Human reveal DNA-embedded ribonucleotides as a new type of epigenetic mark.

Ribonucleoside monophosphates (rNMPs) are abundant in DNA, but their distribution and function in human nuclear genomes remain unknown. Here, we mapped nearly one million rNMPs per genome across diverse human cell types, defining a nuclear "" with non-random distribution patterns. rNMPs are enriched in C/G-rich sequences, epigenetically marked regions, and telomeres.

Characterization of a new mutation of mitochondrial ND6 gene in hepatocellular carcinoma and its effects on respiratory complex I.

Hepatocellular carcinoma (HCC) is the most common form of liver cancer, which often arises from previous liver pathologies such as HBV, HCV, and alcohol abuse. It is typically associated with an enlarged cirrhotic organ. In this study, we analyzed tumor and distal tissues from a patient who underwent liver resection for HCC with no previous pathologies and whose liver showed normal function without signs of cirrhosis.

RNA-mediated double-strand break repair by end-joining mechanisms.

Double-strand breaks (DSBs) in DNA are challenging to repair. Cells employ at least three DSB-repair mechanisms, with a preference for non-homologous end joining (NHEJ) over homologous recombination (HR) and microhomology-mediated end joining (MMEJ). While most eukaryotic DNA is transcribed into RNA, providing complementary genetic information, much remains unknown about the direct impact of RNA on DSB-repair outcomes and its role in DSB-repair via end joining.

Distinct features of ribonucleotides within genomic DNA in Aicardi-Goutières syndrome ortholog mutants of .

Ribonucleoside monophosphates (rNMPs) are abundantly found within genomic DNA of cells. The embedded rNMPs alter DNA properties and impact genome stability. Mutations in ribonuclease (RNase) H2, a key enzyme for rNMP removal, are associated with the Aicardi-Goutières syndrome (AGS), a severe neurological disorder.

rNMPID: a database for riboNucleoside MonoPhosphates in DNA.

Motivation: Ribonucleoside monophosphates (rNMPs) are the most abundant non-standard nucleotides embedded in genomic DNA. If the presence of rNMP in DNA cannot be controlled, it can lead to genome instability. The actual regulatory functions of rNMPs in DNA remain mainly unknown.

Light-strand bias and enriched zones of embedded ribonucleotides are associated with DNA replication and transcription in the human-mitochondrial genome.

Abundant ribonucleoside-triphosphate (rNTP) incorporation into DNA by DNA polymerases in the form of ribonucleoside monophosphates (rNMPs) is a widespread phenomenon in nature, resulting in DNA-structural change and genome instability. The rNMP distribution, characteristics, hotspots and association with DNA metabolic processes in human mitochondrial DNA (hmtDNA) remain mostly unknown. Here, we utilize the ribose-seq technique to capture embedded rNMPs in hmtDNA of six different cell types.

Distinct features of ribonucleotides within genomic DNA in Aicardi-Goutières syndrome (AGS)-ortholog mutants of .

Ribonucleoside monophosphates (rNMPs) are abundantly found within genomic DNA of cells. The embedded rNMPs alter DNA properties and impact genome stability. Mutations in ribonuclease (RNase) H2, a key enzyme for rNMP removal, are associated with the Aicardi-Goutières syndrome (AGS), a severe neurological disorder.

AUF1 Recognizes 8-Oxo-Guanosine Embedded in DNA and Stimulates APE1 Endoribonuclease Activity.

The existence of modified ribonucleotide monophosphates embedded in genomic DNA, as a consequence of oxidative stress conditions, including 8-oxo-guanosine and ribose monophosphate abasic site (rAP), has been recently highlighted by several works and associated with oxidative stress conditions. Although human apurinic-apyrimidinic endodeoxyribonuclease 1 (APE1), a key enzyme of the base-excision repair pathway, repairs rAP sites and canonical deoxyribose monophosphate abasic sites with similar efficiency, its incision-repairing activity on 8-oxo-guanosine is very weak. The aims of this work were to: (i) identify proteins able to specifically bind 8-oxo-guanosine embedded in DNA and promote APE1 endoribonuclease activity on this lesion, and (ii) characterize the molecular and biological relevance of this interaction using human cancer cell lines.

RESCOT: Restriction Enzyme Set and Combination Optimization Tools for rNMP Capture Techniques.

The incorporation of ribonucleoside monophosphates (rNMPs) in genomic DNA is a frequent phenomenon in many species, often associated with genome instability and disease. The ribose-seq technique is one of a few techniques designed to capture and map rNMPs embedded in genomic DNA. The first step of ribose-seq is restriction enzyme (RE) fragmentation, which cuts the genome into smaller fragments for subsequent rNMP capture.

Frequency and patterns of ribonucleotide incorporation around autonomously replicating sequences in yeast reveal the division of labor of replicative DNA polymerases.

Ribonucleoside triphosphate (rNTP) incorporation in DNA by DNA polymerases is a frequent phenomenon that results in DNA structural change and genome instability. However, it is unclear whether the rNTP incorporation into DNA follows any specific sequence patterns. We analyzed multiple datasets of ribonucleoside monophosphates (rNMPs) embedded in DNA, generated from three rNMP-sequencing techniques.

Mapping ribonucleotides embedded in genomic DNA to single-nucleotide resolution using Ribose-Map.

The most common nonstandard nucleotides found in genomic DNA are ribonucleotides. Although ribonucleotides are frequently incorporated into DNA by replicative DNA polymerases, very little is known about the distribution and signatures of ribonucleotides incorporated into DNA. Recent advances in high-throughput ribonucleotide sequencing can capture the exact locations of ribonucleotides in genomic DNA.

Gene Co-Expression Analysis of Human Reveals Functional Networks Associated with DNA Replication, DNA Damage Response, and Cell Cycle Regulation.

Ribonuclease (RNase) H2 is a key enzyme for the removal of RNA found in DNA-RNA hybrids, playing a fundamental role in biological processes such as DNA replication, telomere maintenance, and DNA damage repair. RNase H2 is a trimer composed of three subunits, being the catalytic subunit. expression levels have been shown to be upregulated in transformed and cancer cells.

Disproportionate presence of adenosine in mitochondrial and chloroplast DNA of .

Ribonucleoside monophosphates (rNMPs) represent the most common non-standard nucleotides found in the genome of cells. The distribution of rNMPs in DNA has been studied only in limited genomes. Using the ribose-seq protocol and the Ribose-Map bioinformatics toolkit, we reveal the distribution of rNMPs incorporated into the whole genome of a photosynthetic unicellular green alga, .

Genetic Characterization of Three Distinct Mechanisms Supporting RNA-Driven DNA Repair and Modification Reveals Major Role of DNA Polymerase ζ.

DNA double-stranded breaks (DSBs) are dangerous lesions threatening genomic stability. Fidelity of DSB repair is best achieved by recombination with a homologous template sequence. In yeast, transcript RNA was shown to template DSB repair of DNA.

Ribonucleotide incorporation in yeast genomic DNA shows preference for cytosine and guanosine preceded by deoxyadenosine.

Despite the abundance of ribonucleoside monophosphates (rNMPs) in DNA, sites of rNMP incorporation remain poorly characterized. Here, by using ribose-seq and Ribose-Map techniques, we built and analyzed high-throughput sequencing libraries of rNMPs derived from mitochondrial and nuclear DNA of budding and fission yeast. We reveal both common and unique features of rNMP sites among yeast species and strains, and between wild type and different ribonuclease H-mutant genotypes.

Systematic analysis of linker histone PTM hotspots reveals phosphorylation sites that modulate homologous recombination and DSB repair.

Double strand-breaks (DSBs) of genomic DNA caused by ionizing radiation or mutagenic chemicals are a common source of mutation, recombination, chromosomal aberration, and cell death. Linker histones are DNA packaging proteins with established roles in chromatin compaction, gene transcription, and in homologous recombination (HR)-mediated DNA repair. Using a machine-learning model for functional prioritization of eukaryotic post-translational modifications (PTMs) in combination with genetic and biochemical experiments with the yeast linker histone, Hho1, we discovered that site-specific phosphorylation sites regulate HR and HR-mediated DSB repair.

Capture of Ribonucleotides in Yeast Genomic DNA Using Ribose-Seq.

Experiments conducted in yeast cells have recently shown abundant presence of ribonucleotides (rNMPs) embedded both in nuclear and mitochondrial DNA. Indeed, rNMPs are the most frequent, nonstandard nucleotides found in cellular DNA. rNMPs have a highly reactive 2'-hydroxyl group in the ribose sugar that gives rise to genome instability by altering the structure, function, and properties of DNA.

Unlike the counterpart, archaeal RNase HII cannot process ribose monophosphate abasic sites and oxidized ribonucleotides embedded in DNA.

The presence of ribonucleoside monophosphates (rNMPs) in nuclear DNA decreases genome stability. To ensure survival despite rNMP insertions, cells have evolved a complex network of DNA repair mechanisms, in which the ribonucleotide excision repair pathway, initiated by type 2 RNase H (RNase HII/2), plays a major role. We recently demonstrated that eukaryotic RNase H2 cannot repair damage, that is, ribose monophosphate abasic (both apurinic or apyrimidinic) site (rAP) or oxidized rNMP embedded in DNA.

Ribose-Map: a bioinformatics toolkit to map ribonucleotides embedded in genomic DNA.

Recent advances in high-throughput sequencing techniques have made it possible to tag ribonucleoside monophosphates (rNMPs) embedded in genomic DNA for sequencing. rNMP sequencing experiments generate large, complex datasets that require efficient, scalable software that can accurately map embedded rNMPs independently of the particular sequencing technique used. Current computational pipelines designed to map rNMPs embedded in genomic DNA are customized for data generated using only one type of rNMP sequencing technique.

From "Cellular" RNA to "Smart" RNA: Multiple Roles of RNA in Genome Stability and Beyond.

Coding for proteins has been considered the main function of RNA since the "central dogma" of biology was proposed. The discovery of noncoding transcripts shed light on additional roles of RNA, ranging from the support of polypeptide synthesis, to the assembly of subnuclear structures, to gene expression modulation. Cellular RNA has therefore been recognized as a central player in often unanticipated biological processes, including genomic stability.

An Approach to Detect and Study DNA Double-Strand Break Repair by Transcript RNA Using a Spliced-Antisense RNA Template.

A double-strand break (DSB) is one of the most dangerous DNA lesion, and its repair is crucial for genome stability. Homologous recombination is considered the safest way to repair a DNA DSB and requires an identical or nearly identical DNA template, such as a sister chromatid or a homologous chromosome for accurate repair. Can transcript RNA serve as donor template for DSB repair? Here, we describe an approach that we developed to detect and study DNA repair by transcript RNA.

RNA takes over control of DNA break repair.

Small RNAs generated at DNA break sites are implicated in mammalian DNA repair. Now, a study shows that following the formation of DNA double-strand breaks, bidirectional transcription events adjacent to the break generate small RNAs that trigger the DNA damage response by local RNA:RNA interactions.

Abasic and oxidized ribonucleotides embedded in DNA are processed by human APE1 and not by RNase H2.

Ribonucleoside 5'-monophosphates (rNMPs) are the most common non-standard nucleotides found in DNA of eukaryotic cells, with over 100 million rNMPs transiently incorporated in the mammalian genome per cell cycle. Human ribonuclease (RNase) H2 is the principal enzyme able to cleave rNMPs in DNA. Whether RNase H2 may process abasic or oxidized rNMPs incorporated in DNA is unknown.