Project description:Alternative splicing (AS) of pre-mRNA is utilized by higher eukaryotes to achieve increased transcriptome and proteomic complexity. The serine/arginine (SR) splicing factors regulate tissue- or cell type-specific AS in a concentration and phosphorylation dependent manner. However, the mechanisms that modulate the cellular levels of active SR proteins remain to be elucidated. In the present study, we provide evidence for a role for the long nuclear-retained regulatory RNA (nrRNA), MALAT1 in AS regulation. MALAT1 interacts with SR proteins and influences the distribution of these and other splicing factors in nuclear speckle domains. Depletion of MALAT1 changes AS of endogenous pre-mRNAs, similar to what was observed upon overexpression of SR proteins. Furthermore, MALAT1 regulates cellular levels of phosphorylated forms of SR proteins. Taken together, our results suggest that MALAT1 regulates AS by modulating the levels of active SR proteins. Our results further highlight a novel role for a nrRNA in the regulation of gene expression. Malat1 Antisense and control knockdowns evaluated on a microarray platform to profile alternative splicing levels for 5782 cassette-type alternative exons.
Project description:Alternative splicing (AS) of pre-mRNA is utilized by higher eukaryotes to achieve increased transcriptome and proteomic complexity. The serine/arginine (SR) splicing factors regulate tissue- or cell type-specific AS in a concentration and phosphorylation dependent manner. However, the mechanisms that modulate the cellular levels of active SR proteins remain to be elucidated. In the present study, we provide evidence for a role for the long nuclear-retained regulatory RNA (nrRNA), MALAT1 in AS regulation. MALAT1 interacts with SR proteins and influences the distribution of these and other splicing factors in nuclear speckle domains. Depletion of MALAT1 changes AS of endogenous pre-mRNAs, similar to what was observed upon overexpression of SR proteins. Furthermore, MALAT1 regulates cellular levels of phosphorylated forms of SR proteins. Taken together, our results suggest that MALAT1 regulates AS by modulating the levels of active SR proteins. Our results further highlight a novel role for a nrRNA in the regulation of gene expression.
Project description:In this study, we investigated the effects of HSV-1 infection on tau phosphorylation in human brain cortical organoids. Our findings demonstrate that HSV-1 triggers nuclear accumulation of phosphorylated tau in neurons within the developing cortical plate as well as in neural precursor cells (NPCs) in the ventricular/subventricular-like zones of these differentiating cortical structures. Antiviral treatment effectively inhibited nuclear tau accumulation in both KOS- and 17syn+-infected organoids. Importantly, for the first time we provide evidence of a potential interaction of phosphorylated tau with HSV-1 genome. Furthermore, we ruled out the involvement of the Cyclin-dependent kinase 5 (Cdk5) in the nuclear phosphorylation of tau. Finally, we show that HSV-1 causes a significant alteration in the abundance of components of nuclear speckles and proteins known to be associated with neurodegenerative diseases.