Biology subjects

Moss, W. N.

Publications and source records attributed to Moss, W. N..

6 recordsLinked to original sources

bioRxiv2024

A common set of structurally distinct endogenous retroviruses predict survival in multiple human tumor types

Accumulating evidence suggests that viral mimicry induction in cancer cells through the expression of human endogenous retroviral elements (ERVs) enhances tumor immunogenicity and improves response to immunotherapy. However, the characterization of ERV expression across multiple tumor types, their clinical relevance, and their role in tumor immunity remain limited. Here, we assessed the prognostic and immune-related consequences of ERV expression across 8 different tumor types from The Cancer Genome Atlas (TCGA). We applied a recently developed tool, Telescope, to quantify the expression of 14,968 ERVs in bulk tumor RNA-sequencing data. Approximately 15-22% of Telescopes ERVs (navg = 2,736) were expressed in each tumor cohort. We identified both tissue-specific and commonly expressed ERVs across cohorts. Over 50% of tissue-specific ERVs were ubiquitously expressed (n = 1,709) across all 8 tumor types. Using patient clinical data, we identified a subset of 94 ERVs whose expression levels were significantly associated with overall survival, of which 42 were favorably prognostic. Prognostic ERVs displayed unique structural characteristics, including more frequent inverted repeats and more stable secondary structures. Patients were classified based on ERV expression, allowing identification of patient cohorts with greater than 6-fold differences in overall survival. We also found that expression of positively prognostic ERVs was associated with enrichment for selected anti-tumor immune response gene expression signatures. This analysis extends previous results identifying patterns of ERV expression in bulk tumor RNA-seq datasets, providing further insight into the role of ERVs in tumor clinicopathology and immunogenicity.

cancer biology↗

bioRxiv2020

An in silico map of the SARS-CoV-2 RNA Structurome

SARS-CoV-2 is a positive-sense single-stranded RNA virus that has exploded throughout the global human population. This pandemic coronavirus strain has taken scientists and public health researchers by surprise and knowledge of its basic biology (e.g. structure/function relationships in its genomic, messenger and template RNAs) and modes for therapeutic intervention lag behind that of other human pathogens. In this report we used a recently-developed bioinformatics approach, ScanFold, to deduce the RNA structural landscape of the SARS-CoV-2 transcriptome. We recapitulate known elements of RNA structure and provide a model for the folding of an essential frameshift signal. Our results find that the SARS-CoV-2 is greatly enriched in unusually stable and likely evolutionarily ordered RNA structure, which provides a huge reservoir of potential drug targets for RNA-binding small molecules. Our results also predict regions that are accessible for intermolecular interactions, which can aid in the design of antisense therapeutics. All results are made available via a public database (the RNAStructuromeDB) where they may hopefully drive drug discovery efforts to inhibit SARS-CoV-2 pathogenesis.

bioinformatics↗

bioRxiv2019

The RNA encoding the microtubule-associated protein tau has extensive structure that affects its biology

Tauopathies are neurodegenerative diseases that affect millions of people worldwide including those with Alzheimers disease. While many efforts have focused on understanding the role of tau protein in neurodegeneration, there has been little done to systematically analyze and study the structures within taus encoding RNA and their connection to disease pathology. Knowledge of RNA structure can provide insights into disease mechanisms and how to affect protein production for therapeutic benefit. Using computational methods based on thermodynamic stability and evolutionary conservation, we identified structures throughout the tau pre-mRNA, especially at exon-intron junctions and within the 5' and 3' untranslated regions (UTRs). In particular, structures were identified at twenty exon-intron junctions. The 5' UTR contains one structured region, which lies within a known internal ribosome entry site. The 3' UTR contains eight structured regions, including one that contains a polyadenylation signal. A series of functional experiments were carried out to assess the effects of mutations associated with mis-regulation of alternative splicing of exon 10 and to identify regions of the 3' UTR that contain cis-regulatory elements. These studies defined novel structural regions within the mRNA that affect stability and pre-mRNA splicing and may lead to new therapeutic targets for treating tau-associated diseases.

bioinformatics↗

bioRxiv2019

Scans of the MYC mRNA reveal multiple stable secondary structures—including a 3′ UTR motif, conserved across vertebrates, that can affect gene expression.

The MYC gene encodes a human transcription factor and proto-oncogene that is dysregulated in over half of all known cancers. To better understand potential post-transcriptional regulatory features affecting MYC expression, we analyzed secondary structure in the MYC mRNA using a program that is optimized for finding small locally-folded motifs with a high propensity for function. This was accomplished by calculating folding metrics across the MYC sequence using a sliding analysis window and generating unique consensus base pairing models weighted by their lower-than-random predicted folding energy. A series of 30 motifs were identified, primarily in the 5 and 3 untranslated regions, which show evidence of structural conservation and compensating mutations across vertebrate MYC homologs. This analysis was able to recapitulate known elements found within an internal ribosomal entry site, as well as discover a novel element in the 3 UTR that is unusually stable and conserved. This novel motif was shown to affect MYC expression: likely via modulation of miRNA target accessibility. In addition to providing basic insights into mechanisms that regulate MYC expression, this study provides numerous, potentially druggable RNA targets for the MYC gene, which is considered "undruggable" at the protein level.

bioinformatics↗

bioRxiv2018

PolyA tracks and poly-lysine repeats are the Achilles heel of Plasmodium falciparum

Plasmodium falciparum, the causative agent of human malaria, is an apicomplexan parasite with a complex, multi-host life cycle. Sixty percent of transcripts from its extreme AT-rich (81%) genome possess coding polyadenosine (polyA) runs, distinguishing the parasite from its hosts and other sequenced organisms. Recent studies indicate that transcripts with polyA runs encoding poly-lysine are hot spots for ribosome stalling and frameshifting, eliciting mRNA surveillance pathways and attenuating protein synthesis in the majority of prokaryotic and eukaryotic organisms. Here, we show that the P. falciparum translational machinery is paradigm-breaking. Using bioinformatic and biochemical approaches, we demonstrate that both endogenous genes and reporter sequences containing long polyA runs are efficiently and accurately transcribed and translated in P. falciparum cells. Translation of polyA tracks in the parasite does not elicit any response from mRNA surveillance pathways usually seen in host human cells or organisms with similar AT content. The translation efficiency and accuracy of the parasite protein synthesis machinery reveals a unique role of ribosomes in the evolution and adaptation of P. falciparum to an AU-rich transcriptome and polybasic amino sequences. Finally, we show that the ability of P. falciparum to synthesize long poly-lysine repeats has given this parasite a unique protein exportome and an advantage in infectivity that can be suppressed by addition of exogenous poly-basic polymers.

microbiology↗

bioRxiv2018

Analysis of a structured intronic region of the LMP2 pre-mRNA from EBV reveals associations with human regulatory proteins.

Objective: The pre-mRNA of the Epstein-Barr virus LMP2 (latent membrane protein 2) has a region of unusual RNA structure that partially spans two consecutive exons and the entire intervening intron; suggesting RNA folding might affect splicing--particularly via interactions with human regulatory proteins. To better understand the roles of protein associations with this structured intronic region, we undertook a combined bioinformatics (motif searching) and experimental analysis (biotin pulldowns and RNA immunoprecipitations) of protein binding. Result: Characterization of the ribonucleoprotein composition of this region revealed several human proteins as interactors: regulatory proteins hnRNP A1 (heterogeneous nuclear ribonucleoprotein A1), hnRNP U, HuR (human antigen R), and PSF (polypyrimidine tract-binding protein-associated splicing factor), as well as, unexpectedly, the cytoskeletal protein actin. Treatment of EBV-infected cells with drugs that alter actin polymerization specifically showed marked effects on splicing in this region. This suggests a potentially novel role for nuclear actin in regulation of viral RNA splicing.

molecular biology↗