Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A mutant plasmid, pX, derived from the 1453 base pair small plasmid, YARp1 (or TRP1 RI circle), consists of 849 base pairs of DNA bearing the TRP1 gene and the ARS1 sequence of Saccharomyces cerevisiae and, unlike YARp1 and other commonly used yeast plasmids, highly multimerizes in a S. cerevisiae host. The multimerization of pX was dependent on RAD52, which is known to be necessary for homologous recombination in S. cerevisiae. Based upon this observation, a regulated system of multimerization of pX with GAL1 promoter-driven RAD52 has been developed. We conclude that the regulated multimerization of pX could provide a useful model system to study genetic recombination in the eukaryotic cell, in particular to investigate recombination intermediates and the effects of various trans-acting mutations on the multimerization and recombination of plasmids.
Mol Gen Genet 1989 Nov
PMID:Plasmid multimerization is dependent on RAD52 activity in Saccharomyces cerevisiae. 269 27

An endo-exonuclease has been purified from logarithmically growing cells of the yeast Saccharomyces cerevisiae. Identification and purification of this nuclease was facilitated by its being precipitable with an antibody raised against a previously described Neurospora crassa endo-exonuclease (Resnick, M. A., Chow, T. Y.-K. Nitiss, J., and Game, J. C. (1984) Cold Spring Harbor Symp. Quant. Biol. 49, 639-649 and T. Y.-K. Chow and M. A. Resnick (1988) Mol. Gen. Genet., in press). The enzyme which was purified to near homogeneity was composed of a molecular weight 72,000 monomer. The single-strand nuclease activity is endonucleolytic and nonprocessive, whereas the double-strand DNase activity is exonucleolytic and weakly processive. Both nuclease activities have a pH optimum of 7.5, require Mg2+ or Mn2+ but not Zn2+ or Ca2+, are not inhibited by ATP, and exhibit the same kinetics of heat inactivation. Although this protein is not the product of the RAD52 gene, the greatly reduced amounts in rad52 mutants implicate the enzyme in repair and recombination processes in both mitotic and meiotic cells.
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PMID:Purification and characterization of an endo-exonuclease from Saccharomyces cerevisiae that is influenced by the RAD52 gene. 282 28

Extracts of Rad+ and radiation-sensitive (rad) mutants of the yeast Saccharomyces cerevisiae were examined for total Mg2+-dependent alkaline deoxyribonuclease activity and the presence of a nuclease that crossreacts immunologically with an antiserum raised against an endo-exonuclease from Neurospora crassa, an enzyme exhibiting both deoxyribo- and ribonuclease activities. No significant differences were observed in total deoxyribonuclease activity between Rad+ and rad mutants. The antibody precipitable activity, however, was found to be 30%-40% of the total alkaline deoxyribonuclease activity in logarithmically growing Rad+ cells. Extracts of stationary phase cells were lacking in antibody precipitable activity. Using immunoblot methods, a 72 kDa crossreacting protein was identified from logarithmically growing cells that was absent from stationary phase cells. In all radiation-sensitive mutants examined, except rad52, at least 20% of total activity was precipitable. Extracts from logarithmically growing rad52 mutants, including a rad52::LEU2 insertion mutant, exhibited less than 10% of the Rad+ precipitable activity; however, some crossreacting material was detected. Although, the level of endo-exonuclease activity is influenced by the RAD52 gene, it is not the product of this gene. The total deoxyribonuclease and the antibody precipitable endo-exonuclease activities were also followed during meiosis. Unlike the Rad+ strain which had previously been shown to have increased levels of total and immunoprecipitable endo-exonuclease as cells underwent meiosis, the rad52 mutant exhibited no increases in either category of nuclease activity. Given the importance of the RAD52 gene in repair, recombination and mutagenesis, the endo-exonuclease may be a significant component of these processes.
Mol Gen Genet 1988 Jan
PMID:An endo-exonuclease activity of yeast that requires a functional RAD52 gene. 283 Apr 67

Drosophila P element transposase expression is limited to the germline by tissue-specific splicing of one of its three introns. Removal of this intron by mutagenesis in vitro has allowed both P element excision and transposition to be detected in Drosophila somatic tissues. In order to determine if P element transposase can function in other organisms, we have expressed modified P elements either lacking one intron or lacking all three introns in mammalian cells and yeast, respectively. Using an assay for P element excision, we have detected apparent excision events in cultured monkey cells. Furthermore, expression of the complete P element cDNA is lethal to Saccharomyces cerevisiae cells carrying a mutation in the RAD52 gene, indicating that double-stranded DNA breaks are generated, presumably by transposase action.
J Mol Biol 1988 Mar 20
PMID:Evidence for Drosophila P element transposase activity in mammalian cells and yeast. 283 97

The Drosophila melanogaster transposable element 412 is transiently unstable in Saccharomyces cerevisiae when present on a freely replicating plasmid. The 412 element undergoes recombination to form two circular molecules, a 412 deletion plasmid and, presumably, a 412 circle. The 412 deletion plasmid contains a single long terminal repeat which most likely is the result of homologous recombination within the long terminal repeats. This recombination occurs at or shortly after transformation and is independent of both the RAD52 gene product and the Flp gene of 2 micron DNA.
Mol Cell Biol 1985 Nov
PMID:Behavior of a Drosophila melanogaster transposable element in Saccharomyces cerevisiae. 301 18

Double-strand breaks in DNA are known to promote recombination in Saccharomyces cerevisiae. Yeast mating type switching, which is a highly efficient gene conversion event, is apparently initiated by a site-specific double-strand break. The 2 micrograms circle site-specific recombinase, FLP, has been shown to make double-strand breaks in its substrate DNA. By using a hybrid 2 micrograms circle::Tn5 plasmid, a portion of which resembles, in its DNA organization, the active (MAT) and the silent (HML) yeast mating type loci, it is shown that FLP mediates a conversion event analogous to mating type switching. Whereas the FLP site-specific recombination is not dependent on the RAD52 gene product, the FLP-induced conversion is abolished in a rad52 background. The FLP-promoted conversion in vivo can be faithfully reproduced by making a double-stranded gap in vitro in the vicinity of the FLP site and allowing the gap to be repaired in vivo.
Mol Cell Biol 1986 Nov
PMID:Mating type-like conversion promoted by the 2 micrograms circle site-specific recombinase: implications for the double-strand-gap repair model. 302 14

The RAD1 gene of Saccharomyces cerevisiae is required for the incision step of excision repair of damaged DNA. In this paper, we report our observations on the effect of the RAD1 gene on genetic recombination. Mitotic intrachromosomal and interchromosomal recombination in RAD+, rad1, rad52, and other rad mutant strains was examined. The rad1 deletion mutation and some rad1 point mutations reduced the frequency of intrachromosomal recombination of a his3 duplication, in which one his3 allele is deleted at the 3' end while the other his3 allele is deleted at the 5' end. Mutations in the other excision repair genes, RAD2, RAD3, and RAD4, did not lower recombination frequencies in the his3 duplication. As expected, recombination between the his3 deletion alleles in the duplication was reduced in the rad52 mutant. The frequency of HIS3+ recombinants fell synergistically in the rad1 rad52 double mutant, indicating that the RAD1 and RAD52 genes affect this recombination via different pathways. In contrast to the effect of mutations in the RAD52 gene, mutations in the RAD1 gene did not lower intrachromosomal and interchromosomal recombination between heteroalleles that carry point mutations rather than partial deletions; however, the rad1 delta mutation did lower the frequency of integration of linear plasmids and DNA fragments into homologous genomic sequences. We suggest that RAD1 plays a role in recombination after the formation of the recombinogenic substrate.
Mol Cell Biol 1988 Sep
PMID:RAD1, an excision repair gene of Saccharomyces cerevisiae, is also involved in recombination. 306 20

Novel recombinational repair of a site-specific double-strand break (DSB) in a yeast chromosome was investigated. When the recognition site for the HO endonuclease enzyme is embedded in nonyeast sequences and placed between two regions of homology, expression of HO endonuclease stimulates recombination between the homologous flanking regions to yield a deletion, the apparent product of an intrachromosomal exchange between direct repeats. This deletion-repair event is very efficient, thus preventing essentially all the potential lethality due to the persistence of a DSB. Interestingly, unlike previous studies involving spontaneous recombination between chromosomal repeats, the recombination events stimulated by HO-induced DSBs are accompanied by loss of the sequences separating the homologous regions greater than 99.5% of the time. Repair is dependent on the RAD52 gene. The deletion-repair event provides an in vivo assay for the sensitivity of any particular recognition site to HO cleavage. By taking advantage of a galactose-inducible HO gene, it has been possible to follow the kinetics of this event at the DNA level and to search for intermediates in this reaction. Deletion-repair requires approximately 45 min and is inhibited when cycloheximide is added after HO endonuclease cleavage.
Mol Cell Biol 1988 Sep
PMID:Efficient repair of HO-induced chromosomal breaks in Saccharomyces cerevisiae by recombination between flanking homologous sequences. 306 27

The roles of the RAD genes of Saccharomyces cerevisiae in the regulation of transcription of two DNA damage responsive (DDR) genes were investigated by examining the levels of the DDRA2 and DDR48 transcripts in different rad mutants after exposure to two different DNA damaging agents. Strains carrying mutations in either the RAD3, RAD6 or RAD52 genes were treated with increasing concentrations of 4-nitroquinoline-1-oxide (NQO) or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and the DDR transcript levels were determined by Northern hybridization analysis. Our results indicate that the RAD3 gene is required for DDRA2 transcript production following NQO or MNNG treatments. Strains carrying mutations in either the RAD6 or RAD52 genes show an increased level of DDRA2 transcript in undamaged cells. However, the rad6 and rad52 mutants show a normal dose-dependent increase in DDRA2 transcript levels after NQO or MNNG exposure. The DDR48 gene appears to be regulated differently from DDRA2 in that this gene is induced in rad3 cells after damaging treatment but transcript induction is severely reduced in both rad6 and rad52 mutant strains. Although the rad mutations influence the kinetics of transcript accumulation, these effects do not account for the altered dose responses of the DDRA2 and DDR48 genes. Our results also demonstrate that the regulation of DDRA2 and DDR48 transcript levels by heat shock treatment is affected less severely in the different rad strains, a result which suggests that the RAD genes play an indirect role in DDR gene control.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Gen Genet 1986 Nov
PMID:Transcriptional regulation of DNA damage responsive (DDR) genes in different rad mutant strains of Saccharomyces cerevisiae. 310 Sep 12

A circular DNA plasmid, pSR1, isolated from Zygosaccharomyces rouxii has a pair of inverted repeats consisting of completely homologous 959-base pair (bp) sequences. Intramolecular recombination occurs frequently at the inverted repeats in cells of Saccharomyces cerevisiae, as well as in Z. rouxii, and is catalyzed by a protein encoded by the R gene of its own genome. The recombination is, however, independent of the RAD52 gene of the host genome. A site for initiation of the intramolecular recombination in the S. cerevisiae host was delimited into, at most, a 58-bp region in the inverted repeats by using mutant plasmids created by linker insertion. The 58-bp region contains a pair with 14-bp dyad symmetry separated by a 3-bp spacer sequence. The recombination initiated at this site was accompanied by a high frequency of gene conversion (3 to 50% of the plasmid clones examined). Heterogeneity created by the linker insertion or by a deletion (at most 153 bp so far tested) at any place on the inverted repeats was converted to a homologous combination by the gene conversion, even in the rad52-1 mutant host. A mechanism implying branch migration coupled with DNA replication is discussed.
Mol Cell Biol 1988 Feb
PMID:Gene conversion associated with site-specific recombination in yeast plasmid pSR1. 328 Sep 74


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