Proc Natl Acad Sci U S A
August 2024
While the centrality of posttranscriptional modifications to RNA biology has long been acknowledged, the function of the vast majority of modified sites remains to be discovered. Illustrative of this, there is not yet a discrete biological role assigned for one of the most highly conserved modifications, 5-methyluridine at position 54 in tRNAs (mU54). Here, we uncover contributions of mU54 to both tRNA maturation and protein synthesis.
View Article and Find Full Text PDFDirect analysis of ribosome targeting (DART) allows investigators to measure the translation initiation potential of thousands of RNAs in parallel. Here, we describe an optimized protocol for generating active translation extract from S. cerevisiae, followed by in vitro translation, purification of ribosome-bound RNAs, and subsequent library preparation and sequencing.
View Article and Find Full Text PDFQuantitative comparisons of RNA levels from different samples can lead to new biological understanding if they are able to distinguish biological variation from variable sample preparation. These challenges are pronounced in comparisons that require complex biochemical manipulations (e.g.
View Article and Find Full Text PDFTranslational control shapes the proteome in normal and pathophysiological conditions. Current high-throughput approaches reveal large differences in mRNA-specific translation activity but cannot identify the causative mRNA features. We developed direct analysis of ribosome targeting (DART) and used it to dissect regulatory elements within 5' untranslated regions that confer 1,000-fold differences in ribosome recruitment in biochemically accessible cell lysates.
View Article and Find Full Text PDFPurpose: To determine the rate of moderate and severe vision loss following herpes zoster ophthalmicus (HZO) and to identify associated factors.
Design: Retrospective cohort study.
Methods: All subjects with acute HZO seen at a single center from 2006 to 2016 were included in the study.
Long noncoding RNAs have recently been discovered to comprise a sizeable fraction of the RNA World. The scope of their functions, physical organization, and disease relevance remain in the early stages of characterization. Although many thousands of lncRNA transcripts recently have been found to emanate from the expansive DNA between protein-coding genes in animals, there are also hundreds that have been found in simple eukaryotes.
View Article and Find Full Text PDFTelomerase is a ribonucleoprotein that maintains the ends of linear chromosomes in most eukaryotes. Loss of telomerase activity results in shortening of telomeric DNA and eventually a specific G2/M cell-cycle arrest known as senescence. In humans, telomere shortening occurs during aging, while inappropriate activation of telomerase is associated with approximately 90% of cancers.
View Article and Find Full Text PDFThe enzymatic ribonucleoprotein telomerase maintains telomeres in many eukaryotes, including humans, and plays a central role in aging and cancer. Saccharomyces cerevisiae telomerase RNA, TLC1, is a flexible scaffold that tethers telomerase holoenzyme protein subunits to the complex. Here we test the hypothesis that a lengthy conserved region of the Est1-binding TLC1 arm contributes more than simply Est1-binding function.
View Article and Find Full Text PDFTelomerase catalyzes the addition of nucleotides to the ends of chromosomes to complete genomic DNA replication in eukaryotes and is implicated in multiple diseases, including most cancers. The core enzyme is composed of a reverse transcriptase and an RNA subunit, which provides the template for DNA synthesis. Despite extensive divergence at the sequence level, telomerase RNAs share several structural features within the catalytic core, suggesting a conserved enzyme mechanism.
View Article and Find Full Text PDFPurpose: Mutations in the visual system homeobox 1 (VSX1) gene have been described at a low frequency in keratoconus and posterior polymorphous corneal dystrophy (PPCD). The putative role is controversial for several reasons, including a lack of mutations detected in other population cohorts. This study aims to determine whether VSX1 contributes to the genetic pathogenesis of keratoconus and PPCD in a New Zealand population, and includes analysis of a Polynesian population.
View Article and Find Full Text PDFHow pseudouridylation (Ψ), the most common and evolutionarily conserved modification of rRNA, regulates ribosome activity is poorly understood. Medically, Ψ is important because the rRNA Ψ synthase, DKC1, is mutated in X-linked dyskeratosis congenita (X-DC) and Hoyeraal-Hreidarsson (HH) syndrome. Here, we characterize ribosomes isolated from a yeast strain in which Cbf5p, the yeast homolog of DKC1, is catalytically impaired through a D95A mutation (cbf5-D95A).
View Article and Find Full Text PDFRibosomal RNA (rRNA) is transcribed from the ribosomal DNA (rDNA) genes by RNA polymerase I (Pol I). Despite being responsible for the majority of transcription in growing cells, Pol I regulation is poorly understood compared to Pol II. To gain new insights into rDNA transcriptional regulation, we developed a genetic assay in Saccharomyces cerevisiae that detects alterations in transcription from the centromere-proximal rDNA gene of the tandem array.
View Article and Find Full Text PDFObjective: To compare the results of Proview pressure phosphene tonometry (PPPT) performed by the patient and an examiner with Goldmann applanation tonometry (GAT).
Methods: A comparative case series of 96 (192 eyes) consecutive patients from a glaucoma clinic was conducted. Intraocular pressure (IOP) was measured with GAT by one examiner, PPPT by another examiner, and PPPT by the patient.