169,825 research outputs found
ELAV proteins along evolution : back to the nucleus?
No full textThe complex interplay of post-transcriptional regulatory mechanisms mediated by RNA-binding proteins (RBP) at different steps of RNA metabolism is pivotal for the development of the nervous system and the maintenance of adult brain activities. In this review, we will focus on the highly conserved ELAV gene family encoding for neuronal-specific RBPs which are necessary for proper neuronal differentiation and important for synaptic plasticity process. In the evolution from Drosophila to man, ELAV proteins seem to have changed their biological functions in relation to their different subcellular localization. While in Drosophila, they are localized in the nuclear compartment of neuronal cells and regulate splicing and polyadenylation, in mammals, the neuronal ELAV proteins are mainly present in the cytoplasm where they participate in regulating mRNA target stability, translation and transport into neurites. However, recent data indicate that the mammalian ELAV RBPs also have nuclear activities, similarly to their fly counterpart, being them able to continuously shuttle between the cytoplasm and the nucleus. Here, we will review and comment on all the biological functions associated with neuronal ELAV proteins along evolution and will show that the post-transcriptional regulatory network mediated by these RBPs in the brain is highly complex and only at an initial stage of being fully understood. This article is part of a Special Issue entitled 'RNA and splicing regulation in neurodegeneration'
Post-transcriptional regulation mediated by ELAV/Hu RNA-binding proteins in motor neuron-like NSC34 cells
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Identification of new ANG gene mutations in a large cohort of Italian patients with Amyotrophic Lateral Sclerosis
No full textAngiogenin (ANG) gene, coding for an angiogenic factor up-regulated by hypoxia and expressed in ventral horn motor neurons, is a novel candidate for the pathogenesis of amyotrophic lateral sclerosis (ALS). ALS is a fatal neurodegenerative disease characterized by the selective loss of cortical and spinal motor neurons. Missense mutations in ANG gene have been identified in two ALS populations from Northern Europe and North America, both in familial (FALS) and sporadic (SALS) patients, but they do not seem to be frequent in the Italian population. We performed a mutational screening in a large cohort of 737 Italian ALS patients, including 605 SALS and 132 FALS cases. We identified seven different mutations, five of which are novel, in nine patients (six SALS and three FALS), but not in 515 healthy controls. Three mutations are located in the signal peptide region, three in the coding sequence, and one in the 3′ untranslated region. In our ALS population, the observed mutational frequency of ANG gene accounts for about 1.2%, with an overrepresentation of FALS (2.3%) compared to SALS (1%) cases. We also found the previously described I46V substitution in six patients and four controls, suggesting that this mutation may represent a benign variant, at least in the Italian population. Our results provide further evidence of a tight link between angiogenesis and ALS pathogenesis and suggest that mutations in ANG gene are associated with an increased risk to develop ALS
TDP-43 is recruited to stress granules in conditions of oxidative insult
No full textTAR DNA-binding protein 43 (TDP-43) forms abnormal ubiquitinated and phosphorylated inclusions in brain tissues from patients with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration. TDP-43 is a DNA/RNA-binding protein involved in RNA processing, such as transcription, pre-mRNA splicing, mRNA stabilization and transport to dendrites. We found that in response to oxidative stress and to environmental insults of different types TDP-43 is capable to assemble into stress granules (SGs), ribonucleoprotein complexes where protein synthesis is temporarily arrested. We demonstrated that a specific aminoacidic interval (216-315) in the C-terminal region and the RNA-recognition motif 1 domain are both implicated in TDP-43 participation in SGs since their deletion prevented the recruitment of TDP-43 into SGs. Our data show that TDP-43 is a specific component of SGs and not of processing bodies, although we proved that TDP-43 is not necessary for SG formation, and its gene silencing does not impair cell survival during stress. The analysis of spinal cord tissue from ALS patients showed that SG markers are not entrapped in TDP-43 pathological inclusions. Although SGs were not evident in ALS brains, we speculate that an altered control of mRNA translation in stressful conditions may trigger motor neuron degeneration at early stages of the disease
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