Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027066 (myoclonus)
 4,275 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nova is a neuron-specific RNA binding protein targeted in patients with the autoimmune disorder paraneoplastic opsoclonus-myoclonus ataxia, which is characterized by failure of inhibition of brainstem and spinal motor systems. Here, we have biochemically confirmed the observation that splicing regulation of the inhibitory GABA(A) receptor gamma2 (GABA(A)Rgamma2) subunit pre-mRNA exon E9 is disrupted in mice lacking Nova-1. To elucidate the mechanism by which Nova-1 regulates GABA(A)Rgamma2 alternative splicing, we systematically screened minigenes derived from the GABA(A)Rgamma2 and human beta-globin genes for their ability to support Nova-dependent splicing in transient transfection assays. These studies demonstrate that Nova-1 acts directly on GABA(A)Rgamma2 pre-mRNA to regulate E9 splicing and identify an intronic region that is necessary and sufficient for Nova-dependent enhancement of exon inclusion, which we term the NISE (Nova-dependent intronic splicing enhancer) element. The NISE element (located 80 nucleotides upstream of the splice acceptor site of the downstream exon E10) is composed of repeats of the sequence YCAY, consistent with previous studies of the mechanism by which Nova binds RNA. Mutation of these repeats abolishes binding of Nova-1 to the RNA in vitro and Nova-dependent splicing regulation in vivo. These data provide a molecular basis for understanding Nova regulation of GABA(A)Rgamma2 alternative splicing and suggest that general dysregulation of Nova's splicing enhancer function may underlie the neurologic defects seen in Nova's absence.
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PMID:Nova regulates GABA(A) receptor gamma2 alternative splicing via a distal downstream UCAU-rich intronic splicing enhancer. 1280 7

Synaptic plasticity, the cellular correlate for learning and memory, involves signaling cascades in the dendritic spine. Extensive studies have shown that long-term potentiation (LTP) of the excitatory postsynaptic current (EPSC) through glutamate receptors is induced by activation of N-methyl-D-asparate receptor (NMDA-R)--the coincidence detector--and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII). Here we report that the same signaling pathway in the postsynaptic CA1 pyramidal neuron also causes LTP of the slow inhibitory postsynaptic current (sIPSC) mediated by metabotropic GABA(B) receptors (GABA(B)-Rs) and G protein-activated inwardly rectifying K(+) (GIRK) channels, both residing in dendritic spines as well as shafts. Indicative of intriguing differences in the regulatory mechanisms for excitatory and inhibitory synaptic plasticity, LTP of sIPSC but not EPSC was abolished in mice lacking Nova-2, a neuronal-specific RNA binding protein that is an autoimmune target in paraneoplastic opsoclonus myoclonus ataxia (POMA) patients with latent cancer, reduced inhibitory control of movements, and dementia.
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PMID:Common molecular pathways mediate long-term potentiation of synaptic excitation and slow synaptic inhibition. 1621 16