RESUMEN
Microsatellite expansion disorders are pathologically characterized by RNA foci formation and repeat-associated non-AUG (RAN) translation. However, their underlying pathomechanisms and regulation of RAN translation remain unknown. We report that expression of expanded UGGAA (UGGAAexp) repeats, responsible for spinocerebellar ataxia type 31 (SCA31) in Drosophila, causes neurodegeneration accompanied by accumulation of UGGAAexp RNA foci and translation of repeat-associated pentapeptide repeat (PPR) proteins, consistent with observations in SCA31 patient brains. We revealed that motor-neuron disease (MND)-linked RNA-binding proteins (RBPs), TDP-43, FUS, and hnRNPA2B1, bind to and induce structural alteration of UGGAAexp. These RBPs suppress UGGAAexp-mediated toxicity in Drosophila by functioning as RNA chaperones for proper UGGAAexp folding and regulation of PPR translation. Furthermore, nontoxic short UGGAA repeat RNA suppressed mutated RBP aggregation and toxicity in MND Drosophila models. Thus, functional crosstalk of the RNA/RBP network regulates their own quality and balance, suggesting convergence of pathomechanisms in microsatellite expansion disorders and RBP proteinopathies.
Asunto(s)
Proteínas de Unión al ADN/genética , Ribonucleoproteína Heterogénea-Nuclear Grupo A-B/genética , Repeticiones de Microsatélite/genética , Enfermedad de la Neurona Motora/genética , Pliegue del ARN/genética , Proteína FUS de Unión a ARN/genética , Ataxias Espinocerebelosas/genética , Anciano , Anciano de 80 o más Años , Animales , Animales Modificados Genéticamente , Expansión de las Repeticiones de ADN , Proteínas de Drosophila/genética , Drosophila melanogaster , Femenino , Humanos , Masculino , Persona de Mediana Edad , Chaperonas Moleculares/genética , Células PC12 , Biosíntesis de Proteínas/genética , Proteínas de Unión al ARN/genética , RatasRESUMEN
To understand molecular responses to salt stress in soybean (Glycine max [L.] Merr.), we identified 106 salt-inducible soybean genes that expressed differentially at 72 h after 100 mM NaCl treatment using the cDNA-amplified fragment length polymorphism (AFLP) method. The genes were designated as G. max Transcript-Derived Fragments (GmTDFs). Among these genes, we characterized a soybean gene GmTDF-5 that encoded an unknown protein of 367 amino acids. The GmTDF-5 protein was a putative cytosolic protein with two leucine-zipper motifs at the N-terminal and was calculated as 40.7 kDa. Southern blot analysis indicated that GmTDF-5 presents as an intron-less single gene on soybean genome and possibly distributes narrowly throughout the higher plants. By 100 mM NaCl treatment, the gene expression of GmTDF-5 was induced in the stem and lower-expanded leaf, and the amount of mRNA increased 5.1- and 2.0-fold up to 72 h, respectively. Interestingly, GmTDF-5 expression in the upper-leaf appeared dramatically with 10.0-fold increase at 72 h after the salt stress, but not until 48 h. Hyperosmotic pressure (mannitol treatment) and dehydration also caused the increases similar to NaCl treatment in the levels of GmTDF-5 expression. These results suggest that GmTDF-5 might be a novel cytosolic leucine-zipper-like protein functioning in mature organs of soybean shoot against water-potential changes.
Asunto(s)
Glycine max/efectos de los fármacos , Cloruro de Sodio/farmacología , Proteínas de Soja/genética , Ácido Abscísico/farmacología , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Deshidratación , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Genes de Plantas/genética , Interacciones Hidrofóbicas e Hidrofílicas , Manitol/farmacología , Datos de Secuencia Molecular , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/genética , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genética , Tallos de la Planta/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ácido Salicílico/farmacología , Análisis de Secuencia de ADN , Proteínas de Soja/química , Glycine max/genéticaRESUMEN
DNA has been recognized as an ideal material for bottom-up construction of nanometer scale structures by self-assembly. The generation of sequences optimized for unique self-assembly (GENESUS) program reported here is a straightforward method for generating sets of strand sequences optimized for self-assembly of arbitrarily designed DNA nanostructures by a generate-candidates-and-choose-the-best strategy. A scalable procedure to prepare single-stranded DNA having arbitrary sequences is also presented. Strands for the assembly of various structures were designed and successfully constructed, validating both the program and the procedure.