Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 28
Filter
Add more filters










Publication year range
1.
Biochem Biophys Res Commun ; 415(1): 193-9, 2011 Nov 11.
Article in English | MEDLINE | ID: mdl-22033415

ABSTRACT

While mammalian DNA polymerase ß (Pol ß), which is a member of the Pol X family, play important roles in base excision repair (BER) that efficiently removes DNA base lesions arising from both endogenous and exogenous agents, this protein has been found only a subset of animals. To understand natural evolution of this enzyme, we isolated and characterized Pol ß from jellyfish Aurelia sp.1. (AsPol ß). Despite of phylogenetic distance and environmental differences between jellyfish and mammals, in vitro assays showed biochemical characteristics of AsPol ß were very similar to those of a mammalian counterpart. We also searched two other homologs of mammalian genes that were involved in short patch (sp) BER in the nucleotide sequence database, and found that both of these homologs were encoded in the genomes of a lineage from Cnidarians through mammals and Arthropods. This study suggests that a DNA repair mechanism resembling mammalian sp-BER may be largely limited to a subset of animals. On the basis of our findings and previous reports, we discuss possible evolutional model of Pol ß and the other members of the Pol X family.


Subject(s)
DNA Polymerase beta/metabolism , DNA Repair , Scyphozoa/enzymology , Amino Acid Sequence , Animals , DNA Ligase ATP , DNA Ligases/chemistry , DNA Ligases/genetics , DNA Ligases/metabolism , DNA Polymerase beta/chemistry , DNA Polymerase beta/classification , DNA Polymerase beta/genetics , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Evolution, Molecular , Molecular Sequence Data , Phylogeny , Poly-ADP-Ribose Binding Proteins , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , X-ray Repair Cross Complementing Protein 1 , Xenopus Proteins
2.
Nihon Rinsho ; 68 Suppl 7: 787-91, 2010 Jul.
Article in Japanese | MEDLINE | ID: mdl-20960873
3.
FEBS J ; 276(4): 943-63, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19154342

ABSTRACT

Replication protein A (RPA) complex has been shown, using both in vivo and in vitro approaches, to be required for most aspects of eukaryotic DNA metabolism: replication, repair, telomere maintenance and homologous recombination. Here, we review recent data concerning the function and biological importance of the multi-RPA complex. There are distinct complexes of RPA found in the biological kingdoms, although for a long time only one type of RPA complex was believed to be present in eukaryotes. Each complex probably serves a different role. In higher plants, three distinct large and medium subunits are present, but only one species of the smallest subunit. Each of these protein subunits forms stable complexes with their respective partners. They are paralogs as complex. Humans possess two paralogs and one analog of RPA. The multi-RPA system can be regarded as universal in eukaryotes. Among eukaryotic kingdoms, paralogs, orthologs, analogs and heterologs of many DNA synthesis-related factors, including RPA, are ubiquitous. Convergent evolution seems to be ubiquitous in these processes. Using recent findings, we review the composition and biological functions of RPA complexes.


Subject(s)
Cell Cycle/physiology , DNA Repair/physiology , Replication Protein A/physiology , Animals , DNA/metabolism , Humans , Phylogeny , Plant Proteins/genetics , Plant Proteins/physiology , Replication Protein A/genetics
4.
Biochimie ; 91(2): 165-70, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18706967

ABSTRACT

Four types of DNA polymerase (Pol beta, Pol lambda, Pol mu and TdT) have been identified in eukaryotes as members of the polymerase X-family. Only vertebrates have all four types of enzyme. Plants and fungi have one or two X-family polymerases, while protostomes, such as fruit flies and nematodes, do not appear to have any. It is possible that the well-known metabolic pathways in which these enzymes are involved are restricted to the vertebrate world. The distribution of the DNA polymerases involved in DNA repair across the various biological kingdoms differs from that of the DNA polymerases involved in chromosomal DNA replication. In this review, we focus on the interesting pattern of distribution of the X-family enzymes across biological kingdoms and speculate on their roles.


Subject(s)
DNA-Directed DNA Polymerase/classification , DNA-Directed DNA Polymerase/metabolism , Eukaryotic Cells/metabolism , DNA Repair , DNA-Directed DNA Polymerase/genetics , Evolution, Molecular
6.
Planta ; 227(6): 1233-41, 2008 May.
Article in English | MEDLINE | ID: mdl-18247046

ABSTRACT

In plants, there are no DNA polymerase beta (Pol beta) and DNA ligase III (Lig3) genes. Thus, the plant short-patch base excision repair (short-patch BER) pathway must differ considerably from that in mammals. We characterized the rice (Oryza Sativa L. cv. Nipponbare) homologue of the mammalian X-ray repair cross complementing 1 (XRCC1), a well-known BER protein. The plant XRCC1 lacks the N-terminal domain (NTD) which is required for Pol beta binding and is essential for mammalian cell survival. The recombinant rice XRCC1 (OsXRCC1) protein binds single-stranded DNA (ssDNA) as well as double-stranded DNA (dsDNA) and also interacts with rice proliferating cell nuclear antigen (OsPCNA) in a pull-down assay. Through immunoprecipitation, we demonstrated that OsXRCC1 forms a complex with PCNA in vivo. OsXRCC1 mRNA was expressed in all rice organs and was induced by application of bleomycin, but not of MMS, H(2)O(2) or UV-B. Bleomycin also increased the fraction of OsXRCC1 associated with chromatin. These results suggest that OsXRCC1 contributes to DNA repair pathways that differ from the mammalian BER system.


Subject(s)
DNA Repair , DNA-Binding Proteins/metabolism , Plant Proteins/metabolism , Proliferating Cell Nuclear Antigen/metabolism , Cell Survival , Chromatin/genetics , Chromatin/physiology , Cloning, Molecular , DNA-Binding Proteins/genetics , Oryza/genetics , Oryza/growth & development , Oryza/metabolism , Plant Leaves/metabolism , Plant Shoots/metabolism , Recombinant Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Subcellular Fractions/metabolism , X-ray Repair Cross Complementing Protein 1
7.
Plant Mol Biol ; 61(1-2): 227-40, 2006 May.
Article in English | MEDLINE | ID: mdl-16786303

ABSTRACT

The human UV-damaged DNA binding protein (UV-DDB), a heterodimeric protein composed of 127 kDa (UV-DDB1) and 48 kDa (UV-DDB2) subunits, has been shown to be involved in DNA repair. To elucidate the in vivo function of plant UV-DDB2, we have analyzed T-DNA insertion mutants of the Arabidopsis thaliana UV-DDB2 subunit (atuv-ddb2 mutants) and AtUV-DDB2 RNAi silenced plants (atuv-ddb2 silenced plants). atuv-ddb2 mutants and atuv-ddb2 silenced plants were both viable, suggesting that AtUV-DDB2 is not essential for survival. Interestingly, both plant types showed a dwarf phenotype, implying impaired growth of the meristem. To the best of our knowledge, this is the first occasion that a dwarf phenotype has been found to be associated with a UV-DDB2 mutation in either plants or animals. The mutants also demonstrated increased sensitivity to UV irradiation, methyl methanesulfonate and hydrogen peroxide treatment, indicating that AtUV-DDB2 is also involved in DNA repair. Our results lead us to suggest that not only does AtUV-DDB2 function in DNA repair, it also has a direct or indirect influence on cell proliferation in the plant meristem.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis Proteins/physiology , Arabidopsis/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/physiology , Mutagenesis, Insertional , RNA Interference , Arabidopsis/anatomy & histology , Arabidopsis/radiation effects , Arabidopsis Proteins/antagonists & inhibitors , Cell Proliferation , DNA Repair/genetics , DNA, Bacterial/metabolism , DNA-Binding Proteins/antagonists & inhibitors , Genetic Complementation Test , Hydrogen Peroxide/pharmacology , Meristem/cytology , Meristem/genetics , Meristem/metabolism , Methyl Methanesulfonate/pharmacology , Mutation , Phenotype , Plant Roots/cytology , Plant Roots/genetics , Plant Roots/metabolism , RNA, Small Interfering/metabolism
8.
Biochem Biophys Res Commun ; 345(4): 1283-91, 2006 Jul 14.
Article in English | MEDLINE | ID: mdl-16730655

ABSTRACT

The RecQ family of DNA helicases is conserved throughout the biological kingdoms. In this report, we have characterized four RecQ homologues clearly expressed in rice. OsRecQ1, OsRecQ886, and OsRecQsim expressions were strongly detected in meristematic tissues. Transcription of the OsRecQ homologues was differentially induced by several types of DNA-damaging agents. The expression of four OsRecQ homologues was induced by MMS and bleomycin. OsRecQ1 and OsRecQ886 were induced by H(2)O(2), and MitomycinC strongly induced the expression of OsRecQ1. Transient expression of OsRecQ/GFP fusion proteins demonstrated that OsRecQ2 and OsRecQ886 are found in nuclei, whereas OsRecQ1 and OsRecQsim are found in plastids. Neither OsRecQ1 nor OsRecQsim are induced by light. These results indicate that four of the RecQ homologues have different and specific functions in DNA repair pathways, and that OsRecQ1 and OsRecQsim may not involve in plastid differentiation but different aspects of a plastid-specific DNA repair system.


Subject(s)
Adenosine Triphosphatases/genetics , DNA Helicases/genetics , Oryza/genetics , Plant Proteins/genetics , Adenosine Triphosphatases/metabolism , Amino Acid Sequence , Bleomycin/toxicity , Cloning, Molecular , DNA Damage , DNA Helicases/metabolism , DNA Repair , Gene Expression Profiling , Gene Expression Regulation, Developmental/drug effects , Gene Expression Regulation, Developmental/radiation effects , Gene Expression Regulation, Enzymologic/drug effects , Gene Expression Regulation, Enzymologic/radiation effects , Gene Expression Regulation, Plant/drug effects , Gene Expression Regulation, Plant/radiation effects , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Hydrogen Peroxide/toxicity , In Situ Hybridization , Isoenzymes/genetics , Isoenzymes/metabolism , Methyl Methanesulfonate/toxicity , Microscopy, Fluorescence , Molecular Sequence Data , Oryza/enzymology , Oryza/growth & development , Phylogeny , Plant Proteins/metabolism , RecQ Helicases , Reverse Transcriptase Polymerase Chain Reaction , Sequence Alignment , Sequence Homology, Amino Acid
9.
J Steroid Biochem Mol Biol ; 99(2-3): 100-7, 2006 May.
Article in English | MEDLINE | ID: mdl-16621516

ABSTRACT

Beta-sitosterol-3-O-beta-D-glucopyranoside (compound 1), a steroidal glycoside isolated from onion (Allium cepa L.) selectively inhibited the activity of mammalian DNA polymerase lambda (pol lambda) in vitro. The compound did not influence the activities of replicative DNA polymerases such as alpha, delta and epsilon, but also showed no effect even on the activity of pol beta which is thought to have a very similar three-dimensional structure to the pol beta-like region of pol lambda. Since parts of compound 1 such as beta-sitosterol (compound 2) and D-glucose (compound 3) did not influence the activities of any enzymes tested, the converted structure of compounds 2 and 3 might be important for pol lambda inhibition. The inhibitory effect of compound 1 on both intact pol lambda (i.e. residues 1-575) and a truncated pol lambda lacking the N-terminal BRCA1 C-terminus (BRCT) domain (133-575, del-1 pol lambda) was dose-dependent, and 50% inhibition was observed at a concentration of 9.1 and 5.4 microM, respectively. The compound 1-induced inhibition of del-1 pol lambda activity was non-competitive with respect to both the DNA template-primer and the dNTP substrate. On the basis of these results, the pol lambda inhibitory mechanism of compound 1 is discussed.


Subject(s)
DNA Polymerase beta/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Eukaryotic Cells/enzymology , Glucosides/pharmacology , Sitosterols/pharmacology , Animals , Binding Sites/genetics , Catalysis , Cattle , DNA Polymerase beta/chemistry , DNA Polymerase beta/genetics , Dose-Response Relationship, Drug , Drosophila melanogaster/enzymology , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/isolation & purification , Glucose/chemistry , Glucosides/chemistry , Glucosides/isolation & purification , Humans , Kinetics , Magnetic Resonance Spectroscopy , Molecular Structure , Mutation/genetics , Onions/chemistry , Peptide Fragments/chemistry , Rats , Sitosterols/chemistry , Sitosterols/isolation & purification , Structure-Activity Relationship
10.
Kansenshogaku Zasshi ; 80(2): 97-102, 2006 Mar.
Article in Japanese | MEDLINE | ID: mdl-16629493

ABSTRACT

Isolated of multidrug resistance Pseudomonas aeruginosa (MDRP) that the receptivity pattern of the antimicrobial suscepti respectively resembled isolated from clinical specimens (sputum) in two patients of each internal medicine ward in Kitasato University East Hospital for two days from September 18 and 20, 2004. Both of bacteria were formed small colonies of a smooth-type on dollargalluskey improvement-type BTB agar plates, and the judgment of ClassB (metallo)-beta-lactamase by biochemical properties and disk diffusion method sodium mercaoto-acetic acid (SMA) was mutually corresponding. Moreover, it was same serotype C according to the serotype, and it was confirmed that it was the same bacterial strain from the molecular epidemiology analysis by Random amplified polymorphic DNA polymerase chain reaction (Random amplified polymorphic DNA polymerase chain reaction: RAPD). From the investigation of clinical backgrounds of two patients who isolated bacterial strains, September 18, 2004. 10 : 20 a.m., and 10 : 40 a.m., other chances that can become with contact infection in this hospital, except conducted X-Ray or roentgenograph of the chest and abdomen of Portable X-ray device continuously done by one radiation technician was not seen. Because it had turned out that a radiation technician who had taken charge had been neglecting the hand washing at the time of each X-Ray or roentgenograph, it was guessed the case with nosocomial infection by contact infection occurred via specific radiation technician.


Subject(s)
Cross Infection/epidemiology , Drug Resistance, Multiple, Bacterial , Equipment Contamination , Pseudomonas Infections/epidemiology , Radiography/instrumentation , Aged, 80 and over , Hand Disinfection , Hospitals, University , Humans , Male , Middle Aged , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Radiology Department, Hospital , Workforce
11.
Arch Biochem Biophys ; 446(1): 69-76, 2006 Feb 01.
Article in English | MEDLINE | ID: mdl-16405901

ABSTRACT

5-(Hydroxymethyl)-2-furfural (HMF), a pyrolysate of carbohydrate isolated from instant coffee (Coffea arabica L.), selectively inhibits the activities of mammalian DNA polymerase lambda (pol lambda) and terminal deoxynucleotidyltransferase (TdT) which are family X pols, in vitro. The compound influenced neither the activities of replicative DNA polymerases such as alpha, delta, and epsilon, nor even the activity of pol beta which is from the same family and thought to have a very similar three-dimensional structure to the pol beta-like region of pol lambda. Since parts of HMF such as furan, furfuryl alcohol, and 2-furaldehyde did not influence the activities of any enzymes tested, the substituted form of furan with a hyroxymethyl group and a formyl group might be important for the inhibition of pol lambda and TdT. The inhibitory effect of HMF on intact pol lambda (i.e., residues 1-575), a truncated pol lambda lacking the N-terminal BRCA1 C-terminus domain (133-575, del-1 pol lambda) and another truncated pol lambda lacking the N-terminal proline-rich region (245-575, del-2 pol lambda) was dose-dependent, and 50% inhibition was observed at a concentration of 26.1, 10.3, and 4.6 microM, respectively. The IC(50) value of HMF for TdT was the same as that for del-2 pol lambda (5.5 microM). The HMF-induced inhibition of both pol lambda and TdT activities was competitive with respect to both the DNA template-primer and the dNTP substrate. On the basis of these results, HMF was suggested to bind to the pol beta-like region of pol lambda and TdT.


Subject(s)
DNA Nucleotidylexotransferase/antagonists & inhibitors , DNA Polymerase beta/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Furaldehyde/analogs & derivatives , Animals , Binding Sites , Cattle , DNA Nucleotidylexotransferase/metabolism , DNA Polymerase beta/metabolism , DNA-Directed DNA Polymerase/metabolism , Enzyme Inhibitors/chemistry , Furaldehyde/chemistry , Furaldehyde/pharmacology , Nucleic Acid Synthesis Inhibitors , Substrate Specificity , Templates, Genetic
12.
Biochem Biophys Res Commun ; 339(3): 949-55, 2006 Jan 20.
Article in English | MEDLINE | ID: mdl-16325764

ABSTRACT

Tocotrienols, vitamin E compounds that have an unsaturated side chain with three double bonds, selectively inhibited the activity of mammalian DNA polymerase lambda (pol lambda) in vitro. These compounds did not influence the activities of replicative pols such as alpha, delta, and epsilon, or even the activity of pol beta which is thought to have a very similar three-dimensional structure to the pol beta-like region of pol lambda. Since delta-tocotrienol had the strongest inhibitory effect among the four (alpha- to delta-) tocotrienols, the isomer's structure might be an important factor in the inhibition of pol lambda. The inhibitory effect of delta-tocotrienol on both intact pol lambda (residues 1-575) and a truncated pol lambda lacking the N-terminal BRCA1 C-terminus (BRCT) domain (residues 133-575, del-1 pol lambda) was dose-dependent, with 50% inhibition observed at a concentration of 18.4 and 90.1microM, respectively. However, del-2 pol lambda (residues 245-575) containing the C-terminal pol beta-like region was unaffected. Tocotrienols also inhibited the proliferation of and formation of tubes by bovine aortic endothelial cells, with delta-tocotrienol having the greatest effect. These results indicated that tocotrienols targeted both pol lambda and angiogenesis as anti-cancer agents. The relationship between the inhibition of pol lambda and anti-angiogenesis by delta-tocotrienol was discussed.


Subject(s)
DNA Polymerase III/antagonists & inhibitors , DNA Polymerase beta/antagonists & inhibitors , Endothelial Cells/drug effects , Endothelial Cells/physiology , Neovascularization, Physiologic/drug effects , Neovascularization, Physiologic/physiology , Tocotrienols/administration & dosage , Animals , Cattle , Cell Proliferation/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Enzyme Inhibitors/administration & dosage
13.
DNA Repair (Amst) ; 5(1): 80-8, 2006 Jan 05.
Article in English | MEDLINE | ID: mdl-16140596

ABSTRACT

A novel RecA-like protein, differing from Dmc1 and Rad51, was characterized in Oryza sativa L. cv. Nipponbare. Because the protein is homologous to bacterial RadA, the gene was designated OsRadA. The open reading frame was predicted to encode a 66kDa protein of 619 amino acid residues and was found in plants but not animals or yeast. OsRadA showed D-loop and single-stranded DNA-dependent ATPase activities. Gene expression was found to be high in meristematic tissues, and was localized in the nucleus. An RNAi mutant of Arabidopsis thaliana RadA (AtRadA) was sensitive to mutagenic agents such as UV and MMC, suggesting that RadA functions in DNA repair.


Subject(s)
DNA Repair/physiology , Oryza/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Arabidopsis/drug effects , Arabidopsis/radiation effects , Arabidopsis Proteins/drug effects , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/radiation effects , Archaeal Proteins/chemistry , Archaeal Proteins/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Cell Proliferation , Cloning, Molecular , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Plant , Mitomycin/adverse effects , Molecular Sequence Data , Mutation , Oryza/cytology , Rec A Recombinases/chemistry , Rec A Recombinases/metabolism , Sequence Homology, Amino Acid , Subcellular Fractions , Ultraviolet Rays/adverse effects
15.
Biochim Biophys Acta ; 1725(3): 298-304, 2005 Oct 10.
Article in English | MEDLINE | ID: mdl-16099107

ABSTRACT

Studies of mammalian terminal deoxyribonucleotidyltransferase (TdT) are facilitated by use of inhibitors that selectively knock down the activity of the enzyme. We have screened for selective inhibitors of TdT and identified a natural compound with this property in the Japanese vegetable, Arctium lappa. The compound has little effect on the activities of mammalian DNA polymerases, such as alpha, beta, delta or lambda polymerase, and prokaryotic DNA polymerases, such as Taq DNA polymerase, T4 DNA polymerase and Klenow fragment. H1- and C13-NMR spectroscopic analyses showed the compound to be baicalin, a compound previously reported as an anti-inflammatory or antipyretic agent. The IC50 value of baicalin to TdT was 18.6 microM. We also found that genistin, a baicalin derivative known to be antimutagenic, more selectively inhibited TdT activity than baicalin, although its IC50 value was weaker (28.7 microM). Genistin and baicalin also inhibited the activity of truncated TdT (the so-called pol beta core domain) in which the BRCT motif was deleted in its N-terminal region. In kinetic analyses, inhibition by either genistin or baicalin was competitive with the primer and non-competitive with the dNTP substrate. The compounds may, therefore, bind directly to the primer-binding site of TdT and simultaneously disturb dNTP substrate incorporation into the primer. Genistin and baicalin should prove to be useful agents for studying TdT.


Subject(s)
DNA Nucleotidylexotransferase/antagonists & inhibitors , Flavonoids/pharmacology , Isoflavones/pharmacology , Teprotide/pharmacology , Animals , DNA Polymerase I/antagonists & inhibitors , DNA Polymerase III/antagonists & inhibitors , DNA Polymerase beta/antagonists & inhibitors , DNA Primers , Flavanones/pharmacology , Humans , Kinetics , Poly C/pharmacology , Rats , Serum Albumin, Bovine/pharmacology , Taq Polymerase/antagonists & inhibitors
16.
Biochem Biophys Res Commun ; 334(1): 43-50, 2005 Aug 19.
Article in English | MEDLINE | ID: mdl-15993837

ABSTRACT

Previously, we described a novel DNA polymerase, designated as OsPolI-like, from rice. The OsPolI-like showed a high degree of sequence homology with the DNA polymerase I of cyanobacteria and was localized in the plastid. Here, we describe two PolI-like polymerases, designated as AtPolI-like A and AtPolI-like B, from Arabidopsis thaliana. In situ hybridization analysis demonstrated expression of both mRNAs in proliferating tissues such as the shoot apical meristem. Analysis of the localizations of GFP fusion proteins showed that AtPolI-like A and AtPolI-like B were localized to plastids. AtPolI-like B expression could be induced by exposure to the mutagen H(2)O(2). These results suggested that AtPolI-like B has a role in the repair of oxidation-induced DNA damage. Our data indicate that higher plants possess two plastid DNA polymerases that are not found in animals and yeasts.


Subject(s)
Arabidopsis/genetics , Arabidopsis/metabolism , DNA Polymerase I/genetics , DNA Polymerase I/metabolism , Plastids/genetics , Plastids/metabolism , Amino Acid Sequence , DNA Polymerase I/chemistry , Molecular Sequence Data , Plant Structures/genetics , Plant Structures/metabolism , Sequence Homology, Amino Acid , Tissue Distribution
17.
FEBS J ; 272(13): 3270-81, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15978034

ABSTRACT

Replication protein A (RPA), a heterotrimeric protein composed of 70, 32 and 14-kDa subunits, has been shown to be essential for DNA replication, repair, recombination, and transcription. Previously, we found that, in two seed plants, rice and Arabidopsis, there are two different types of RPA70-kDa subunit. Substantial biochemical and genetic characterization of these two subunits, termed OsRPA70a and OsRPA70b or AtRPA70a and AtRPA70b, respectively, is described in this report. Inactivation of AtRPA70a by transfer DNA insertion or RNA interference is lethal, so the complex containing RPA70a may be essential for DNA replication. Transfer DNA insertion and RNAi lines for AtRPA70b are morphologically normal, albeit hypersensitive to certain mutagens, such as UV-B and methyl methanesulfonate, suggesting that RPA70b functions mostly in DNA repair. In two-hybrid, pull-down and coexpression analysis, OsRPA70b was found to interact more selectively than OsRPA70a with OsRPA32. The data suggest that two different types of RPA heterotrimer are present in seed plants, and that there may be additional 32 and 14-kDa subunit homologs that interact with OsRPA70a. Each of the two probable plant RPA complexes may have different roles in DNA metabolism.


Subject(s)
Arabidopsis/genetics , DNA Replication , DNA, Plant , DNA, Single-Stranded/metabolism , DNA-Binding Proteins/genetics , Oryza/genetics , Arabidopsis/cytology , Arabidopsis/metabolism , Cloning, Molecular , DNA, Bacterial/genetics , DNA, Bacterial/metabolism , DNA, Complementary/chemistry , DNA, Complementary/genetics , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Plant/drug effects , Mutation , Oryza/cytology , Oryza/drug effects , Protein Subunits , RNA, Small Interfering/pharmacology , Replication Protein A
18.
J Plant Res ; 118(2): 91-7, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15806324

ABSTRACT

Proliferating cell nuclear antigen (PCNA) is an essential protein for both DNA replication and DNA repair. In the present study using two-hybrid analysis with PCNA from rice, Oryza sativa L. cv. Nipponbare (OsPCNA), we found that OsPCNA interacted with rice DnaJ protein. We have identified DnaJ and designated it as OsDnaJ. OsDnaJ was able to bind to OsPCNA in vitro. Transcripts of OsDnaJ were found to be strongly expressed in the proliferating cells. mRNA of DnaJ was induced by UV and DNA-damaging agents such as H2O2. The expression patterns of OsPCNA were almost the same as OsDnaJ. The relationship between OsPCNA and OsDnaJ is discussed.


Subject(s)
DNA Damage/physiology , Heat-Shock Proteins/physiology , Oryza/physiology , Plant Proteins/physiology , Proliferating Cell Nuclear Antigen/physiology , Amino Acid Sequence , Cells, Cultured , Chromosome Mapping , DNA, Plant , Gene Expression Regulation, Plant , HSP40 Heat-Shock Proteins , Molecular Sequence Data , Oryza/genetics , Sequence Homology, Amino Acid , Two-Hybrid System Techniques
19.
Biochem Biophys Res Commun ; 329(2): 668-72, 2005 Apr 08.
Article in English | MEDLINE | ID: mdl-15737637

ABSTRACT

We isolated and characterized the rice homologue of the DNA repair gene Snm1 (OsSnm1). The length of the cDNA was 1862bp; the open reading frame encoded a predicted product of 485 amino acid residues with a molecular mass of 53.2kDa. The OsSnm1 protein contained the conserved beta-lactamase domain in its internal region. OsSnm1 was expressed in all rice organs. The expression was induced by MMS, H(2)O(2), and mitomycin C, but not by UV. Transient expression of an OsSnm1/GFP fusion protein in onion epidermal cells revealed the localization of OsSnm1 to the nucleus. These results suggest that OsSnm1 is involved not only in the repair of DNA interstrand crosslinks, but also in various other DNA repair pathways.


Subject(s)
Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , DNA Damage/physiology , Oryza/genetics , Oryza/metabolism , Subcellular Fractions/metabolism , Amino Acid Sequence , Cells, Cultured , Gene Expression Regulation/physiology , Molecular Sequence Data , Molecular Weight , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Tissue Distribution
20.
Eur J Biochem ; 271(13): 2799-807, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15206945

ABSTRACT

Little is known about the functions of DNA polymerase lambda (Pol lambda) recently identified in mammals. From the genomic sequence information of rice and Arabidopsis, we found that Pol lambda may be the only member of the X-family in higher plants. We have succeeded in isolating the cDNA and recombinant protein of Pol lambda in a higher plant, rice (Oryza sativa L. cv. Nipponbare) (OsPol lambda). OsPol lambda had activities of DNA polymerase, terminal deoxyribonucleotidyl transferase and deoxyribose phosphate lyase, a marker enzyme for base excision repair. It also interacted with rice proliferating cell nuclear antigen (OsPCNA) in a pull-down assay. OsPCNA increased the processivity of OsPol lambda. Northern blot analysis showed that the level of OsPol lambda expression correlated with cell proliferation in meristematic and meiotic tissues, and was induced by DNA-damaging treatments. These properties suggest that plant Pol lambda is a DNA repair enzyme which functions in plant meristematic and meiotic tissues, and that it can substitute for Pol beta and terminal deoxyribonucleotidyl transferase.


Subject(s)
DNA Polymerase beta/metabolism , DNA Repair , Meiosis , Meristem/enzymology , Oryza/enzymology , Amino Acid Sequence , DNA Polymerase beta/chemistry , Humans , Molecular Sequence Data , Phylogeny , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid
SELECTION OF CITATIONS
SEARCH DETAIL
...