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The Journal of Investigative Dermatology Jun 2022The ubiquitin ligase NEDD4-1 plays key roles in organ development, tissue homeostasis, and cancer, but its functions in the skin are largely unknown. In this study, we...
The ubiquitin ligase NEDD4-1 plays key roles in organ development, tissue homeostasis, and cancer, but its functions in the skin are largely unknown. In this study, we show perturbations in keratinocyte (KC) proliferation and terminal differentiation, epidermal barrier function, and hair follicle cycling as well as increased UV-induced apoptosis in mice lacking NEDD4-1 in KCs. In particular, re-epithelialization of full-thickness excisional wounds was delayed in the mutant mice. This was caused by severely impaired migration and proliferation of NEDD4-1‒deficient KCs. Therefore, a few KCs, which had escaped recombination and expressed NEDD4-1, obtained a growth advantage and contributed to re-epithelialization. Mechanistically, NEDD4-1‒deficient KCs failed to efficiently activate the extracellular signal-regulated kinase 1/2/MAPKs and the YAP transcriptional coactivator. These results identify NEDD4-1 as an essential player in wound repair through its effect on mitogenic and motogenic signaling pathways in KCs.
Topics: Animals; Cell Proliferation; Epidermis; Homeostasis; Mice; Nedd4 Ubiquitin Protein Ligases; Re-Epithelialization; Wound Healing
PubMed: 34756879
DOI: 10.1016/j.jid.2021.09.033 -
BioEssays : News and Reviews in... Dec 2010Studies in the yeast Saccharomyces cerevisiae have validated the major features of the double-strand break repair (DSBR) model as an accurate representation of the... (Review)
Review
Meiotic versus mitotic recombination: two different routes for double-strand break repair: the different functions of meiotic versus mitotic DSB repair are reflected in different pathway usage and different outcomes.
Studies in the yeast Saccharomyces cerevisiae have validated the major features of the double-strand break repair (DSBR) model as an accurate representation of the pathway through which meiotic crossovers (COs) are produced. This success has led to this model being invoked to explain double-strand break (DSB) repair in other contexts. However, most non-crossover (NCO) recombinants generated during S. cerevisiae meiosis do not arise via a DSBR pathway. Furthermore, it is becoming increasingly clear that DSBR is a minor pathway for recombinational repair of DSBs that occur in mitotically-proliferating cells and that the synthesis-dependent strand annealing (SDSA) model appears to describe mitotic DSB repair more accurately. Fundamental dissimilarities between meiotic and mitotic recombination are not unexpected, since meiotic recombination serves a very different purpose (accurate chromosome segregation, which requires COs) than mitotic recombination (repair of DNA damage, which typically generates NCOs).
Topics: Chromosome Segregation; Crossing Over, Genetic; DNA Breaks, Double-Stranded; DNA Damage; DNA Repair; Meiosis; Mitosis; Mutation; Recombination, Genetic; Saccharomyces cerevisiae
PubMed: 20967781
DOI: 10.1002/bies.201000087 -
EMBO Reports Aug 2000It is widely accepted that the large trinucleotide repeat expansions observed in many neurological diseases occur during replication. However, genetic recombination has... (Review)
Review
It is widely accepted that the large trinucleotide repeat expansions observed in many neurological diseases occur during replication. However, genetic recombination has emerged as a major source of instability for tandem repeats, including minisatellites, and recent studies raise the possibility that it may also be responsible for trinucleotide repeat expansions. We will review data connecting tandem repeat rearrangements and recombination in humans and in eukaryotic model organisms, and discuss the possible role of recombination in trinucleotide repeat expansions in human neurological disorders.
Topics: Animals; DNA; DNA Repair; Gene Conversion; Humans; Meiosis; Minisatellite Repeats; Models, Genetic; Recombination, Genetic; Tandem Repeat Sequences; Trinucleotide Repeat Expansion
PubMed: 11265750
DOI: 10.1093/embo-reports/kvd031 -
Heredity Jul 2022Meiosis is undoubtedly the mechanism that underpins Mendelian genetics. Meiosis is a specialised, reductional cell division which generates haploid gametes (reproductive...
Meiosis is undoubtedly the mechanism that underpins Mendelian genetics. Meiosis is a specialised, reductional cell division which generates haploid gametes (reproductive cells) carrying a single chromosome complement from diploid progenitor cells harbouring two chromosome sets. Through this process, the hereditary material is shuffled and distributed into haploid gametes such that upon fertilisation, when two haploid gametes fuse, diploidy is restored in the zygote. During meiosis the transient physical connection of two homologous chromosomes (one originally inherited from each parent) each consisting of two sister chromatids and their subsequent segregation into four meiotic products (gametes), is what enables genetic marker assortment forming the core of Mendelian laws. The initiating events of meiotic recombination are DNA double-strand breaks (DSBs) which need to be repaired in a certain way to enable the homologous chromosomes to find each other. This is achieved by DSB ends searching for homologous repair templates and invading them. Ultimately, the repair of meiotic DSBs by homologous recombination physically connects homologous chromosomes through crossovers. These physical connections provided by crossovers enable faithful chromosome segregation. That being said, the DSB repair mechanism integral to meiotic recombination also produces genetic transmission distortions which manifest as postmeiotic segregation events and gene conversions. These processes are non-reciprocal genetic exchanges and thus non-Mendelian.
Topics: Chromosome Segregation; DNA Breaks, Double-Stranded; Gene Conversion; Homologous Recombination; Meiosis
PubMed: 35393552
DOI: 10.1038/s41437-022-00523-3 -
Experimental Eye Research Jul 2018Aquaporins (AQPs), ordinarily regarded as water channels, have recently been shown to participate in other cellular functions such as cell-to-cell adhesion, cell...
Aquaporins (AQPs), ordinarily regarded as water channels, have recently been shown to participate in other cellular functions such as cell-to-cell adhesion, cell migration, cell proliferation etc. The current investigation was undertaken to find out whether AQP5 water channel plays a role in corneal epithelial wound healing. Expression of AQP5 in mouse cornea and transfected Madin-Darby canine kidney (MDCK) cells was detected using immunofluorescence or EGFP tag. Cell migration and proliferation, the two major events in wound healing, were studied in vitro using cell culture scratch-wound healing model and cell proliferation assay, in vivo by conducting wound healing experiments on corneas of wild-type and AQP5 knockout mouse model and ex vivo on corneal epithelial cells isolated from wild type and AQP5 knockout mice. MDCK cells stably expressing AQP5 showed significantly higher levels of cell migration and proliferation compared to control cells. Likewise, corneal epithelial cells of wild type mouse with innate AQP5 exhibited faster wound healing than those of AQP5 knockout in vivo and under ex vivo culture conditions. In vitro, in vivo and ex vivo studies showed that presence of AQP5 improved cell migration, proliferation and wound healing. The data collected suggest that AQP5 plays a significant role in corneal epithelial wound healing.
Topics: Animals; Aquaporin 5; Blotting, Western; Cell Culture Techniques; Cell Movement; Cell Proliferation; Cornea; Dogs; Epithelium, Corneal; Fluorescent Antibody Technique, Indirect; Green Fluorescent Proteins; Madin Darby Canine Kidney Cells; Mice; Mice, Inbred C57BL; Mice, Knockout; Re-Epithelialization; Transfection; Wound Healing
PubMed: 29660329
DOI: 10.1016/j.exer.2018.04.005 -
Proceedings of the National Academy of... May 1996Recombinational repair of double-stranded DNA gaps was investigated in Ustilago maydis. The experimental system was designed for analysis of repair of an autonomously...
Recombinational repair of double-stranded DNA gaps was investigated in Ustilago maydis. The experimental system was designed for analysis of repair of an autonomously replicating plasmid containing a cloned gene disabled by an internal deletion. It was discovered that crossing over rarely accompanied gap repair. The strong bias against crossing over was observed in three different genes regardless of gap size. These results indicate that gap repair in U. maydis is unlikely to proceed by the mechanism envisioned in the double-stranded break repair model of recombination, which was developed to account for recombination in Saccharomyces cerevisiae. Experiments aimed at exploring processing of DNA ends were performed to gain understanding of the mechanism responsible for the observed bias. A heterologous insert placed within a gap in the coding sequence of two different marker genes strongly inhibited repair if the DNA was cleaved at the promoter-proximal junction joining the insert and coding sequence but had little effect on repair if the DNA was cleaved at the promoter-distal junction. Gene conversion of plasmid restriction fragment length polymorphism markers engineered in sequences flanking both sides of a gap accompanied repair but was directionally biased. These results are interpreted to mean that the DNA ends flanking a gap are subject to different types of processing. A model featuring a single migrating D-loop is proposed to explain the bias in gap repair outcome based on the observed asymmetry in processing the DNA ends.
Topics: Base Sequence; Crossing Over, Genetic; DNA Primers; DNA Repair; DNA, Fungal; Genes, Fungal; Models, Genetic; Molecular Sequence Data; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Promoter Regions, Genetic; Recombination, Genetic; Restriction Mapping; Ustilago
PubMed: 8643590
DOI: 10.1073/pnas.93.11.5419 -
International Journal of Molecular... Apr 2021Antimony is a toxic metalloid with poorly understood mechanisms of toxicity and uncertain carcinogenic properties. By using a combination of genetic, biochemical and DNA...
Complex Mechanisms of Antimony Genotoxicity in Budding Yeast Involves Replication and Topoisomerase I-Associated DNA Lesions, Telomere Dysfunction and Inhibition of DNA Repair.
Antimony is a toxic metalloid with poorly understood mechanisms of toxicity and uncertain carcinogenic properties. By using a combination of genetic, biochemical and DNA damage assays, we investigated the genotoxic potential of trivalent antimony in the model organism . We found that low doses of Sb(III) generate various forms of DNA damage including replication and topoisomerase I-dependent DNA lesions as well as oxidative stress and replication-independent DNA breaks accompanied by activation of DNA damage checkpoints and formation of recombination repair centers. At higher concentrations of Sb(III), moderately increased oxidative DNA damage is also observed. Consistently, base excision, DNA damage tolerance and homologous recombination repair pathways contribute to Sb(III) tolerance. In addition, we provided evidence suggesting that Sb(III) causes telomere dysfunction. Finally, we showed that Sb(III) negatively effects repair of double-strand DNA breaks and distorts actin and microtubule cytoskeleton. In sum, our results indicate that Sb(III) exhibits a significant genotoxic activity in budding yeast.
Topics: Antimony; DNA; DNA Breaks, Double-Stranded; DNA Damage; DNA Repair; DNA Replication; DNA Topoisomerases, Type I; Oxidative Stress; Recombination, Genetic; Recombinational DNA Repair; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Saccharomycetales; Telomere
PubMed: 33925940
DOI: 10.3390/ijms22094510 -
Cold Spring Harbor Perspectives in... Jul 2014DNA double-strand breaks are repaired by two major pathways, homologous recombination or nonhomologous end joining. The commitment to one or the other pathway proceeds... (Review)
Review
DNA double-strand breaks are repaired by two major pathways, homologous recombination or nonhomologous end joining. The commitment to one or the other pathway proceeds via different steps of resection of the DNA ends, which is controlled and executed by a set of DNA double-strand break sensors, endo- and exonucleases, helicases, and DNA damage response factors. The molecular choreography of the underlying protein machinery is beginning to emerge. In this review, we discuss the early steps of genetic recombination and double-strand break sensing with an emphasis on structural and molecular studies.
Topics: DNA Breaks, Double-Stranded; DNA Repair; Homologous Recombination; Humans; Models, Genetic; Signal Transduction
PubMed: 25081516
DOI: 10.1101/cshperspect.a017962 -
Genetics Feb 2001The SRS2 gene of Saccharomyces cerevisiae encodes a DNA helicase that is active in the postreplication repair pathway and homologous recombination. srs2 mutations are...
The SRS2 gene of Saccharomyces cerevisiae encodes a DNA helicase that is active in the postreplication repair pathway and homologous recombination. srs2 mutations are lethal in a rad54Delta background and cause poor growth or lethality in rdh54Delta, rad50Delta, mre11Delta, xrs2Delta, rad27Delta, sgs1Delta, and top3Delta backgrounds. Some of these genotypes are known to be defective in double-strand break repair. Many of these lethalities or poor growth can be suppressed by mutations in other genes in the DSB repair pathway, namely rad51, rad52, rad55, and rad57, suggesting that inhibition of recombination at a prior step prevents formation of a lethal intermediate. Lethality of the srs2Delta rad54Delta and srs2Delta rdh54Delta double mutants can also be rescued by mutations in the DNA damage checkpoint functions RAD9, RAD17, RAD24, and MEC3, indicating that the srs2 rad54 and srs2 rdh54 mutant combinations lead to an intermediate that is sensed by these checkpoint functions. When the checkpoints are intact the cells never reverse from the arrest, but loss of the checkpoints releases the arrest. However, cells do not achieve wild-type growth rates, suggesting that unrepaired damage is still present and may lead to chromosome loss.
Topics: Cell Cycle; Chromosomes; DNA Damage; DNA Helicases; DNA Repair; DNA Repair Enzymes; DNA Topoisomerases; DNA-Binding Proteins; Endodeoxyribonucleases; Exodeoxyribonucleases; Fungal Proteins; Genotype; Mutation; Phenotype; Recombination, Genetic; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; Suppression, Genetic
PubMed: 11156978
DOI: 10.1093/genetics/157.2.557 -
Genetic correlations between cartilage regeneration and degeneration reveal an inverse relationship.Osteoarthritis and Cartilage Aug 2020The etiology of osteoarthritis (OA) is unknown, however, there appears to be a significant contribution from genetics. We have identified recombinant inbred strains of...
OBJECTIVE
The etiology of osteoarthritis (OA) is unknown, however, there appears to be a significant contribution from genetics. We have identified recombinant inbred strains of mice derived from LG/J (large) and SM/J (small) strains that vary significantly in their ability to repair articular cartilage and susceptibility to post-traumatic OA due to their genetic composition. Here, we report cartilage repair phenotypes in the same strains of mice in which OA susceptibility was analyzed previously, and determine the genetic correlations between phenotypes.
DESIGN
We used 12 recombinant inbred strains, including the parental strains, to test three phenotypes: ear-wound healing (n = 263), knee articular cartilage repair (n = 131), and post-traumatic OA (n = 53) induced by the surgical destabilization of the medial meniscus (DMM). Genetic correlations between various traits were calculated as Pearson's correlation coefficients of strain means.
RESULTS
We found a significant positive correlation between ear-wound healing and articular cartilage regeneration (r = 0.71; P = 0.005). We observed a strong inverse correlation between articular cartilage regeneration and susceptibility to OA based on maximum (r = -0.54; P = 0.036) and summed Osteoarthritis Research Society International (OARSI) scores (r = -0.56; P = 0.028). Synovitis was not significantly correlated with articular cartilage regeneration but was significantly positively correlated with maximum (r = 0.63; P = 0.014) and summed (r = 0.70; P = 0.005) OARSI scores. Ectopic calcification was significantly positively correlated with articular cartilage regeneration (r = 0.59; P = 0.021).
CONCLUSIONS
Using recombinant inbred strains, our study allows, for the first time, the measurement of genetic correlations of regeneration phenotypes with degeneration phenotypes, characteristic of OA (cartilage degeneration, synovitis). We demonstrate that OA is positively correlated with synovitis and inversely correlated with the ability to repair cartilage. These results suggest an addition to the risk paradigm for OA from a focus on degeneration to regeneration.
Topics: Animals; Cartilage, Articular; Disease Models, Animal; Ear Cartilage; Ear, External; Menisci, Tibial; Mice; Mice, Inbred Strains; Osteoarthritis, Knee; Phenotype; Regeneration; Wound Healing
PubMed: 32437968
DOI: 10.1016/j.joca.2020.04.013