Abstract: MicroRNAs (miRNAs) are a novel class of small noncoding RNAs that modulate the expression of genes at the posttranscriptional level. These small molecules have been shown to be involved in cancer, apoptosis, and cell metabolism. In the present study we provide an informative profile of the expression of miRNAs in primary chronic lymphocytic leukemia (CLL) cells using 2 independent and quantitative methods: miRNA cloning and quantitative real-time-polymerase chain reaction (qRT-PCR) of mature miRNAs. Both approaches show that miR-21 and miR-155 are dramatically overexpressed in patients with CLL, although the corresponding genomic loci are not amplified. miR-150 and miR-92 are also significantly deregulated in patients with CLL. In addition, we detected a marked miR-15a and miR-16 decrease in about 11% of cases. Finally, we identified a set of miRNAs whose expression correlates with biologic parameters of prognostic relevance, particularly with the mutational status of the IgV(H) genes. In summary, the results of this study offer for the first time a comprehensive and quantitative profile of miRNA expression in CLL and their healthy counterpart, suggesting that miRNAs could play a primary role in the disease itself.

Abstract: GPR37 is an orphan G protein-coupled receptor expressed in mammalian brain, and its insoluble aggregates are found in the brain samples of juvenile Parkinson's disease patients. We have produced a Gpr37 knock-out mouse strain and identified several phenotypic features that are similar to those reported for mutants of genes encoding components of synaptic dopamine vesicles. Our results reveal an unanticipated role of GPR37 in regulating substantia nigra-striatum dopaminergic signaling. Gpr37(-/-) mice are viable, with normal brain development and anatomy, but they exhibit reduced striatal dopamine content, enhanced amphetamine sensitivity, and specific deficits in motor behavior paradigms sensitive to nigrostriatal dysfunction. These functional alterations are not associated with any substantial loss of substantia nigra neurons or degeneration of striatal dopaminergic afferences, the main histological marks of Parkinson's disease. The inactivation of GPR37, in fact, has protective effects on substantia nigra neurons, causing resistance to treatment with the Parkinsonian neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.

Abstract: The Neurospora crassa blind mutant white collar-1 (wc-1) is pleiotropically defective in all blue light-induced phenomena, establishing a role for the wc-1 gene product in the signal transduction pathway. We report the cloning of the wc-1 gene isolated by chromosome walking and mutant complementation. The elucidation of the wc-1 gene product provides a key piece of the blue light signal transduction puzzle. The wc-1 gene encodes a 125 kDa protein whose encoded motifs include a single class four, zinc finger DNA binding domain and a glutamine-rich putative transcription activation domain. We demonstrate that the wc-1 zinc finger domain, expressed in Escherichia coli, is able to bind specifically to the promoter of a blue light-regulated gene of Neurospora using an in vitro gel retardation assay. Furthermore, we show that wc-1 gene expression is autoregulated and is transcriptionally induced by blue light irradiation.

Abstract: The rolA gene encoded on the Ri plasmid A4 of Agrobacterium rhizogenes is one of the transferred (TL-DNA) genes involved in the pathogenesis of hairy-root disease in plants. The function of the 100-amino acid protein product of rolA is unknown, although its expression causes physiological and developmental alterations in transgenic plants. The rolA gene of A. rhizogenes contains an intron in its untranslated leader region that has features typical of plant pre-messenger RNA introns. Transcription and splicing of the rolA pre-messenger RNA occur in the plant cell.