Search bioRxiv⌕ Search

bioRxiv · 10.1101/2023.10.24.563766

Roles of SNORD115 and SNORD116 ncRNA clusters in neuronal differentiation

Abstract

Prader-Willi syndrome shows features linked to brain development and hypothalamus-related endocrine abnormalities. The smallest clinical deletions fall within the large ([~]650Kb) SNHG14 gene, removing 29 consecutive introns that each generate SNORD116. SNHG14 also includes 48 tandem introns encoding SNORD115 and generates multiple, extended snoRNA-related species. SNORD115 and SNORD116 resemble box C/D small nucleolar RNAs (snoRNAs) but lack known targets. Both snoRNAs strongly accumulated during neuronal differentiation. SNORD116 accumulation apparently reflected stabilization, potentially linked to the appearance of FBLL1, a homologue of the ubiquitous snoRNA-associated protein Fibrillarin (FBL). In contrast, SNORD115 was selectively transcribed, apparently due to regulated termination. For functional characterization we created cell lines lacking only the expressed, paternal, SNORD115 or SNORD116 cluster. Analyses during neuronal development indicated changes in RNA stability and protein synthesis. Altered mRNAs included MAGEL2, mutation of which causes the PWS-like disorder Schaaf-Yang syndrome. Comparison of SNORD115 and SNORD116 mutants indicated overlapping or interacting functions. Most changes in mRNA and protein abundance appeared relatively late in development, with roles including cytoskeleton formation, extracellular matrix, neuronal arborization. Comparison with human embryonic midbrain development suggested enhanced progression in neuronal development in the snoRNA mutants. Subtle impairment of relative neuronal maturation during development, might generate the clinical phenotypes.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Helwak, A., Turowski, T., Spanos, C., Tollervey, D.. 2023-10-24. Roles of SNORD115 and SNORD116 ncRNA clusters in neuronal differentiation. https://doi.org/10.1101/2023.10.24.563766

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

HUH-tag conjugation enables accessible, site-specific functionalization of DNA origami with signaling-competent proteins

DNA origami enables precise nanometer scale control over the number, spacing, and geometry of biomolecules, making it a powerful tool for dissecting spatially organized biological processes such as receptor signaling. However, functionalizing origami with proteins remains a bottleneck restricting the technology to specialized laboratories. Here we show that viral-derived HUH endonuclease tags, small (~10 kDa) domains that form a covalent phosphotyrosine bond with short unmodified ssDNA, provide a simple and cost-effective route to decorating DNA origami with functional proteins. Using interleukin-1{beta} (IL-1{beta}) as a model ligand, we generated recombinant IL-1{beta}-HUH, achieved efficient site-specific conjugation to unmodified ssDNA within minutes, and coupled the conjugates to a DNA origami pegboard with tunable stoichiometry. IL-1{beta}-functionalized origami triggered ligand-dependent signalling in living cells and allowed visualization of the recruitment of downstream signaling molecules, confirming that HUH-tag conjugation preserves functionality. Because this strategy requires only standard molecular biology equipment and unmodified DNA, it lowers a technical and financial barrier to DNA origami-based experimentation, opening the approach to a broader range of biological questions and laboratories outside the DNA nanotechnology field.

cell biology↗

Global mapping of VEGF-A driven changes in the RNA bound phospho-proteome reveals a molecular switch to coordinate angiogenesis in endothelial cells

RNA binding proteins (RBPs) serve as upstream master regulators of cellular fate transitions at the post-transcriptional level. RBP-RNA interactions are dynamically regulated by post-translational modifications to coordinate cellular responses. We hypothesised that changes in RBP phosphorylation will play a key role in coordinating angiogenesis, the formation of new blood vessels, in endothelial cells (ECs). Therefore, we used phospho-proteomic analysis of the mRNA bound proteome to identify global phosphorylation changes in mouse cardiac ECs during acute and prolonged VEGF-A stimulation. Of the differentially phosphorylated RBPs, we found that the phosphorylation of serine 199 within mRNA bound Phf6 (PHD finger protein 6) was consistently increased following VEGF-A stimulation. Phf6 phosphorylation at this specific site was sufficient and required to induce a pro-angiogenic phenotype, facilitating a change in Phf6 conformation promoting interaction with distinct RNAs. We show here that Phf6 phosphorylation at serine 199, downstream of VEGF-A, acts as a molecular switch to differentially coordinate a decrease of anti-angiogenic RNAs (i.e. extracellular matrix genes) and an increase in pro-angiogenesis related RNAs, in part by differentially regulating their stability, to promote angiogenesis.

cell biology↗

Metaplasia Orchestrates Tissue Recovery and Immune Remodeling Through CD73 in Chronic Pancreatitis

Chronic inflammatory injury promotes epithelial metaplasia, and progression from metaplasia to dysplasia is a recognized initiating event in carcinogenesis, as metaplastic cells exhibit heightened susceptibility to genetic alterations. In the pancreas, persistent acinar-to-ductal metaplasia (ADM) can progress to pancreatic intraepithelial neoplasia (PanIN), yet the mechanisms that determine whether ADM resolves or persists with fibrosis and sustained inflammation remain poorly defined. Here, we identify CD73 as a central regulator of ADM fate, tissue repair, and immune microenvironment remodeling during chronic pancreatic injury. Analysis of previously published single-cell RNA sequencing dataset from chronic pancreatitis (CP) tissues identified enrichment of Nt5e, which encodes CD73, within Hnf1{beta} ADM populations. Hnf1bCreERT2 and CD73fl/fl;Hnf1bCreERT2 mice were treated with caerulein for 4 weeks to induce pancreatitis and ADM prior to tamoxifen-induced deletion of CD73 in HNF1B-expressing metaplastic epithelial cells. Histologic phenotyping and immune profiling were performed using immunohistochemistry and imaging mass cytometry. Metaplasia-specific CD73 deletion exacerbated pancreatic injury and fibrosis, impaired epithelial proliferation and recovery of the acinar compartment, and altered the abundance and spatial organization of inflammatory cells. Ex vivo ADM assays further demonstrated that CD73 loss increased ADM formation and the production of MCP-1 and TIMP-1. These findings identify CD73 as a context-dependent checkpoint linking epithelial plasticity and immune modulation during chronic pancreatic injury and tissue repair.

cell biology↗