We demonstrate that in Saccharomyces cerevisiae, the tandem array of ribosomal RNA genes (RDN1) is a target for integration Ty1 retrotransposon results silencing transcription and transposition. elements transpose into random rDNA repeat units are mitotically stable. In addition, we have found mutation several putative modifiers RDN1 chromatin structure abolishes array. Disruption SIR2, which elevates recombination RDN1, or TOP1, increases psoralen accessibility rDNA, HTA1-HTB1, reduces...

The yeast retrotransposon Ty1 has been tagged with a reporter gene that allows selection of RNA-mediated transposition events and is applicable to the study retroelements in other organisms. HIS3 interrupted by an artificial intron (AI) antisense orientation. HIS3AI sequences were inserted into element such on sense strand element; therefore, splicing retrotransposition marked transcripts can give rise His+ cells. Fusion Ty1-H3mHIS3AI inducible GAL1 promoter resulted high frequency histidine...

Most Ty1 retrotransposons in the genome of Saccharomyces cerevisiae are transpositionally competent but rarely transpose. We screened yeast mutagenized by insertion mTn3-lacZ/LEU2 transposon for mutations that result elevated cDNA-mediated mobility, which occurs cDNA integration or recombination. Here, we describe characterization mTn3 insertions 21 RTT (regulation transposition) genes 5- to 111-fold increases mobility. These EST2, RRM3, NUT2, RAD57, RRD2, RAD50, SGS1, TEL1, SAE2, MED1,...

Genetic damage through mutations and genome rearrangements has been hypothesized to contribute aging. The specific mechanisms responsible for age-induced increases in mutation chromosome rearrangement frequencies a potential causative role DNA aging are under active investigation. Retrotransposons mobile genetic elements that cause insertion nonallelic recombination events humans other organisms. We have investigated the of endogenous Ty1 retrotransposons aging-associated instability using...

About a third of patients with acute stroke and no prior diagnosis diabetes have hyperglycaemia during the phase stroke. Whether this is an stress response or reflection underlying controversial.To assess whether impaired glucose metabolism in ischaemic previous persists after 3 months, such persistence can be predicted.Prospective observational study.We enrolled 106 history diabetes. Fasting blood glucose, serum insulin resistance index HOMA were recorded hospital stay. A standard oral...

In this study, we investigated the effects of long-term (9-month) treatment with pioglitazone (PIO; 20 mg/kg/d) in two animal models Alzheimer's disease (AD)-related neural dysfunction and pathology: PS1-KIM146V (human presenilin-1 M146V knock-in mouse) 3xTg-AD (triple transgenic mouse carrying AD-linked mutations) mice. We also on wild-type (WT) Mice were monitored for body mass changes, fasting glycemia, glucose tolerance, studied changes brain mitochondrial enzyme activity (complexes I...

Ty1, the most abundant retrotransposon in Saccharomyces cerevisiae, integrates preferentially upstream of genes transcribed by RNA polymerase III (Pol III). Targeting is likely due to interactions between Ty1 integration complex and a feature chromatin characteristic sites Pol transcription. To better understand targeting determinants, >150,000 insertions were mapped onto S. cerevisiae genome sequence. Logistic regression was used assess relationships patterns various genomic features,...

Aberrant splicing is recognized as a key contributor of hereditary disorders, yet characterizing the molecular effects splice variants an important task that poses several challenges. Here, we present protocol for in vitro assay using minigene approach, which especially useful when patient samples are not available RNA analysis or target genes isoforms expressed accessible tissues direct analysis. We describe steps design, including cloning plasmids and subsequent transfection, followed by...

ABSTRACT The genomic RNA of retroviruses and retrovirus-like transposons must be sequestered from the cellular translational machinery so that it can packaged into viral particles. Eukaryotic mRNA processing bodies (P bodies) play a central role in segregating mRNAs for storage or decay. In this work, we provide evidence Saccharomyces cerevisiae Ty1 retrotransposon is virus-like particles (VLPs) P bodies. translationally repressed, Gag, capsid binding protein, accumulates discrete...

High-level expression of a transpositionally competent Ty1 element fused to the inducible GAL1 promoter on 2 microns plasmid (pGTy1) overcomes transpositional dormancy in Saccharomyces cerevisiae. To investigate mechanisms controlling rate retrotransposition, we quantitated transposition and gene products cells induced uninduced for pGTy1. The increase was 45- 125-fold greater than RNA effected by pGTy1 induction. Translational efficiency not altered transposition-induced cells, since...

Retrotransposons can facilitate repair of broken chromosomes, and therefore an important question is whether the host activate retrotransposons in response to chromosomal lesions. Here we show that Ty1 elements, which are LTR-retrotransposons Saccharomyces cerevisiae , mobilized when DNA lesions created by loss telomere function. Inactivation telomerase yeast results progressive shortening telomeric DNA, eventually triggering a DNA-damage checkpoint arrests cells G 2 /M. A fraction cells,...

Abstract rtt4-1 (regulator of Ty transposition) is a cellular mutation that permits high level spontaneous Ty1 retrotransposition in Saccharomyces cerevisiae. The RTT4 gene allelic with SSL2 (RAD25), which encodes DNA helicase present basal transcription (TFIIH) and nucleotide excision repair (NER) complexes. ssl2-rtt (rtt4-1) stimulates retrotransposition, but does not alter target site preferences, or increase cDNA mitotic recombination. In addition to ssl2-rtt, the ssl2-dead SSL2-1...

Group II introns are self-splicing RNAs found in eubacteria, archaea, and eukaryotic organelles. They mechanistically similar to the metazoan nuclear spliceosomal introns; therefore, group have been invoked as progenitors of pre-mRNA introns. However, ability function outside bacteria-derived organelles is debatable, since they not genomes eukaryotes. Here, we show that Lactococcus lactis Ll.LtrB intron splices accurately efficiently from different pre-mRNAs a eukaryote, Saccharomyces...

“Two independent groups of investigators have found evidence an enzyme… which synthesizes DNA from RNA template. This discovery, if upheld, will important implications… information transfer to can be inverted.” 1970, preamble refs. 1 and 2.

The genetic diversity of 32 Italian isolates feline immunodeficiency virus (FIV) was studied. Isolates were obtained from domestic cats living in different areas. Sequence data a 308 bp fragment the p25 region gag gene. Phylogenetic relationships among these sequences and previously published determined. All could be assigned to subtype B; however, four formed two separate clusters may represent out- liers. reliability classification results confirmed by repeating phylogenetic analysis with...

Abstract Despite the abundance of Ty1 RNA in Saccharomyces cerevisiae, retrotransposition is a rare event. To determine whether transpositional dormancy result defective elements, functional and alleles retrotransposon yeast genome were quantitated. Genomic elements isolated by gap repair-mediated recombination pGTy1-H3(delta 475-3944) HIS3, multicopy plasmid containing GAL1/Ty1-H3 fusion element lacking most gag domain (TYA) protease (PR) integrase (IN) domains. Of 39 independent repaired...

Ty1 retrotransposons in Saccharomyces cerevisiae are maintained a state of transpositional dormancy. We isolated mutation, rtt100-1, that increases the transposition genomic elements 18- to 56-fold but has little effect on related Ty2 elements. rtt100-1 was shown be null allele FUS3 gene, which encodes haploid-specific mitogen-activated protein kinase. In fus3mutants, levels RNA, synthesis, and proteolytic processing were not altered relative those FUS3strains steady-state TyA, integrase,...

The yeast LTR retrotransposon Ty1 integrates preferentially into regions upstream of tRNA genes. chromatin structure transcriptionally active genes is known to be important for integration, but specific factors that enhance integration at have not been identified. Here we report the histone deacetylase, Hos2, and Trithorax-group protein, Set3, both components Set3 complex (Set3C), transposition chromosomal elements by promoting region Deletion HOS2 or SET3 reduced mobility a Ty1his3AI...