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1.
World J Surg Oncol ; 18(1): 86, 2020 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-32366262

RESUMEN

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.


Asunto(s)
Carcinoma de Células Renales/cirugía , Neoplasias Colorrectales/cirugía , Neoplasias Renales/cirugía , Neoplasias Primarias Múltiples/cirugía , Nefrectomía/métodos , Proctectomía/métodos , Procedimientos Quirúrgicos Robotizados/métodos , Anastomosis Quirúrgica , Carcinoma de Células Renales/patología , Neoplasias Colorrectales/patología , Femenino , Humanos , Riñón/patología , Riñón/cirugía , Neoplasias Renales/patología , Persona de Mediana Edad , Neoplasias Primarias Múltiples/patología , Tempo Operativo , Recto/patología , Recto/cirugía , Factores de Tiempo , Resultado del Tratamiento
2.
Am J Clin Pathol ; 128(6): 926-35, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18024317

RESUMEN

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.


Asunto(s)
Técnicas de Tipificación Bacteriana , ADN Bacteriano/análisis , Francisella tularensis/genética , Tularemia/microbiología , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Animales , Electroforesis en Gel de Campo Pulsado , Francisella tularensis/clasificación , Francisella tularensis/aislamiento & purificación , Humanos , Técnicas de Diagnóstico Molecular , Ribotipificación , Espectrometría Raman/métodos
3.
Mol Cell Biol ; 9(7): 2906-13, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2674673

RESUMEN

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.


Asunto(s)
ADN de Hongos/metabolismo , Proteínas de Unión al ADN/aislamiento & purificación , Proteínas Fúngicas/aislamiento & purificación , Replicón , Saccharomyces cerevisiae/genética , Sitios de Unión , Western Blotting , Cromatografía de Afinidad , Cromatografía en Gel , Proteínas de Unión al ADN/metabolismo , Electroforesis en Gel de Poliacrilamida , Proteínas Fúngicas/metabolismo , Peso Molecular , Plásmidos
4.
Mol Cell Biol ; 9(7): 2914-21, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2674674

RESUMEN

The autonomously replicating sequence ARS121 was cloned as a 480-base-pair (bp) long DNA fragment that confers on plasmids autonomous replication in Saccharomyces cerevisiae. This fragment contains two OBF1-binding sites (sites I and II) of different affinities, as identified by a gel mobility shift assay and footprint analysis. Nucleotide substitutions (16 to 18 bp) within either of the two sites obliterated detectable in vitro OBF1 binding to the mutagenized site. Linker substitution (6 bp) mutations within the high-affinity site I showed effects similar to those of the complete substitution, whereas DNA mutagenized outside the binding site bound OBF1 normally. We also tested the mitotic stability of centromeric plasmids bearing wild-type and mutagenized copies of ARS121. Both deletion of the sites and the extensive base alterations within either of the two OBF1-binding sites reduced the percentage of plasmid-containing cells in the population from about 88% to 50 to 63% under selective growth and from about 46% to 15 to 20% after 10 to 12 generations of nonselective growth. Furthermore, linker (6 bp) substitutions within site I, the high-affinity binding site, showed similar deficiencies in plasmid stability. In contrast, plasmids containing linker substitutions in sequences contiguous to site I displayed wild-type stability. In addition, plasmid copy number analysis indicated that the instability probably resulted not from nondisjunction during mitosis but rather from inefficient plasmid replication. The results strongly support the notion that the OBF1-binding sites and the OBF1 protein are important for normal ARS function as an origin of replication.


Asunto(s)
ADN de Hongos/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas Fúngicas/metabolismo , Replicón , Saccharomyces cerevisiae/genética , Secuencia de Bases , Sitios de Unión , Clonación Molecular , Replicación del ADN , ADN de Hongos/aislamiento & purificación , Desoxirribonucleasa I , Escherichia coli/genética , Amplificación de Genes , Mutación , Plásmidos , Saccharomyces cerevisiae/metabolismo , Transformación Genética
5.
Mol Biol Cell ; 4(2): 145-57, 1993 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8443413

RESUMEN

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.


Asunto(s)
Ciclo Celular , ADN Polimerasa II/metabolismo , Replicación del ADN , ADN Polimerasa Dirigida por ADN/metabolismo , Regulación Fúngica de la Expresión Génica , Schizosaccharomyces/enzimología , Secuencia de Bases , ADN Polimerasa II/genética , ADN Polimerasa II/inmunología , ADN Polimerasa III , ADN Polimerasa Dirigida por ADN/genética , ADN Polimerasa Dirigida por ADN/inmunología , Genes Fúngicos , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos/química , Reacción en Cadena de la Polimerasa , ARN de Hongos/genética , ARN Mensajero/genética , Mapeo Restrictivo , Schizosaccharomyces/citología , Schizosaccharomyces/genética
6.
Biochim Biophys Acta ; 951(2-3): 268-73, 1988 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-3061469

RESUMEN

The yeast DNA polymerase-primase complex is composed of four polypeptides designated p180, p74, p58 and p48. All the genes coding for these polypeptides have now been cloned. By protein sequence comparison we found that yeast DNA polymerase I (alpha) shares three major regions of homology with several DNA polymerases. A fourth region, called region P, is conserved in yeast and human DNA polymerase alpha. The site of a temperature-sensitive mutation in the POL1 gene which causes decreased stability of the polymerase-primase complex has been sequenced and falls in this region. We hypothesize that region P is important for protein-protein interactions. Highly selective biochemical methods might be similarly important to distinguish functional domains in the polymerase-primase complex. An autocatalytic affinity labeling procedure has been applied to map the active center of yeast DNA primase. From this approach we conclude that both primase subunits (p48 and p58) participate in the formation of the catalytic site of the enzyme.


Asunto(s)
ARN Nucleotidiltransferasas , Saccharomyces cerevisiae/enzimología , Secuencia de Aminoácidos , Sitios de Unión , ADN Polimerasa I/genética , ADN Polimerasa II/genética , ADN Primasa , Replicación del ADN , ADN Polimerasa Dirigida por ADN/genética , Electroforesis en Gel de Poliacrilamida , Humanos , Inmunoensayo , Mutación , ARN Nucleotidiltransferasas/genética , ARN Nucleotidiltransferasas/aislamiento & purificación , ARN Nucleotidiltransferasas/metabolismo , Homología de Secuencia de Ácido Nucleico , Relación Estructura-Actividad
7.
Mil Med ; 164(8): 541-2, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10459261

RESUMEN

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.


Asunto(s)
Microbiología del Aire , Contaminantes Atmosféricos/análisis , Guerra Biológica/prevención & control , Monitoreo del Ambiente/métodos , Bahrein , Dermatoglifia del ADN , ADN Bacteriano/análisis , Bases de Datos Factuales , Humanos , Corea (Geográfico) , Kuwait , Reacción en Cadena de la Polimerasa , Muestreo , Estados Unidos
10.
Appl Environ Microbiol ; 73(22): 7465-70, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17890329

RESUMEN

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.


Asunto(s)
Francisella tularensis/genética , Eliminación de Gen , Genoma Bacteriano , Análisis por Conglomerados , ADN Bacteriano/análisis , ADN Bacteriano/genética , Electroforesis en Gel de Agar , Francia , Francisella/genética , Francisella/aislamiento & purificación , Francisella tularensis/clasificación , Francisella tularensis/aislamiento & purificación , Genes Bacterianos/genética , Reacción en Cadena de la Polimerasa , España , Especificidad de la Especie
11.
J Environ Monit ; 7(12): 1313-9, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16307089

RESUMEN

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.


Asunto(s)
Bifenilos Policlorados/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Agua de Mar/análisis , Contaminantes Químicos del Agua/análisis , Regiones Antárticas , Monitoreo del Ambiente , Océanos y Mares , Solubilidad
12.
Phys Occup Ther Pediatr ; 20(4): 63-78, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11382206

RESUMEN

"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.


Asunto(s)
Terapia por Ejercicio/métodos , Hidroterapia , Enfermedades Musculoesqueléticas/rehabilitación , Enfermedades Neuromusculares/rehabilitación , Pediatría , Humanos
13.
Proc Natl Acad Sci U S A ; 88(10): 4089-93, 1991 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-2034654

RESUMEN

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.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas Fúngicas/metabolismo , Fosfoserina/metabolismo , Fosfotreonina/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Factores de Transcripción , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN de Hongos/genética , Electroforesis en Gel de Poliacrilamida , Proteínas Fúngicas/genética , Expresión Génica , Immunoblotting , Datos de Secuencia Molecular , Fragmentos de Péptidos/metabolismo , Fosforilación , Plásmidos , Tripsina
14.
Nucleic Acids Res ; 15(19): 7975-89, 1987 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-3313275

RESUMEN

The PRI1 gene of Saccharomyces cerevisiae encodes for the p48 polypeptide of DNA primase. We have determined the nucleotide sequence of a 1,965 bp DNA fragment containing the PRI1 locus. The entire coding sequence of the gene lies within an open reading frame, and there are 409 amino acids in the single polypeptide protein if translation is assumed to start at the first ATG in this frame. The 5' and 3' end-points of PRI1 mRNA have been determined by S1 mapping and primer extension analysis. The primary structure and the codon usage of PRI1 suggest that this essential gene is poorly expressed in yeast cells.


Asunto(s)
Proteínas Fúngicas/genética , Genes Fúngicos , ARN Nucleotidiltransferasas/genética , Saccharomyces cerevisiae/genética , Secuencia de Aminoácidos , Secuencia de Bases , Codón , ADN Primasa , Genes , Datos de Secuencia Molecular , Transcripción Genética
15.
Mol Gen Genet ; 246(5): 561-9, 1995 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-7700230

RESUMEN

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.


Asunto(s)
Proteínas de Ciclo Celular , Replicación del ADN/fisiología , ADN Polimerasa Dirigida por ADN/fisiología , Fase S/genética , Proteínas de Saccharomyces cerevisiae , Schizosaccharomyces/enzimología , Proteínas Cdc20 , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , ADN Polimerasa III , Retroalimentación , Proteínas Fúngicas/genética , Genes Fúngicos/genética , Genes Letales , Mitosis , Proteínas Quinasas/genética , Tolerancia a Radiación , Schizosaccharomyces/genética , Schizosaccharomyces/crecimiento & desarrollo , Proteínas de Schizosaccharomyces pombe , Eliminación de Secuencia/fisiología , Temperatura
16.
Nucleic Acids Res ; 21(16): 3821-8, 1993 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-8367300

RESUMEN

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.


Asunto(s)
ADN Polimerasa II/genética , ADN Polimerasa Dirigida por ADN/genética , Schizosaccharomyces/genética , Alelos , Secuencia de Aminoácidos , Animales , Proteína Quinasa CDC2/metabolismo , Ciclo Celular , División Celular/genética , ADN Polimerasa II/metabolismo , ADN Polimerasa III , ADN Polimerasa Dirigida por ADN/metabolismo , Citometría de Flujo , Prueba de Complementación Genética , Humanos , Datos de Secuencia Molecular , Mutación , Fenotipo , Schizosaccharomyces/enzimología , Schizosaccharomyces/crecimiento & desarrollo , Homología de Secuencia de Aminoácido , Temperatura
17.
Mol Gen Genet ; 241(3-4): 457-66, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8246900

RESUMEN

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.


Asunto(s)
ADN Polimerasa II/metabolismo , ADN Polimerasa I , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/enzimología , Schizosaccharomyces/enzimología , Alelos , Secuencia de Aminoácidos , Secuencia Conservada , ADN Polimerasa II/genética , Proteínas Fúngicas/genética , Prueba de Complementación Genética , Humanos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Temperatura
18.
J Biol Chem ; 270(27): 16153-9, 1995 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-7608180

RESUMEN

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.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Factores de Transcripción/metabolismo , Quinasa de la Caseína II , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/aislamiento & purificación , Mutación , Mapeo Peptídico , Fosforilación , Unión Proteica , Proteínas Serina-Treonina Quinasas/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/enzimología , Serina/genética , Serina/metabolismo , Especificidad de la Especie , Especificidad por Sustrato , Factores de Transcripción/genética , Factores de Transcripción/aislamiento & purificación
19.
Proc Natl Acad Sci U S A ; 87(12): 4665-9, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2191298

RESUMEN

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.


Asunto(s)
Replicación del ADN , Elementos de Facilitación Genéticos , Saccharomyces cerevisiae/genética , Secuencia de Bases , Deleción Cromosómica , ADN de Hongos/genética , Escherichia coli/genética , Datos de Secuencia Molecular , Mutación , Plásmidos , Mapeo Restrictivo
20.
EMBO J ; 16(6): 1332-41, 1997 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-9135148

RESUMEN

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.


Asunto(s)
Replicación del ADN , Proteínas Quinasas/metabolismo , Schizosaccharomyces/metabolismo , Quinasa 1 Reguladora del Ciclo Celular (Checkpoint 1) , Daño del ADN , Replicación del ADN/efectos de los fármacos , Replicación del ADN/genética , Hidroxiurea/farmacología , Mutación , Fenotipo , Fosforilación , Proteínas Quinasas/genética , Schizosaccharomyces/efectos de los fármacos , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe , Temperatura , Tirosina/metabolismo
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