not depend on myristoylation and, unexpectedly, is not sensitive to the charge inversion mutations. Instead, phosphatidylinositol-3-phosphate can be recognized by a specific site located in the N-terminal region of the protein. These data provide important novel insights into the general mechanism of membrane binding of NCS-1 and its targeting to specific phospholipids ensuring involvement of the protein in phosphoinositide-regulated signaling pathways.

NCS-1 expression is higher in basal breast cancers and regulates calcium influx and cytotoxic responses to doxorubicin.

Neuronal calcium sensor-1 (NCS-1) is a positive modulator of IP3 receptors and was recently associated with poorer survival in breast cancers. However, the association between NCS-1 and breast cancer molecular subtypes and the effects of NCS-1 silencing on calcium (Ca2+ ) signaling in breast cancer cells remain unexplored. Herein, we report for the first time an increased expression of NCS-1 in breast cancers of the basal molecular subtype, a subtype associated with poor prognosis. Using MDA-MB-231 basal breast cancer cells expressing the GCaMP6m Ca2+ indicator, we showed that NCS-1 silencing did not result in major changes in cytosolic free Ca2+ increases as a result of endoplasmic reticulum Ca2+ store mobilization. However, NCS-1 silencing suppressed unstimulated basal Ca2+ influx. NCS-1 silencing in MDA-MB-231 cells also promoted necrotic cell death induced by the chemotherapeutic drug doxorubicin (1 µm). The effect of NCS-1 silencing on cell death was phenocopied by silencing of ORAI1, a Ca2+ store-operated Ca2+ channel that maintains Ca2+ levels in the endoplasmic reticulum Ca2+ store and whose expression was significantly positively correlated with NCS-1 in clinical breast cancer samples. This newly identified association between NCS-1 and basal breast cancers, together with the identification of the role of NCS-1 in the regulation of the effects of doxorubicin in MDA-MB-231 breast cancer cells, suggests that NCS-1 and/or pathways regulated by NCS-1 may be important in the treatment of basal breast cancers in women.

Cav2.3 channels contribute to dopaminergic neuron loss in a model of Parkinson's disease.

Degeneration of dopaminergic neurons in the substantia nigra causes the motor symptoms of Parkinson's disease. The mechanisms underlying this age-dependent and region-selective neurodegeneration remain unclear. Here we identify Cav2.3 channels as regulators of nigral neuronal viability. Cav2.3 transcripts were more abundant than other voltage-gated Ca2+ channels in mouse nigral neurons and upregulated during aging. Plasmalemmal Cav2.3 protein was higher than in dopaminergic neurons of the ventral tegmental area, which do not degenerate in Parkinson's disease. Cav2.3 knockout reduced activity-associated nigral somatic Ca2+ signals and Ca2+-dependent after-hyperpolarizations, and afforded full protection from degeneration in vivo in a neurotoxin Parkinson's mouse model. Cav2.3 deficiency upregulated transcripts for NCS-1, a Ca2+-binding protein implicated in neuroprotection. Conversely, NCS-1 knockout exacerbated nigral neurodegeneration and downregulated Cav2.3. Moreover, NCS-1 levels were reduced in a human iPSC-model of familial Parkinson's. Thus, Cav2.3 and NCS-1 may constitute potential therapeutic targets for combatting Ca2+-dependent neurodegeneration in Parkinson's disease.

Characterization of NCS1-InsP3R1 interaction and its functional significance.

Inositol 1,4,5-trisphosphate receptors (InsP3Rs) are endoplasmic reticulum-localized channels that mediate Ca2+ release from the endoplasmic reticulum into the cytoplasm. We previously reported that an EF-hand Ca2+-binding protein, neuronal calcium sensor 1 (NCS1), binds to the InsP3R and thereby increases channel open probability, an event associated with chemotherapy-induced peripheral neuropathy. However, the exact NCS1-binding site on InsP3R remains unknown. Using protein docking, co-immunoprecipitation, and blocking peptides, we mapped the NCS1-binding site to residues 66-110 on the suppressor domain of InsP3R type 1 (InsP3R1). We also identified Leu-89, a residue in the hydrophobic pocket of NCS1, as being critical for facilitating the NCS1-InsP3R1 interaction. Overexpression of WT NCS1 in MDA-MB231 breast cancer cells increased Ca2+ signaling and survival, whereas overexpression of Leu-89 NCS1 variants decreased Ca2+ signaling and survival, further suggesting the importance of this residue in the NCS1-InsP3R1 interaction. In conclusion, we show that NCS1-InsP3R1 interaction enhances intracellular Ca2+ signaling in cells and can be modulated by altering or occluding the hydrophobic pocket of NCS1. This improved understanding of the NCS1-InsP3R1 interaction may facilitate the development of management strategies for diseases resulting from aberrant NCS1 expression.

Insights into real-time chemical processes in a calcium sensor protein-directed dynamic library.

Dynamic combinatorial chemistry (DCC) has proven its potential in drug discovery speeding the identification of modulators of biological targets. However, the exchange chemistries typically take place under specific reaction conditions, with limited tools capable of operating under physiological parameters. Here we report a catalyzed protein-directed DCC working at low temperatures that allows the calcium sensor NCS-1 to find the best ligands in situ. Ultrafast NMR identifies the reaction intermediates of the acylhydrazone exchange, tracing the molecular assemblies and getting a real-time insight into the essence of DCC processes at physiological pH. Additionally, NMR, X-ray crystallography and computational methods are employed to elucidate structural and mechanistic aspects of the molecular recognition event. The DCC approach leads us to the identification of a compound stabilizing the NCS-1/Ric8a complex and whose therapeutic potential is proven in a Drosophila model of disease with synaptic alterations.

Current Understanding of the Role of Neuronal Calcium Sensor 1 in Neurological Disorders.

Neuronal calcium sensor 1 (NCS-1) is a high-affinity calcium-binding protein and its ubiquitous expression in the nervous system implies a wide range of functions. To date, it has been implicated in regulation of calcium channels in both axonal growth cones and presynaptic terminals, pre- and postsynaptic plasticity mechanisms, learning and memory behaviors, dopaminergic signaling, and axonal regeneration. This review summarizes these functions and relates them to several diseases in which NCS-1 plays a role, such as schizophrenia and bipolar disorder, X-linked mental retardation and fragile X syndrome, and spinal cord injury. Many questions remain unanswered about the role of NCS-1 in these diseases, particularly as the genetic factors that control NCS-1 expression in both normal and diseased states are still poorly understood. The review further identifies the therapeutic potential of manipulating the interaction of NCS-1 with its many targets and suggests directions for future research on the role of NCS-1 in these disorders.