Computational Biology Commons^™

Mitochondrial Trna-Derived Fragments As Candidate Metastasis-Modifying Rna, Katy L. Swancutt, R. Mckinnon Walsh, Sydney Quijano, Emily Schueddig, Devin C. Koestler, Adam D. Scheid, Tony Vanden Bush, Yi Jing, Isidore Rigoutsos, Danny R. Welch

Computational Medicine Center Faculty Papers

UNLABELLED: How mitochondrial DNA (mtDNA) polymorphisms influence complex phenotypes remains poorly understood. Using mitochondrial-nuclear exchange mice, we previously showed that mtDNA single-nucleotide polymorphisms (SNP) modify metastasis, cardiovascular disease, and epigenetic marks independently of metabolic differences. The only mtDNA SNP correlating with these phenotypes resides in the gene encoding mitochondrial transfer RNA (tRNA)-arginine [mt-tRNAArg (UCG), mt-TR], suggesting a role for non-protein-coding loci. In this study, we identify and preliminarily characterize previously undescribed tRNA-derived fragments (tRF) generated from mt-TRs. Northern blotting revealed distinct tRF that are differentially expressed among mtDNA SNPs, between lung and liver, and between sexes. Surprisingly, small RNA sequencing …

Integrative Rna-Seq Analysis Reveals Stress Type-Dependent Lncrna-Centered Co-Expression Networks Across Human Cellular Stress Contexts, Christina Anastasiadi, Aggeliki Kasapi, Ioannis Sentementes, Vasileios Gouzouasis, Margaritis Tsifintaris, Antonis Giannakakis

Computational Medicine Center Faculty Papers

Long non-coding RNAs (lncRNAs) are emerging as important regulators of cellular adaptation to environmental and molecular stress, but the extent to which their responses remain reproducible and stress-type-dependent across human stress conditions remains unclear. Here, we performed an integrative transcriptomic meta-analysis of human stress-response datasets from ASTRA and GEO, focusing on normal, non-cancerous, wild-type human cell lines exposed to oxidative stress (H2O2), hypoxia, heat stress, or UV-induced DNA damage. Gene Ontology (GO) enrichment analysis of differentially expressed (DE) protein-coding mRNAs confirmed that the resulting stress-stratified comparison captured biologically coherent transcriptional programmes to oxidative stress signaling, hypoxic and metabolic adaptation, heat-induced …

Organism-Specific Sequence Motifs Link Ribosomal Rnas To Brain Disorders, Isidore Rigoutsos, Stepan Nersisyan, Eric Londin, Iliza Nazeraj, Bonnie Dong, Anastasios Vourekas, Phillipe Loher

Computational Medicine Center Faculty Papers

We report that in humans, mice, fruit flies, and worms, the ribosomal RNAs and the transcribed spacers of 45S are densely packed with organism-specific sequence motifs that are primarily shared with nervous system genes. The human ribosomal RNAs and 45S spacers contain 1,723 such motifs. Specific combinations of these motifs are predominantly found in 3,430 human nervous system genes, of which 1,046 are genes associated with brain disorders, including autism spectrum disorder and schizophrenia. The sequences of the 1,723 motifs and their locations in the introns and exons of nervous system genes are unique to primates. Experimental evidence indicates that …

The Role Of Secondary And Tertiary Structure In The Cap-Independent Translation Of Fgf-9 And Hif-1-Alpha, Amanda Michelle Whittaker

Dissertations, Theses, and Capstone Projects

Under normoxic conditions, eukaryotes initiate translation of RNA through eIF4E recognition of the 5’ cap. However, under cellular stress, eukaryotic translation must be initiated through a 4E-independent, or “cap-independent” mechanism, involving eukaryotic initiation factor 4G (eIF4G) binding directly to the 5’ untranslated regions (5’ UTR) of the RNA. eIF4G binding then recruits the ribosome to the transcript. While this mechanism is useful for translation of apoptotic transcripts and transcripts involved in cell survival, cap-independent translation is also utilized by oncogenic RNA for tumorigenesis. Previous work by our lab and others has categorized this recruitment and initiation mechanism as either internal-ribosome-entry-site …

The Trnaval Half: A Strong Endogenous Toll-Like Receptor 7 Ligand With A 5′-Terminal Universal Sequence Signature, Kamlesh Ganesh Pawar, Takuya Kawamura, Yohei Kirino

Computational Medicine Center Faculty Papers

Toll-like receptors (TLRs) are crucial components of the innate immune system. Endosomal TLR7 recognizes single-stranded RNAs, yet its endogenous ssRNA ligands are not fully understood. We previously showed that extracellular (ex-) 5'-half molecules of tRNA^HisGUG (the 5'-tRNA^HisGUG half) in extracellular vesicles (EVs) of human macrophages activate TLR7 when delivered into endosomes of recipient macrophages. Here, we fully explored immunostimulatory ex-5'-tRNA half molecules and identified the 5'-tRNA^ValCAC/AAC half, the most abundant tRNA-derived RNA in macrophage EVs, as another 5'-tRNA half molecule with strong TLR7 activation capacity. Levels of the ex-5'-tRNA^ValCAC/AAC half were highly up-regulated in macrophage EVs …

Annotation Of Non-Model Species’ Genomes, Taiya Jarva

Master's Theses

The innovations in high throughput sequencing technologies in recent decades has allowed unprecedented examination and characterization of the genetic make-up of both model and non-model species, which has led to a surge in the use of genomics in fields which were previously considered unfeasible. These advances have greatly expanded the realm of possibilities in the fields of ecology and conservation. It is now possible to the identification of large cohorts of genetic markers, including single nucleotide polymorphisms (SNPs) and larger structural variants, as well as signatures of selection and local adaptation. Markers can be used to identify species, define population …

Adjusting For Gene-Specific Covariates To Improve Rna-Seq Analysis, Hyeongseon Jeon, Kyu-Sang Lim, Yet Nguyen, Dan Nettleton

Mathematics & Statistics Faculty Publications

Summary

This paper suggests a novel positive false discovery rate (pFDR) controlling method for testing gene-specific hypotheses using a gene-specific covariate variable, such as gene length. We suppose the null probability depends on the covariate variable. In this context, we propose a rejection rule that accounts for heterogeneity among tests by employing two distinct types of null probabilities. We establish a pFDR estimator for a given rejection rule by following Storey's q-value framework. A condition on a type 1 error posterior probability is provided that equivalently characterizes our rejection rule. We also present a suitable procedure for selecting a tuning …

Characterization Of The Growth Factor Receptor Network Oncogenes In Lung Cancer, Ashley Duche

Pharmaceutical Sciences (MS) Theses

Lung cancer remains the leading cause of cancer related deaths worldwide, reportedly contributing to 1.8 million of the 10.0 million mortalities documented in the year 2020. Although advancements have been made in therapeutics and diagnostic methods, formulation of effective treatments and development of drug resistance continues to be a challenge. These challenges arise from our lack of understanding of intricate signaling pathways, such as the Growth Factor Receptor Network (GFRN), which contributes to complex lung tumor heterogeneity allowing for drug resistance development. In this study, gene expression signatures of six GFRN oncogenes overexpressed in human mammary epithelial cells (HMECs) were …

Rnase Κ Promotes Robust Pirna Production By Generating 2',3'-Cyclic Phosphate-Containing Precursors, Megumi Shigematsu, Takuya Kawamura, Keisuke Morichika, Natsuko Izumi, Takashi Kiuchi, Shozo Honda, Venetia Pliatsika, Ryuma Matsubara, Isidore Rigoutsos, Susumu Katsuma, Yukihide Tomari, Yohei Kirino

Computational Medicine Center Faculty Papers

In animal germlines, PIWI proteins and the associated PIWI-interacting RNAs (piRNAs) protect genome integrity by silencing transposons. Here we report the extensive sequence and quantitative correlations between 2′,3′-cyclic phosphate-containing RNAs (cP-RNAs), identified using cP-RNA-seq, and piRNAs in the Bombyx germ cell line and mouse testes. The cP-RNAs containing 5′-phosphate (P-cP-RNAs) identified by P-cP-RNA-seq harbor highly consistent 5′-end positions as the piRNAs and are loaded onto PIWI protein, suggesting their direct utilization as piRNA precursors. We identified Bombyx RNase Kappa (BmRNase κ) as a mitochondria-associated endoribonuclease which produces cP-RNAs during piRNA biogenesis. BmRNase κ-depletion elevated transposon levels and disrupted a piRNA-mediated …

Characteristics And Prediction Of Rna Structure., Hengwu Li, Daming Zhu, Caiming Zhang, Huijian Han, Keith A Crandall

Computational Biology Institute

RNA secondary structures with pseudoknots are often predicted by minimizing free energy, which is NP-hard. Most RNAs fold during transcription from DNA into RNA through a hierarchical pathway wherein secondary structures form prior to tertiary structures. Real RNA secondary structures often have local instead of global optimization because of kinetic reasons. The performance of RNA structure prediction may be improved by considering dynamic and hierarchical folding mechanisms. This study is a novel report on RNA folding that accords with the golden mean characteristic based on the statistical analysis of the real RNA secondary structures of all 480 sequences from RNA …