While post-transcriptional control is thought to be required at the periphery of neurons and glia, its extent is unclear. Here, we investigate systematically the spatial distribution and expression of mRNA at single molecule sensitivity and their corresponding proteins of 200 YFP trap lines across the intact Drosophila nervous system. 97.
View Article and Find Full Text PDFThe level of each RNA species depends on the balance between its rates of production and decay. Although previous studies have measured RNA decay across the genome in tissue culture and single-celled organisms, few experiments have been performed in intact complex tissues and organs. It is therefore unclear whether the determinants of RNA decay found in cultured cells are preserved in an intact tissue, and whether they differ between neighboring cell types and are regulated during development.
View Article and Find Full Text PDFDespite an unprecedented global research effort on SARS-CoV-2, early replication events remain poorly understood. Given the clinical importance of emergent viral variants with increased transmission, there is an urgent need to understand the early stages of viral replication and transcription. We used single-molecule fluorescence in situ hybridisation (smFISH) to quantify positive sense RNA genomes with 95% detection efficiency, while simultaneously visualising negative sense genomes, subgenomic RNAs, and viral proteins.
View Article and Find Full Text PDFType I toxin-antitoxin (TA) systems typically consist of a protein toxin that imbeds in the inner membrane where it can oligomerize and form pores that change membrane permeability, and an RNA antitoxin that interacts directly with toxin mRNA to inhibit its translation. In Escherichia coli, symE/symR is annotated as a type I TA system with a non-canonical toxin. SymE was initially suggested to be an endoribonuclease, but has predicted structural similarity to DNA binding proteins.
View Article and Find Full Text PDFThe measurement of RNA abundance derived from massively parallel sequencing experiments is an essential technique. Methods that reduce ribosomal RNA levels are usually required prior to sequencing library construction because ribosomal RNA typically comprises the vast majority of a total RNA sample. For some experiments, ribosomal RNA depletion is favored over poly(A) selection because it offers a more inclusive representation of the transcriptome.
View Article and Find Full Text PDFFollowing re-sequencing of the miSFIT constructs used in the paper, two of the construct variants inserted into the 3'UTR of PD-1, namely '12C' and '17A, 18G', have been found to contain additional insertions not present in the other construct variants. The data points corresponding to these constructs in Figs. 2c, f and Supplementary Fig.
View Article and Find Full Text PDFPrecise, analogue regulation of gene expression is critical for cellular function in mammals. In contrast, widely employed experimental and therapeutic approaches such as knock-in/out strategies are more suitable for binary control of gene activity. Here we report on a method for precise control of gene expression levels in mammalian cells using engineered microRNA response elements (MREs).
View Article and Find Full Text PDFMost eukaryotic mRNAs are recruited to the ribosome by recognition of a 5' mGpppN cap. 30 years of genetic and biochemical evidence point to a role for interaction between the 5' cap-interacting factors and the 3' poly(A)-binding protein in bringing the ends of the mRNA into close proximity and promoting both translation and stability of the mRNA, in a form known as the "closed loop". However, the results of recent RNA-protein interaction studies suggest that not all mRNAs have equal access to the closed loop factors.
View Article and Find Full Text PDFThe translation initiation factor eIF3 is a multi-subunit protein complex that coordinates the assembly of the 43S pre-initiation complex in eukaryotes. Prior studies have demonstrated that not all subunits of eIF3 are essential for the initiation of translation, suggesting that some subunits may serve regulatory roles. Here, we show that loss-of-function mutations in the genes encoding the conserved eIF3k and eIF3l subunits of the translation initiation complex eIF3 result in a 40% extension in lifespan and enhanced resistance to endoplasmic reticulum (ER) stress in Caenorhabditis elegans.
View Article and Find Full Text PDFTranslation is a core cellular process carried out by a highly conserved macromolecular machine, the ribosome. There has been remarkable evolutionary adaptation of this machine through the addition of eukaryote-specific ribosomal proteins whose individual effects on ribosome function are largely unknown. Here we show that eukaryote-specific Asc1/RACK1 is required for efficient translation of mRNAs with short open reading frames that show greater than average translational efficiency in diverse eukaryotes.
View Article and Find Full Text PDFAntibodies made in large animals are integral to many biomedical research endeavors. Domesticated herd animals like goats, sheep, donkeys, horses and camelids all offer distinct advantages in antibody production. However, their cost of use is often prohibitive, especially where poor antigen response is commonplace; choosing a non-responsive animal can set a research program back or even prevent experiments from moving forward entirely.
View Article and Find Full Text PDFIt remains particularly problematic to define the structures of native macromolecular assemblies, which are often of low abundance. Here we present a strategy for isolating complexes at endogenous levels from GFP-tagged transgenic cell lines. Using cross-linking mass spectrometry, we extracted distance restraints that allowed us to model the complexes' molecular architectures.
View Article and Find Full Text PDFIn addition to its high affinity for antibody Fc domains, staphylococcal Protein A has been shown to bind certain Fab domains. We investigated this in order to develop a small, recombinant Protein A-binding alternative to immunoglobulin G (IgG) from nanobodies, single-domain antibodies derived from a camelid variant IgG's variable region. We engineered a nanobody with affinity solely for Protein A as well as a dimerized version of higher affinity for typical multidomain Protein A constructs.
View Article and Find Full Text PDFNanobodies are single-domain antibodies derived from the variable regions of Camelidae atypical immunoglobulins. They show promise as high-affinity reagents for research, diagnostics and therapeutics owing to their high specificity, small size (∼15 kDa) and straightforward bacterial expression. However, identification of repertoires with sufficiently high affinity has proven time consuming and difficult, hampering nanobody implementation.
View Article and Find Full Text PDFPurpose: In order to develop a theoretical framework for person-centered care models for children with epilepsy and their parents, we conducted a qualitative study to explore and understand parents' needs, values, and preferences to ultimately reduce barriers that may be impeding parents from accessing and obtaining help for their children's co-occurring problems.
Methods: A qualitative grounded theory study design was utilized to understand parents' perspectives. The participants were 22 parents of children with epilepsy whose age ranged from 31 to 53 years.
Cellular differentiation is driven by coordinately regulated changes in gene expression. Recent discoveries suggest that translation contributes as much as transcription to regulating protein abundance, but the role of translational regulation in cellular differentiation is largely unexplored. Here we investigate translational reprogramming in yeast during cellular adaptation to the absence of glucose, a stimulus that induces invasive filamentous differentiation.
View Article and Find Full Text PDFFinite element (FE) modeling of rough surfaces is becoming increasingly common. However, the quality of the assumptions being made in these models, and thus the quality of the models themselves, is often unclear. Decisions about the geometry of the surface to be modeled, including the size of the surface to be modeled, the lateral resolution of the measured surface data to be used, and the formulation of the probabilistic surface to be used, can have a significant effect on a model's behavior.
View Article and Find Full Text PDFThis work discusses some of the benefits, techniques, challenges, and considerations associated with the incorporation of measured surfaces in finite element (FE) models including how much surface data to measure and import into the model, the shape of the surface geometry to create, the presence and effect of surface layers and impurities, the required mesh density for rough surfaces, the nature of the element formulations and material properties at small length scales, the differences between measurement and FE coordinate systems, the limitations and idealizations of the FE method, issues associated with boundary conditions and their ability to impose or prevent conformal contact, and issues associated with the size of the pinball region and the contact stiffness relative to the nature of the surface. It also describes some current and future research directions that can be used to validate and expand existing techniques and to improve our understanding of surface phenomena.
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