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1.
World J Surg Oncol ; 18(1): 86, 2020 May 04.
Article in English | MEDLINE | ID: mdl-32366262

ABSTRACT

INTRODUCTION: The incidence of synchronous RCC and colorectal cancer is heterogeneous ranging from 0.03 to 4.85%. Instead, only one case of huge colon carcinoma and renal angiomyolipoma was reported. The treatment of synchronous kidney and colorectal neoplasm is, preferably, synchronous resection. Currently, laparoscopic approach has shown to be feasible and safe, and it has become the gold standard of synchronous resection due to advantages of minimally invasive surgery. We presented a case synchronous renal neoplasm and colorectal cancer undergone simultaneous totally robotic renal enucleation and rectal resection with primary intracorporeal anastomosis. As our knowledge, this is the first case in literature of simultaneous robotic surgery for renal and colorectal tumor. CASE PRESENTATION: A 53-year-old woman was affected by recto-sigmoid junction cancer and a solid 5 cm left renal mass. We performed a simultaneous robotic low anterior rectal resection and renal enucleation. Total operative time was 260 min with robotic time of 220 min; estimated blood loss was 150 ml; time to flatus was 72 h, and oral diet was administered 4 days after surgery. The patient was discharged on the eighth post-operative day without peri- and post-operative complication. The definitive histological examination showed a neuroendocrine tumor pT2N1 G2, with negative circumferential and distal resection margins. Renal tumor was angiomyolipoma. At 23 months follow-up, the patient is recurrence free. DISCUSSION AND CONCLUSION: As our knowledge, we described the first case in literature of simultaneous robotic anterior rectal resection and partial nephrectomy for treatment of colorectal tumor and renal mass. Robotic rectal resection with intracorporeal anastomosis surgery seems to be feasible and safe even when it is associated with simultaneous partial nephrectomy. Many features of robotic technology could be useful in combined surgery. This strategy is recommended only when patients' medical conditions allow for longer anesthesia exposure. The advantages are to avoid a delay treatment of second tumor, to reduce the time to start the post-operative adjuvant chemotherapy, to avoid a second anesthetic procedure, and to reduce the patient discomfort. However, further studies are needed to evaluate robotic approach as standard surgical strategy for simultaneous treatment of colorectal and renal neoplasm.


Subject(s)
Carcinoma, Renal Cell/surgery , Colorectal Neoplasms/surgery , Kidney Neoplasms/surgery , Neoplasms, Multiple Primary/surgery , Nephrectomy/methods , Proctectomy/methods , Robotic Surgical Procedures/methods , Anastomosis, Surgical , Carcinoma, Renal Cell/pathology , Colorectal Neoplasms/pathology , Female , Humans , Kidney/pathology , Kidney/surgery , Kidney Neoplasms/pathology , Middle Aged , Neoplasms, Multiple Primary/pathology , Operative Time , Rectum/pathology , Rectum/surgery , Time Factors , Treatment Outcome
2.
Am J Clin Pathol ; 128(6): 926-35, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18024317

ABSTRACT

Rapid methods are needed for public health and military applications to specifically identify Francisella tularensis, the causative agent of tularemia in humans. A comparative analysis of the capabilities of multiple technologies was performed using a well-defined set of organisms to determine which approach would provide the most information in the shortest time. High-resolution molecular techniques, including pulsed-field gel electrophoresis, amplified fragment length polymorphism, and ribotyping, provided subspecies level identification within approximately 24 hours after obtaining an isolate, whereas multilocus variable number tandem repeat analysis with 8 or 25 targets provided strain level discrimination within about 12 hours. In contrast, Raman spectroscopy provided species level identification in 10 minutes but could not differentiate between subspecies tularensis and holarctica.


Subject(s)
Bacterial Typing Techniques , DNA, Bacterial/analysis , Francisella tularensis/genetics , Tularemia/microbiology , Amplified Fragment Length Polymorphism Analysis , Animals , Electrophoresis, Gel, Pulsed-Field , Francisella tularensis/classification , Francisella tularensis/isolation & purification , Humans , Molecular Diagnostic Techniques , Ribotyping , Spectrum Analysis, Raman/methods
3.
Appl Environ Microbiol ; 73(22): 7465-70, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17890329

ABSTRACT

Francisella tularensis subsp. holarctica is widely disseminated in North America and the boreal and temperate regions of the Eurasian continent. Comparative genomic analyses identified a 1.59-kb genomic deletion specific to F. tularensis subsp. holarctica isolates from Spain and France. Phylogenetic analysis of strains carrying this deletion by multiple-locus variable-number tandem repeat analysis showed that the strains comprise a highly related set of genotypes, implying that these strains were recently introduced or recently emerged by clonal expansion in France and the Iberian Peninsula.


Subject(s)
Francisella tularensis/genetics , Gene Deletion , Genome, Bacterial , Cluster Analysis , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Electrophoresis, Agar Gel , France , Francisella/genetics , Francisella/isolation & purification , Francisella tularensis/classification , Francisella tularensis/isolation & purification , Genes, Bacterial/genetics , Polymerase Chain Reaction , Spain , Species Specificity
4.
J Environ Monit ; 7(12): 1313-9, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16307089

ABSTRACT

The enrichment of PCBs (polychlorobiphenyls) and PAHs (polycyclic aromatic hydrocarbons) in the sea-surface micro-layer and depth profile of these pollutants in the water column were investigated at Gerlache Inlet, Terra Nova Bay, Antarctica. Depth profile samplings were repeated three times during the Antarctic summer (from November to February). PCBs and PAHs showed a concentration range in the water column of 30-120 pg l(-1) and 150-400 pg l(-1), respectively, and these values were very much dependent on the suspended matter content. A nearly two-fold decrease in the pollutant concentration was also observed in the depth profile obtained in February, i.e. late summer, which might be correlated both with the high content of suspended matter and the reduction of the pollutant input. Moreover, isomer ratios of PAHs, such as LMW/HMW and PHE/ANT, highlight that the main PAH source might be petrogenic in nature, whereas the pyrolytic source seems to be less important. Sea surface micro-layer (SML) and sub-surface sea water (SSW) samples were simultaneously collected in the same site by a remote controlled rotating drum-based sampling system, a prototype named MUMS (Multi-User Micro-layer Sampler). Sea surface micro-layer samples showed a total content of PCBs and PAHs in the range 400-450 pg l(-1) and 2000-3000 pg l(-1), respectively, whereas the mean content of the sub-surface sea water samples was 48 pg l(-1) and 325 pg l(-1), respectively. The mean enrichment factors of PCBs and PAHs in sea-surface micro-layer were about 10 and 7, respectively. The surface excess concentrations of PCBs and PAHs were about 35 000 and 200 000, respectively. A fairly good correlation was observed between the concentration of pollutants and water solubility. Based on the assumption that POPs are confined in a very thin top layer of the SML about 0.01-0.001 microm thick, namely the sea-surface nano-layer, and also on an estimated thickness of the sampled sea-surface layer of about 100 microm, an enrichment factor of 10(5)-10(6) for the sea-surface nano-layer was calculated. Such a very high concentration increase was related to the two-fold increase of PAH concentration observed in the underlying 20 cm of the water column in late summer.


Subject(s)
Polychlorinated Biphenyls/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Seawater/analysis , Water Pollutants, Chemical/analysis , Antarctic Regions , Environmental Monitoring , Oceans and Seas , Solubility
6.
Phys Occup Ther Pediatr ; 20(4): 63-78, 2001.
Article in English | MEDLINE | ID: mdl-11382206

ABSTRACT

"Aquatic therapy" refers to therapeutic intervention taking place in water. The purpose of this review is to summarize the published articles in the rehabilitation literature from 1979 through 1999 that relate to the use of aquatic therapy as an intervention for children and adolescents with neuromuscular and musculoskeletal diagnoses. Despite the trend toward evidence-based practice, a paucity of literature exists related to aquatic therapy for children. Most of the available articles are case reports and other descriptions of clinical practice. The research reports are limited in design and scope, and subjects had a wide variety of ages and diagnoses.


Subject(s)
Exercise Therapy/methods , Hydrotherapy , Musculoskeletal Diseases/rehabilitation , Neuromuscular Diseases/rehabilitation , Pediatrics , Humans
7.
Mil Med ; 164(8): 541-2, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10459261

ABSTRACT

The rapid and unequivocal detection and identification of biological warfare agents is a major goal of military and civilian defense authorities. To identify agents of concern in an environmental sample, a reliable, region-specific characterization of the microorganisms found naturally at the sampling location is required. We have analyzed environmental air samples from Korea, Kuwait, and Bahrain by polymerase chain reaction and temporal temperature gradient electrophoresis and have produced genetic fingerprints of the natural microbial flora in these regions. Results are displayed as specific bar code patterns against which the unique patterns of potential biological warfare agents appearing in a sample can be quickly discriminated. Data are stored on compact disk, along with other laboratory analyses and relevant meteorological data, and are available to appropriate authorities and researchers.


Subject(s)
Air Microbiology , Air Pollutants/analysis , Biological Warfare/prevention & control , Environmental Monitoring/methods , Bahrain , DNA Fingerprinting , DNA, Bacterial/analysis , Databases, Factual , Humans , Korea , Kuwait , Polymerase Chain Reaction , Sampling Studies , United States
8.
Mol Gen Genet ; 260(6): 522-34, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9928931

ABSTRACT

We have isolated a mutant in fission yeast, in which mitosis is uncoupled from completion of DNA replication when DNA synthesis is impaired by a thermosensitive mutation in the gene encoding the catalytic subunit of DNA polymerase delta. By functional complementation, we cloned the wild-type gene and identified it as the recently cloned checkpoint gene crb2+/rhp9+. This gene has been implicated in the DNA damage checkpoint and acts in the Chk1 pathway. Unlike the deleted strain dcrb2, cells bearing the crb2-1 allele were not affected in the DNA repair checkpoint after UV or MMS treatment at 30 degrees C, but were defective in this checkpoint function when treated with MMS at 37 degrees C. We analysed the involvement of Crb2 in the S/M checkpoint by blocking DNA replication with hydroxyurea, by using S phase cdc mutants, or by overexpression of the mutant PCNA L68S. Both crb2 mutants were unable to maintain the S/M checkpoint at 37 degrees C. Furthermore, the crb2+ gene was required, together with the cds1+ gene, for the S/M checkpoint at 30 degrees C. Finally, both the crb2 deletion and the crb2-1 allele induced a rapid death phenotype in the poldeltats3 background at both 30 degrees C and 37 degrees C. The rapid death phenotype was independent of the checkpoint functions.


Subject(s)
Cell Cycle Proteins/genetics , DNA Polymerase III/genetics , Fungal Proteins/genetics , Mitosis/genetics , Mutation , Nuclear Proteins/genetics , Protein Serine-Threonine Kinases , S Phase/genetics , Schizosaccharomyces pombe Proteins , Schizosaccharomyces/genetics , ras-GRF1 , Cell Cycle Proteins/metabolism , Checkpoint Kinase 1 , Checkpoint Kinase 2 , DNA Damage/drug effects , DNA Damage/genetics , DNA Damage/radiation effects , DNA Replication/drug effects , DNA Replication/genetics , DNA Replication/radiation effects , Gene Deletion , Hydroxyurea/pharmacology , Mitosis/drug effects , Mitosis/radiation effects , Nuclear Proteins/metabolism , Protein Kinases/genetics , S Phase/drug effects , S Phase/radiation effects , Schizosaccharomyces/drug effects , Schizosaccharomyces/radiation effects , Temperature
9.
Biochem J ; 335 ( Pt 3): 581-8, 1998 Nov 01.
Article in English | MEDLINE | ID: mdl-9794798

ABSTRACT

We have isolated and characterized DNA polymerase delta (pol delta) from two thermosensitive Schizosaccharomyces pombe strains, poldeltats1 and poldeltats3, mutated in two different evolutionarily conserved domains of the catalytic subunit. At the restrictive temperature of 37 degreesC poldeltats1 and poldeltats3 mutant strains arrest growth in the S phase of the cell cycle. We show that at low levels of primer ends, in vitro stimulation by proliferating cell nuclear antigen (PCNA) of mutant enzymes is lower than stimulation of wild-type pol delta. Affinity for primer (3'-OH) ends and processivity of mutant enzymes do not appear different from wild-type pol delta. In contrast, Vmax values are lower than the wild-type value. The major in vitro defect appears to be decreased stimulation of mutant enzymes by PCNA, resulting in reduced velocity of DNA synthesis. In addition, ts1 pol delta is not stimulated by low PCNA concentration at 37 degreesC, although low concentrations stimulate activity at 25 degreesC, suggesting that this thermolability at low levels of primer ends could be its critical defect in vivo. Thus, both ts1 and ts3 pol delta mutations are located in regions of the catalytic subunit that seem necessary, directly or indirectly, for its efficient interaction with PCNA.


Subject(s)
DNA Polymerase III/genetics , DNA Polymerase III/metabolism , Proliferating Cell Nuclear Antigen/pharmacology , Schizosaccharomyces/enzymology , Amino Acid Sequence , Catalytic Domain , Chromatography, High Pressure Liquid , Chromatography, Ion Exchange , Conserved Sequence , DNA Polymerase III/chemistry , Enzyme Stability , Evolution, Molecular , Hot Temperature , Kinetics , Schizosaccharomyces/genetics , Templates, Genetic , Thermodynamics
10.
EMBO J ; 16(6): 1332-41, 1997 Mar 17.
Article in English | MEDLINE | ID: mdl-9135148

ABSTRACT

Fission yeast p56(chk1) kinase is known to be involved in the DNA damage checkpoint but not to be required for cell cycle arrest following exposure to the DNA replication inhibitor hydroxyurea (HU). For this reason, p56(chk1) is considered not to be necessary for the DNA replication checkpoint which acts through the inhibitory phosphorylation of p34(cdc2) kinase activity. In a search for Schizosaccharomyces pombe mutants that abolish the S phase cell cycle arrest of a thermosensitive DNA polymerase delta strain at 37 degrees C, we isolated two chk1 alleles. These alleles are proficient for the DNA damage checkpoint, but induce mitotic catastrophe in several S phase thermosensitive mutants. We show that the mitotic catastrophe correlates with a decreased level of tyrosine phosphorylation of p34(cdc2). In addition, we found that the deletion of chk1 and the chk1 alleles abolish the cell cycle arrest and induce mitotic catastrophe in cells exposed to HU, if the cells are grown at 37 degrees C. These findings suggest that chk1 is important for the maintenance of the DNA replication checkpoint in S phase thermosensitive mutants and that the p56(chk1) kinase must possess a novel function that prevents premature activation of p34(cdc2) kinase under conditions of impaired DNA replication at 37 degrees C.


Subject(s)
DNA Replication , Protein Kinases/metabolism , Schizosaccharomyces/metabolism , Checkpoint Kinase 1 , DNA Damage , DNA Replication/drug effects , DNA Replication/genetics , Hydroxyurea/pharmacology , Mutation , Phenotype , Phosphorylation , Protein Kinases/genetics , Schizosaccharomyces/drug effects , Schizosaccharomyces/genetics , Schizosaccharomyces pombe Proteins , Temperature , Tyrosine/metabolism
11.
J Biol Chem ; 270(27): 16153-9, 1995 Jul 07.
Article in English | MEDLINE | ID: mdl-7608180

ABSTRACT

ABF1 is a multifunctional phosphoprotein that binds specifically to yeast origins of replication and to transcriptional regulatory sites of a variety of genes. We isolated a protein kinase from extracts of Saccharomyces cerevisiae on the basis of its ability to specifically phosphorylate the ABF1 protein. Physical and biochemical properties of this kinase identify it as casein kinase II (CKII). The purified kinase has a high affinity for the ABF1 substrate as indicated by a relatively low Km value. Furthermore, when incubated with ABF1 and anti-ABF1 antibodies, the kinase forms an immunocomplex active in the phosphorylation of ABF1. Biochemical and genetic mapping localized a major site for phosphorylation at Ser-720 near the C terminus of the ABF1 protein. This serine is embedded within a domain enriched for acidic amino acid residues. A Ser-720 to Ala mutation abolishes phosphorylation by CKII in vitro. The same mutation also abolishes phosphorylation of this site in vivo, suggesting that CKII phosphorylates Ser-720 in vivo as well. Although three CKII enzymes, yeast, sea star, and recombinant human, utilize casein as a substrate with similar efficiencies, only the yeast enzyme efficiently phosphorylates the ABF1 protein. This suggests that ABF1 is a specific substrate of the yeast CKII and that this specificity may reside within one of the beta regulatory subunits of the enzyme. Thus, phosphorylation of ABF1 by yeast CKII may prove to be a useful system for studying targeting mechanisms of CKII to a physiological substrate.


Subject(s)
DNA-Binding Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/metabolism , Transcription Factors/metabolism , Casein Kinase II , DNA-Binding Proteins/genetics , DNA-Binding Proteins/isolation & purification , Mutation , Peptide Mapping , Phosphorylation , Protein Binding , Protein Serine-Threonine Kinases/isolation & purification , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/enzymology , Serine/genetics , Serine/metabolism , Species Specificity , Substrate Specificity , Transcription Factors/genetics , Transcription Factors/isolation & purification
12.
Mol Gen Genet ; 246(5): 561-9, 1995 Mar 10.
Article in English | MEDLINE | ID: mdl-7700230

ABSTRACT

DNA replication and DNA repair are essential cell cycle steps ensuring correct transmission of the genome. The feedback replication control system links mitosis to completion of DNA replication and partially overlaps the radiation checkpoint control. Deletion of the chk1/rad27 gene abolishes the radiation but not the replication feedback control. Thermosensitive mutations in the DNA polymerase delta, cdc18 or cdc20 genes lead cells to arrest in the S phase of the cell cycle. We show that strains carrying any of these mutations enter lethal mitosis in the absence of the radiation checkpoint chk1/rad27. We interpret these data as an indication that an assembled replisome is essential for replication dependent control of mitosis and we propose that the arrest of the cell cycle in the thermosensitive mutants is due to the chk1+/rad27+ pathway, which monitors directly DNA for signs of damage.


Subject(s)
Cell Cycle Proteins , DNA Replication/physiology , DNA-Directed DNA Polymerase/physiology , S Phase/genetics , Saccharomyces cerevisiae Proteins , Schizosaccharomyces/enzymology , Cdc20 Proteins , Checkpoint Kinase 1 , DNA Polymerase III , Feedback , Fungal Proteins/genetics , Genes, Fungal/genetics , Genes, Lethal , Mitosis , Protein Kinases/genetics , Radiation Tolerance , Schizosaccharomyces/genetics , Schizosaccharomyces/growth & development , Schizosaccharomyces pombe Proteins , Sequence Deletion/physiology , Temperature
13.
Mol Gen Genet ; 241(3-4): 457-66, 1993 Nov.
Article in English | MEDLINE | ID: mdl-8246900

ABSTRACT

The DNA polymerase alpha enzymes from human, and budding (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) are homologous proteins involved in initiation and replication of chromosomal DNA. Sequence comparison of human DNA polymerase alpha with that of S. cerevisiae and S. pombe shows overall levels of amino acid sequence identity of 32% and 34%, respectively. We report here that, despite the sequence conservation among these three enzymes, functionally active human DNA polymerase alpha fails to rescue several different conditional lethal alleles of the budding yeast POL1 gene at nonpermissive temperature. Furthermore, human DNA polymerase alpha cannot complement a null allele of budding yeast POL1 either in germinating spores or in vegetatively growing cells. In fission yeast, functionally active human DNA polymerase alpha is also unable to complement the disrupted pol alpha::ura4+ allele in germinating spores. Thus, in vivo, DNA polymerase alpha has stringent species specificity for initiation and replication of chromosomal DNA.


Subject(s)
DNA Polymerase II/metabolism , DNA Polymerase I , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/enzymology , Schizosaccharomyces/enzymology , Alleles , Amino Acid Sequence , Conserved Sequence , DNA Polymerase II/genetics , Fungal Proteins/genetics , Genetic Complementation Test , Humans , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/genetics , Schizosaccharomyces/genetics , Sequence Homology, Amino Acid , Species Specificity , Temperature
14.
Nucleic Acids Res ; 21(16): 3821-8, 1993 Aug 11.
Article in English | MEDLINE | ID: mdl-8367300

ABSTRACT

DNA polymerases alpha and delta are essential enzymes believed to play critical roles in initiation and replication of chromosome DNA. In this study, we show that the genes for Schizosaccharomyces pombe (S.pombe) DNA polymerase alpha and delta (pol alpha+ and pol delta+) are essential for cell viability. Disruption of either the pol alpha+ or pol delta+ gene results in distinct terminal phenotypes. The S.pombe pol delta+ gene is able to complement the thermosensitive cdc2-2 allele of Saccharomyces cerevisiae (S.cerevisiae) at the restrictive temperature. By random mutagenesis in vitro, we generated three pol delta conditional lethal alleles. We replaced the wild type chromosomal copy of pol delta+ gene with the mutagenized sequence and characterized the thermosensitive alleles in vivo. All three thermosensitive mutants exhibit a typical cell division cycle (cdc) terminal phenotype similar to that of the disrupted pol delta+ gene. Flow cytometric analysis showed that at the nonpermissive temperature all three mutants were arrested in S phase of the cell cycle. The three S.pombe conditional pol delta alleles were recovered and sequenced. The mutations causing the thermosensitive phenotype are missense mutations. The altered amino acid residues are uniquely conserved among the known polymerase delta sequences.


Subject(s)
DNA Polymerase II/genetics , DNA-Directed DNA Polymerase/genetics , Schizosaccharomyces/genetics , Alleles , Amino Acid Sequence , Animals , CDC2 Protein Kinase/metabolism , Cell Cycle , Cell Division/genetics , DNA Polymerase II/metabolism , DNA Polymerase III , DNA-Directed DNA Polymerase/metabolism , Flow Cytometry , Genetic Complementation Test , Humans , Molecular Sequence Data , Mutation , Phenotype , Schizosaccharomyces/enzymology , Schizosaccharomyces/growth & development , Sequence Homology, Amino Acid , Temperature
15.
Mol Biol Cell ; 4(2): 145-57, 1993 Feb.
Article in English | MEDLINE | ID: mdl-8443413

ABSTRACT

We have investigated the expression of two Schizosaccharomyces pombe replicative DNA polymerases alpha and delta during the cell cycle. The pol alpha+ and pol delta+ genes encoding DNA polymerases alpha and delta were isolated from S. pombe. Both pol alpha+ and pol delta+ genes are single copy genes in haploid cells and are essential for cell viability. In contrast to Saccharomyces cerevisiae homologs, the steady-state transcripts of both S. pombe pol alpha+ and pol delta+ genes were present throughout the cell cycle. Sequence analysis of the pol alpha+ and pol delta+ genes did not reveal the Mlu I motifs in their upstream sequences that are involved in cell cycle-dependent transcription of S. cerevisiae DNA synthesis genes as well as the S. pombe cdc22+ gene at the G1/S boundary. However, five near-match Mlu I motifs were found in the upstream region of the pol alpha+ gene. S. pombe DNA polymerases alpha and delta proteins were also expressed constantly throughout the cell cycle. In addition, the enzymatic activity of the S. pombe DNA polymerase alpha measured by in vitro assay was detected at all stages of the cell cycle. Thus, these S. pombe replicative DNA polymerases, like that of S. pombe cdc17+ gene, are expressed throughout the cell cycle at the transcriptional and protein level. These results indicate that S. pombe has at least two regulatory modes for the expression of genes involved in DNA replication and DNA precursor synthesis.


Subject(s)
Cell Cycle , DNA Polymerase II/metabolism , DNA Replication , DNA-Directed DNA Polymerase/metabolism , Gene Expression Regulation, Fungal , Schizosaccharomyces/enzymology , Base Sequence , DNA Polymerase II/genetics , DNA Polymerase II/immunology , DNA Polymerase III , DNA-Directed DNA Polymerase/genetics , DNA-Directed DNA Polymerase/immunology , Genes, Fungal , Molecular Sequence Data , Oligodeoxyribonucleotides/chemistry , Polymerase Chain Reaction , RNA, Fungal/genetics , RNA, Messenger/genetics , Restriction Mapping , Schizosaccharomyces/cytology , Schizosaccharomyces/genetics
16.
Proc Natl Acad Sci U S A ; 88(10): 4089-93, 1991 May 15.
Article in English | MEDLINE | ID: mdl-2034654

ABSTRACT

We have purified a DNA replication enhancer-binding protein, OBF1, from yeast cells grown in a medium containing 32P-labeled orthophosphate. The purified 32P-labeled protein comigrated on polyacrylamide gels with OBF1 bands identified by immunoblotting with anti-OBF1 antibodies. Furthermore, trypsin treatment of the 32P-labeled OBF1 revealed several phosphorylated peptides, suggesting that OBF1 is multiply phosphorylated in vivo. Incubation of phosphorylated peptides with calf intestinal phosphatase liberated the radiolabel as free phosphate, indicating a phosphoester linkage. Acid hydrolysis of the tryptic peptides revealed 32P-label label comigrating with phosphoserine; some of it, however, was also identified as phosphothreonine. Using anti-OBF1 antibodies, we cloned the OBF1 gene from a lambda gt11 yeast expression library. The DNA sequence of the isolated gene and its over-expression in yeast indicated that OBF1 is identical to ABF-1 and BAF1 proteins, believed to have a role in transcriptional repression and activation. Therefore, we suggest that OBF1 is a multifunctional protein, acting in transcription and replication, and that these activities are regulated by phosphorylation.


Subject(s)
DNA-Binding Proteins/metabolism , Fungal Proteins/metabolism , Phosphoserine/metabolism , Phosphothreonine/metabolism , Saccharomyces cerevisiae Proteins , Saccharomyces cerevisiae/metabolism , Transcription Factors , Amino Acid Sequence , Base Sequence , Cloning, Molecular , DNA, Fungal/genetics , Electrophoresis, Polyacrylamide Gel , Fungal Proteins/genetics , Gene Expression , Immunoblotting , Molecular Sequence Data , Peptide Fragments/metabolism , Phosphorylation , Plasmids , Trypsin
17.
Proc Natl Acad Sci U S A ; 88(9): 3877-81, 1991 May 01.
Article in English | MEDLINE | ID: mdl-2023935

ABSTRACT

To assess the role of eukaryotic DNA primase in vivo, we have produced conditional and lethal point mutations by random in vitro mutagenesis of the PR11 and PR12 genes, which encode the small and large subunits of yeast DNA primase. We replaced the wild-type copies of PRI1 and PRI2 with two pri1 and two pri2 conditional alleles. When shifted to the restrictive temperature, these strains showed altered DNA synthesis and reduced ability to synthesize high molecular weight DNA products, thus providing in vivo evidence for the essential role of DNA primase in eukaryotic DNA replication. Furthermore, mapping of the mutations at the nucleotide level has shown that the two pri1 and two pri2 conditional alleles and one pri2 lethal allele have suffered single base-pair substitutions causing a change in amino acid residues conserved in the corresponding mouse polypeptide.


Subject(s)
DNA Replication , RNA Nucleotidyltransferases/genetics , Saccharomyces cerevisiae/genetics , Alleles , Amino Acid Sequence , Base Sequence , Centrifugation, Density Gradient , DNA Mutational Analysis , DNA Primase , DNA, Fungal/biosynthesis , DNA, Fungal/chemistry , DNA, Fungal/genetics , Genes, Fungal , Molecular Sequence Data , Saccharomyces cerevisiae/growth & development
18.
Proc Natl Acad Sci U S A ; 87(12): 4665-9, 1990 Jun.
Article in English | MEDLINE | ID: mdl-2191298

ABSTRACT

We have dissected the autonomously replicating sequence ARS121 using site-directed in vitro mutagenesis. Three domains important for origin function were identified; one of these is essential and contains an 11-base-pair sequence resembling the canonical ARS core consensus; the second region, deletion of which affects the efficiency of the origin, is located 3' to the T-rich strand of the essential sequence and encompasses several elements with near matches to the ARS core consensus; the third region, containing two OBF1 DNA-binding sites and located 5' to the essential sequence, also affects the efficiency of the ARS. Here we demonstrate that a synthetic OBF1 DNA-binding site can substitute for the entire third domain in origin function. A dimer of the synthetic binding site, fused to a truncated origin containing only domains one and two, restored the origin activity to the levels of the wild-type ARS. The stimulation of origin function by the synthetic binding site was relatively orientation independent and could occur at distances as far as 1 kilobase upstream to the essential domain. Based on these results we conclude that the OBF1 DNA-binding site is an enhancer of DNA replication. We suggest that the DNA-binding site and the OBF1 protein are involved in the regulation of the activation of nuclear origins of replication in Saccharomyces cerevisiae.


Subject(s)
DNA Replication , Enhancer Elements, Genetic , Saccharomyces cerevisiae/genetics , Base Sequence , Chromosome Deletion , DNA, Fungal/genetics , Escherichia coli/genetics , Molecular Sequence Data , Mutation , Plasmids , Restriction Mapping
20.
Mol Cell Biol ; 9(7): 2906-13, 1989 Jul.
Article in English | MEDLINE | ID: mdl-2674673

ABSTRACT

We previously identified a protein activity from Saccharomyces cerevisiae, OBF1, that bound specifically to a DNA element present in autonomously replicating sequences ARS120 and ARS121 (S. Eisenberg C. Civalier, and B. K. Tye, Proc. Natl. Acad. Sci. USA 85:743-746, 1988). OBF1 has now been purified to near homogeneity by conventional protein and DNA affinity chromatography. Electrophoresis of the purified protein in sodium dodecyl sulfate-polyacrylamide gels revealed the presence of two polypeptides. The major protein band had a relative molecular size of 123 kilodaltons, and the minor protein band, which constituted only a small fraction of total protein, had a molecular size of 127 kilodaltons. Both polypeptides cochromatographed with the specific ARS120 DNA-binding activity and formed a stable protein-DNA complex, isolatable by sedimentation through sucrose gradients. Using antibodies, we have shown that both polypeptides are associated with the isolated protein-DNA complexes. The ARS DNA-binding activity had a Stokes radius of 54 A (5.4 nm) and a sedimentation coefficient of 4.28S, as determined by gel filtration and sedimentation through glycerol gradients, respectively. These physical parameters, together with the denatured molecular size values, suggested that the proteins exist in solution as asymmetric monomers. Since both polypeptides recognized identical sequences and had similar physical properties, they are probably related. In addition to binding to ARS120, we found that purified OBF1 bounds with equal affinity to ARS121 and with 5- and 10-fold-lower affinity to ARS1 and HMRE, respectively. Furthermore, in the accompanying paper (S. S. Walker, S. C. Francesconi, B. K. Tye, and S. Eisenberg, Mol. Cell. Biol. 9:2914-2921, 1989), we demonstrate the existence of a high, direct correlation between the ability of purify OBF1 to bind to ARS121 and optimal in vivo ARS121 activity as an origin of replication. These findings, taken together, suggest a role for OBF1 in ARS function, presumably at the level of initiation of DNA replication at the ARS.


Subject(s)
DNA, Fungal/metabolism , DNA-Binding Proteins/isolation & purification , Fungal Proteins/isolation & purification , Replicon , Saccharomyces cerevisiae/genetics , Binding Sites , Blotting, Western , Chromatography, Affinity , Chromatography, Gel , DNA-Binding Proteins/metabolism , Electrophoresis, Polyacrylamide Gel , Fungal Proteins/metabolism , Molecular Weight , Plasmids
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