RESUMEN
Autism (MIM 209850) is a multifactorial disorder with a broad clinical presentation. A number of high-confidence ASD risk genes are known; however, the contribution of non-genetic environmental factors towards ASD remains largely uncertain. Here, we present a bioinformatics resource of genetic and induced models of ASD developed using a shared annotation platform. Using this data, we depict the intricate trends in the research approaches to analyze rodent models of ASD. We identify the top 30 most frequently studied phenotypes extracted from rodent models of ASD based on 787 publications. As expected, many of these include animal model equivalents of the "core" phenotypes associated with ASD, such as impairments in social behavior and repetitive behavior, as well as several comorbid features of ASD including anxiety, seizures, and motor-control deficits. These phenotypes have also been studied in models based on a broad range of environmental inducers present in the database, of which gestational exposure to valproic acid (VPA) and maternal immune activation models comprising lipopolysaccharide (LPS) and poly I:C are the most studied. In our unique dataset of rescue models, we identify 24 pharmaceutical agents tested on established models derived from various ASD genes and CNV loci for their efficacy in mitigating symptoms relevant for ASD. As a case study, we analyze a large collection of Shank3 mouse models providing a high-resolution view of the in vivo role of this high-confidence ASD gene, which is the gateway towards understanding and dissecting the heterogeneous phenotypes seen in single-gene models of ASD. The trends described in this study could be useful for researchers to compare ASD models and to establish a complete profile for all relevant animal models in ASD research.
Asunto(s)
Trastorno Autístico/genética , Modelos Animales de Enfermedad , Fenotipo , Animales , Trastorno Autístico/tratamiento farmacológico , Trastorno Autístico/patología , Bases de Datos Genéticas , Ratones , Ratas , Investigación Biomédica Traslacional/normasRESUMEN
AutDB is a deeply annotated resource for exploring the impact of genetic variations associated with autism spectrum disorders (ASD). First released in 2007, AutDB has evolved into a multi-modular resource of diverse types of genetic and functional evidence related to ASD. Current modules include: Human Gene, which annotates all ASD-linked genes and their variants; Animal Model, which catalogs behavioral, anatomical and physiological data from rodent models of ASD; Protein Interaction (PIN), which builds interactomes from direct relationships of protein products of ASD genes; and Copy Number Variant (CNV), which catalogs deletions and duplications of chromosomal loci identified in ASD. A multilevel data-integration strategy is utilized to connect the ASD genes to the components of the other modules. All information in this resource is manually curated by expert scientists from primary scientific publications and is referenced to source articles. AutDB is actively maintained with a rigorous quarterly data release schedule. As of June 2017, AutDB contains detailed annotations for 910 genes, 2197 CNV loci, 1060 rodent models and 38 296 PINs. With its widespread use by the research community, AutDB serves as a reference resource for analysis of large datasets, accelerating ASD research and potentially leading to targeted drug treatments. AutDB is available at http://autism.mindspec.org/autdb/Welcome.do.
Asunto(s)
Trastorno del Espectro Autista/genética , Bases de Datos Genéticas , Variación Genética , Animales , Trastorno del Espectro Autista/fisiopatología , Conducta Animal , Variaciones en el Número de Copia de ADN , Humanos , Ratones , Mapeo de Interacción de Proteínas , RatasRESUMEN
Histone acetylation plays a critical role during long-term memory formation. Several studies have demonstrated that the histone acetyltransferase (HAT) CBP is required during long-term memory formation, but the involvement of other HAT proteins has not been extensively investigated. The HATs CBP and p300 have at least 400 described interacting proteins including transcription factors known to play a role in long-term memory formation. Thus, CBP and p300 constitute likely candidates for transcriptional coactivators in memory formation. In this study, we took a loss-of-function approach to evaluate the role of p300 in long-term memory formation. We used conditional knock-out mice in which the deletion of p300 is restricted to the postnatal phase and to subregions of the forebrain. We found that p300 is required for the formation of long-term recognition memory and long-term contextual fear memory in the CA1 area of the hippocampus and cortical areas.
Asunto(s)
Encéfalo/fisiología , Memoria a Largo Plazo/fisiología , Factores de Transcripción p300-CBP/metabolismo , Animales , Western Blotting , Condicionamiento Clásico/fisiología , Miedo/fisiología , Inmunohistoquímica , Aprendizaje por Laberinto/fisiología , Ratones , Ratones Noqueados , Factores de Transcripción p300-CBP/deficiencia , Factores de Transcripción p300-CBP/genéticaRESUMEN
Tech is a RhoA guanine nucleotide exchange factor (GEF) that is highly enriched in hippocampal and cortical neurons. To help define its function, we have conducted studies aimed at identifying partner proteins that bind to its C-terminal PDZ ligand motif. Yeast two hybrid studies using the Tech C-terminal segment as bait identified MUPP1, a protein that contains 13 PDZ domains and has been localized to the post-synaptic compartment, as a candidate partner protein for Tech. Co-transfection of Tech and MUPP1 in human embryonic kidney 293 cells confirmed that these full-length proteins interact in a PDZ-dependent fashion. Furthermore, we confirmed that endogenous Tech co-precipitates with MUPP1, but not PSD-95, from hippocampal and cortical extracts prepared from rat brain. In addition, immunostaining of primary cortical cultures revealed co-localization of MUPP1 and Tech puncta in the vicinity of synapses. In assessing which PDZ domains of MUPP1 mediate binding to Tech, we found that Tech can bind to either PDZ domain 10 or 13 of MUPP1 as mutation of both these domains is needed to disrupt their interaction. Taken together, these findings demonstrate that Tech binds to MUPP1 and suggest that it regulates RhoA signaling pathways in the vicinity of synapses.
Asunto(s)
Proteínas Portadoras/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Dominios PDZ/fisiología , Sinapsis/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Animales , Proteínas Portadoras/genética , Línea Celular , Células Cultivadas , Factores de Intercambio de Guanina Nucleótido/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular , Proteínas del Tejido Nervioso/genética , Neuronas/metabolismo , Neuronas/fisiología , Ratas , Sinapsis/genética , Proteína de Unión al GTP rhoA/genéticaRESUMEN
Although it is well established that RhoA signaling pathways play key roles in regulating neuronal morphology, their involvement in other aspects of neuronal function has received little attention. Recent studies have elucidated a novel intracellular signaling pathway used by RhoA to elicit activation of serum response factor (SRF)-mediated transcription. In this pathway, activation of RhoA triggers nuclear translocation of the SRF co-activator, megakaryocytic acute leukemia (MAL). In assessing whether RhoA regulates transcription in neurons via this pathway, we have found that a constitutively active form of Tech (transcript-enriched in cortex and hippocampus), a RhoA guanine nucleotide exchange factor (GEF) that is expressed in forebrain neurons, stimulates SRF reporter activity in extracts of primary cortical cultures and induces nuclear translocation of MAL in cortical neurons. Both of these responses appear to be mediated by Tech's activation of RhoA as they are not mimicked by a mutant Tech construct lacking RhoA GEF activity and are blocked by C3 transferase, a selective inhibitor of RhoA. Furthermore, Tech-induced increases in SRF activity are suppressed by a dominant negative MAL construct. These findings demonstrate that RhoA signaling pathways are able to regulate transcription in neurons by triggering translocation of the SRF co-activator MAL.
Asunto(s)
Núcleo Celular/metabolismo , Corteza Cerebral/metabolismo , Proteínas de Unión al ADN/metabolismo , Neuronas/metabolismo , Proteínas de Fusión Oncogénica/metabolismo , Factor de Respuesta Sérica/metabolismo , Transducción de Señal/fisiología , Proteína de Unión al GTP rhoA/fisiología , Transporte Activo de Núcleo Celular/fisiología , Animales , Núcleo Celular/genética , Células Cultivadas , Leucemia Megacarioblástica Aguda/metabolismo , Ratones , Células 3T3 NIH , Proteínas de Unión al ARN/metabolismo , Factor de Respuesta Sérica/genética , Transducción de Señal/genética , Transactivadores , Transfección , Proteína de Unión al GTP rhoA/genéticaRESUMEN
Fumarase catalyzes the reversible conversion of fumarate to S- malate during the operation of the ubiquitous Kreb's cycle. Previous studies have shown that the active site includes side chains from three of the four subunits within the tetrameric enzyme. We used a clinically observed human mutation to narrow our search for potential catalytic groups within the fumarase active site. Offspring homozygous for the missense mutation, a G-955-C transversion in the fumarase gene, results in the substitution of a glutamine at amino acid 319 for the normal glutamic acid. To more fully understand the implications of this mutation, a single-step site-directed mutagenesis method was used to generate the homologous substitution at position 315 within fumarase C from Escherichia coli. Subsequent kinetic and X-ray crystal structure analyses show changes in the turnover number and the cocrystal structure with bound citrate.