The endoplasmic reticulum (ER) coordinates mRNA translation and processing of secreted and endomembrane proteins. ER-associated degradation (ERAD) prevents the accumulation of misfolded proteins in the ER, but the physiological regulation of this process remains poorly characterized. Here, in a genetic screen using an ERAD model substrate in Caenorhabditis elegans, we identified an anti-viral RNA interference pathway, referred to as ER-associated RNA silencing (ERAS), which acts together with ERAD to preserve ER homeostasis and function.
View Article and Find Full Text PDFTissue homeostasis requires maintenance of functional integrity under stress. A central source of stress is mechanical force that acts on cells, their nuclei, and chromatin, but how the genome is protected against mechanical stress is unclear. We show that mechanical stretch deforms the nucleus, which cells initially counteract via a calcium-dependent nuclear softening driven by loss of H3K9me3-marked heterochromatin.
View Article and Find Full Text PDFCytoscape is one of the most successful network biology analysis and visualization tools, but because of its interactive nature, its role in creating reproducible, scalable, and novel workflows has been limited. We describe Cytoscape Automation (CA), which marries Cytoscape to highly productive workflow systems, for example, Python/R in Jupyter/RStudio. We expose over 270 Cytoscape core functions and 34 Cytoscape apps as REST-callable functions with standardized JSON interfaces backed by Swagger documentation.
View Article and Find Full Text PDFDuring the last decade, the study of mRNA decay has largely benefited from an increasing number of high-throughput assays that emerged from developments in next generation sequencing (NGS) technologies as well as mass spectrometry. While assay-specific data analysis is often reported and software made available many researchers struggle with the overwhelming challenge of integrating data from diverse assays, different sources, and of different formats.We here use Python, R, and bash to analyze and integrate RNAseq and eCLIP data publicly available from ENCODE.
View Article and Find Full Text PDFGrowing evidence suggests a key role for RNA binding proteins (RBPs) in genome stability programs. Additionally, recent developments in RNA sequencing technologies, as well as mass-spectrometry techniques, have greatly expanded our knowledge on protein-RNA interactions. We here use full transcriptome sequencing and label-free LC/MS/MS to identify global changes in protein-RNA interactions in response to etoposide-induced genotoxic stress.
View Article and Find Full Text PDFUnlabelled: Survival of chronic lymphocytic leukemia (CLL) cells depends on stimuli provided by a suitable microenvironment. The factors and mechanisms providing this growth support for CLL cells are not fully understood. We found that plasma levels of macrophage migration inhibitory factor (MIF), a proinflammatory and immunoregulatory chemokine, were elevated in CLL patients.
View Article and Find Full Text PDFIn response to DNA damage, cells activate a complex, kinase-based signaling network to arrest the cell cycle and allow time for DNA repair, or, if the extend of damage is beyond repair capacity, induce apoptosis. This signaling network, which is collectively referred to as the DNA damage response (DDR), is primarily thought to consist of two components-a rapid phosphorylation-driven signaling cascade that results in immediate inhibition of Cdk/cyclin complexes and a delayed transcriptional response that promotes a prolonged cell cycle arrest through the induction of Cdk inhibitors, such as p21. In recent years a third layer of complexity has emerged that involves potent posttranscriptional regulatory mechanisms that control the cellular response to DNA damage.
View Article and Find Full Text PDFRecent therapeutic advances in chronic lymphocytic leukemia (CLL) are reflected by high response rates in most subsets of patients. However, refractory disease remains a problem, and virtually all of even the most sensitive tumors eventually recur. Therefore, ongoing efforts aim at the development of optimized interventional designs that more specifically target the strong pro-survival signature of the transformed B cell.
View Article and Find Full Text PDFBackground: Genetic modification of capsid proteins by peptide insertion has created the possibility of using adeno-associated viral (AAV) vectors for receptor specific gene transfer (AAV targeting). The most common site used for insertion in AAV serotype 2 capsids are amino acid positions 587 and 588 located at the second highest capsid protrusion. Reasoning that peptide insertions at the most exposed position augments target receptor interaction, we explored position 453 as a new insertion site.
View Article and Find Full Text PDFAdeno-associated virus type 2 (AAV-2) targeting vectors have been generated by insertion of ligand peptides into the viral capsid at amino acid position 587. This procedure ablates binding of heparan sulfate proteoglycan (HSPG), AAV-2's primary receptor, in some but not all mutants. Using an AAV-2 display library, we investigated molecular mechanisms responsible for this phenotype, demonstrating that peptides containing a net negative charge are prone to confer an HSPG nonbinding phenotype.
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