RESUMO
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.
Assuntos
Ansiedade/induzido quimicamente , Lobo Frontal/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Proteínas Sensoras de Cálcio Neuronal/genética , Proteínas Sensoras de Cálcio Neuronal/metabolismo , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Ácido Valproico/efeitos adversos , Animais , Ansiedade/genética , Ansiedade/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Regulação para Baixo , Glicogênio Sintase Quinase 3 beta/genética , Células HEK293 , Humanos , Masculino , Camundongos , Células PC12 , Ratos , Comportamento Social , Regulação para Cima , Ácido Valproico/administração & dosagemRESUMO
Neuronal calcium sensor-1 or Frequenin is a calcium sensor widely expressed in the nervous system, with roles in neurotransmission, neurite outgrowth, synaptic plasticity, learning, and motivated behaviours. Neuronal calcium sensor-1 has been implicated in neuropsychiatric disorders including autism spectrum disorder, schizophrenia, and bipolar disorder. However, the role of neuronal calcium sensor-1 in behavioural phenotypes and brain changes relevant to autism spectrum disorder have not been evaluated. We show that neuronal calcium sensor-1 deletion in the mouse leads to a mild deficit in social approach and impaired displaced object recognition without affecting social interactions, behavioural flexibility, spatial reference memory, anxiety-like behaviour, or sensorimotor gating. Morphologically, neuronal calcium sensor-1 deletion leads to increased dendritic arbour complexity in the frontal cortex. At the level of hippocampal synaptic plasticity, neuronal calcium sensor-1 deletion leads to a reduction in long-term potentiation in the dentate gyrus, but not area Cornu Ammonis 1. Metabotropic glutamate receptor-induced long-term depression was unaffected in both dentate and Cornu Ammonis 1. These studies identify roles for neuronal calcium sensor-1 in specific subregions of the brain including a phenotype relevant to neuropsychiatric disorders.
Assuntos
Comportamento de Escolha/fisiologia , Cognição/fisiologia , Potenciação de Longa Duração/genética , Proteínas Sensoras de Cálcio Neuronal/genética , Plasticidade Neuronal/genética , Neuropeptídeos/genética , Reconhecimento Psicológico/fisiologia , Animais , Ansiedade/genética , Região CA1 Hipocampal/fisiologia , Giro Denteado/fisiopatologia , Lobo Frontal/patologia , Camundongos , Camundongos Knockout , Receptores de Glutamato Metabotrópico , Filtro Sensorial/genética , Comportamento Social , Interação Social , Memória Espacial/fisiologiaRESUMO
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.
Assuntos
Antozoários/crescimento & desenvolvimento , Cálcio/metabolismo , Calmodulina/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Larva/metabolismo , Metamorfose Biológica , Proteínas Sensoras de Cálcio Neuronal/metabolismo , Sequência de Aminoácidos , Animais , Antozoários/genética , Northern Blotting , Calmodulina/genética , Cromatografia de Afinidade , DNA Complementar/genética , Perfilação da Expressão Gênica , Hibridização In Situ , Larva/citologia , Larva/genética , Dados de Sequência Molecular , Proteínas Sensoras de Cálcio Neuronal/genética , Ligação Proteica , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de AminoácidosRESUMO
We have developed a protocol to produce large quantities of high purity myristoylated and non-myristoylated neuronal calcium sensor 1 (NCS-1) protein. NCS-1 is a member of the neuronal calcium sensor (NCS) family and plays an important role in modulating G-protein signaling and exocytosis pathways in cells. Many of these functions are calcium-dependent and require NCS-1 to be modified with an N-terminal myristoyl moiety. In our system, a C-terminally 6x His-tagged variant of NCS-1 was co-expressed with yeast N-myristoyltransferase (NMT) in ZYP-5052 auto-induction media supplemented with sodium myristate (100-200 microM). With optimized growth conditions and a high capacity metal affinity purification scheme, >50mg of homogenous myristoylated NCS-1 is obtained from 1L of culture in a single step. The properties of the C-terminally tagged NCS-1 variants are indistinguishable from those reported for untagged NCS-1. Using this system, we have also isolated and characterized mutant NCS-1 proteins that have attenuated (NCS-1 E120Q) and abrogated (NCS-1 DeltaEF) ability to bind calcium. The large quantities of NCS-1 proteins isolated from small culture volumes of auto-inducible media will provide the necessary reagents for further biochemical and structural characterization. The affinity tag at the C-terminus of the protein provides a suitable reagent for easily identifying binding partners of the various NCS-1 constructs. Additionally, this method could be used to produce other recombinant proteins of the NCS family, and may be extended to express and isolate myristoylated variants of other proteins.