scholarly journals Biochemical aspects of cardiac muscle differentiation. Determination of deoxyribonucleic acid template availability and 3′-hydroxyl termini in nuclei and chromatin by using exogenous deoxyribonucleic acid polymerases

1978 ◽  
Vol 171 (2) ◽  
pp. 289-298 ◽  
Author(s):  
William C. Claycomb
Keyword(s):  
Dna Synthesis ◽  
Cardiac Muscle ◽  
Dna Polymerase ◽  
Deoxyribonucleic Acid ◽  
Dna Polymerases ◽  
Dna Polymerase Α ◽  
Dna Template ◽  
Hydroxyl Termini ◽  
Density Shift

Experiments were designed to determine whether DNA synthesis ceases in terminally differentiating cardiac muscle of the rat because the activity of the putative replicative DNA polymerase (DNA polymerase α) is lost or whether the activity of this enzyme is lost because DNA synthesis ceases. DNA-template availability and 3′-hydroxyl termini in nuclei and chromatin, isolated from cardiac muscle at various times during the developmental period in which DNA synthesis and the activity of DNA polymerase α are decreasing, were measured by using Escherichia coli DNA polymerase I, Micrococcus luteus DNA polymerase and DNA polymerase α under optimal conditions. Density-shift experiments with bromodeoxyuridine triphosphate and isopycnic analysis indicate that DNA chains being replicated semi-conservatively in vivo continue to be elongated in isolated nuclei by exogenous DNA polymerases. DNA template and 3′-hydroxyl termini available to exogenously added DNA polymerases do not change as cardiac muscle differentiates and the rate of DNA synthesis decreases and ceases in vivo. Template availability and 3′-hydroxyl termini are also not changed in nuclei isolated from cardiac muscle in which DNA synthesis had been inhibited by administration of isoproterenol and theophylline to newborn rats. DNA-template availability and 3′-hydroxyl termini, however, were substantially increased in nuclei and chromatin from cardiac muscle of adult rats. This increase is not due to elevated deoxyribonuclease activity in nuclei and chromatin of the adult. Electron microscopy indicates that this increase is also not due to dispersal of the chromatin or disruption of nuclear morphology. Density-shift experiments and isopycnic analysis of DNA from cardiac muscle of the adult show that it is more fragmented than DNA from cardiac-muscle cells that are, or have recently ceased, dividing. These studies indicate that DNA synthesis ceases in terminally differentiating cardiac muscle because the activity of a replicative DNA polymerase is lost, rather than the activity of this enzyme being lost because DNA synthesis ceases.

scholarly journals Palm Mutants in DNA Polymerases α and η Alter DNA Replication Fidelity and Translesion Activity

2004 ◽  
Vol 24 (7) ◽  
pp. 2734-2746 ◽  
Author(s):  
Atsuko Niimi ◽  
Siripan Limsirichaikul ◽  
Shonen Yoshida ◽  
Shigenori Iwai ◽  
Chikahide Masutani ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Dna Polymerases ◽  
Pyrimidine Dimer ◽  
Replication Fidelity ◽  
Dna Polymerase Α ◽  
Replication Errors ◽  
Translesion Dna

ABSTRACT We isolated active mutants in Saccharomyces cerevisiae DNA polymerase α that were associated with a defect in error discrimination. Among them, L868F DNA polymerase α has a spontaneous error frequency of 3 in 100 nucleotides and 570-fold lower replication fidelity than wild-type (WT) polymerase α. In vivo, mutant DNA polymerases confer a mutator phenotype and are synergistic with msh2 or msh6, suggesting that DNA polymerase α-dependent replication errors are recognized and repaired by mismatch repair. In vitro, L868F DNA polymerase α catalyzes efficient bypass of a cis-syn cyclobutane pyrimidine dimer, extending the 3′ T 26,000-fold more efficiently than the WT. Phe34 is equivalent to residue Leu868 in translesion DNA polymerase η, and the F34L mutant of S. cerevisiae DNA polymerase η has reduced translesion DNA synthesis activity in vitro. These data suggest that high-fidelity DNA synthesis by DNA polymerase α is required for genomic stability in yeast. The data also suggest that the phenylalanine and leucine residues in translesion and replicative DNA polymerases, respectively, might have played a role in the functional evolution of these enzyme classes.

scholarly journals Poly(adenosine diphosphate ribose) polymerase activity and nicotinamide adenine dinucleotide in differentiating cardiac muscle

1976 ◽  
Vol 154 (2) ◽  
pp. 387-393 ◽  
Author(s):  
W C. Claycomb
Keyword(s):  
Cyclic Amp ◽  
Dna Synthesis ◽  
Cardiac Muscle ◽  
Dna Polymerase ◽  
Specific Activity ◽  
Polymerase Activity ◽  
Neonatal Rat ◽  
Dibutyryl Cyclic Amp ◽  
Fresh Tissue ◽  
Dna Polymerase Α

Poly(ADP-ribose) polymerase activity in nuclei isolated from differentiating cardiac muscle of the rat has been characterized and its activity measured during development. Optimum enzyme activity is observed at pH 8.5. Poly(ADP-ribose) polymerase is inhibited by ATP, thymidine, nicotinamide, theophylline, 3-isobutyl-1-methylxanthine and caffeine and stimulated by actinomycin D. The activity measured under optimal assay conditions increases during differentiation of cardiac muscle and is inversely related to the rate of DNA synthesis and to the activities of DNA polymerase α and thymidine kinase. When DNA synthesis and the activity of DNA polymerase α are inhibited in cardiac muscle of the 1-day-old neonatal rat by dibutyryl cyclic AMP or isoproterenol, the specific activity of poly(ADP-ribose) polymerase measured in isolated nuclei is increased. The concentration of NAD+ in cardiac muscle increases during postnatal development. In the adult compared with the 1-day-old neonatal rat the concentration of NAD+ relative to fresh tissue weight, DNA or protein increased 1.7-fold, 5.2-fold or 1.4-fold respectively. The concentration of NAD+ in cardiac muscle of the 1-day-old neonatal rat can be increased by approx. 20% by dibutyryl cyclic AMP. These data suggest that NAD+ and poly(ADP-ribose) polymerase may be involved with the repression of DNA synthesis and cell proliferation in differentiating cardiac muscle.

Tokishakuyakusan Effect on DNA Polymerase α Activity in Relationship to DNA Synthesis before and/or after the LH/FSH Surge in Rats

1995 ◽  
Vol 23 (03n04) ◽  
pp. 231-242 ◽  
Author(s):  
Satoshi Usuki ◽  
Eri Kotani ◽  
Yumiko Kawakura ◽  
Masaki Sano ◽  
Yukitaka Katsura ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Estrous Cycle ◽  
Dna Polymerase ◽  
Preovulatory Follicle ◽  
Dna Polymerase Β ◽  
Dna Polymerase Α ◽  
Immature Rats ◽  
Α Activity

DNA polymerase α activity in ovaries of mature cycling rats during the normal estrous cycle changed in a cyclic manner with a peak at 1800 h in proestrus. Tokishakuyakusan (TS) in vivo did not affect the changes in DNA polymerase α and β activities during the estrous cycle. LH and FSH at 1000 or 1700 h in proestrus increased DNA polymerase α activity, but the DNA polymerase α activity induced by LH or FSH was not significantly affected by the addition of TS. DNA polymerase β activity did not change with LH, FSH or TS. In PMS-treated or -untreated immature rats, TS enhanced ovarian DNA polymerase α activity but had no significant effect on LH or FSH action. In ovaries, incubated in vitro, in untreated mature or immature rats, TS enhanced ovarian DNA polymerase α activity but had no significant effect on LH or FSH action. These results suggest that TS stimulates ovarian DNA polymerase α activity in relationship to DNA synthesis and does not affect the effect of LH or FSH on the activity by preovulatory follicle before and/or after the LH/FSH surge.

scholarly journals Mechanism for priming DNA synthesis by yeast DNA Polymerase α

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Rajika L Perera ◽  
Rubben Torella ◽  
Sebastian Klinge ◽  
Mairi L Kilkenny ◽  
Joseph D Maman ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Catalytic Core ◽  
Dna Polymerase Α ◽  
Dna Oligonucleotides ◽  
Computational Data ◽  
Dna Template ◽  
Lagging Strand ◽  
Primase Complex ◽  
Nucleotide Polymerization

The DNA Polymerase α (Pol α)/primase complex initiates DNA synthesis in eukaryotic replication. In the complex, Pol α and primase cooperate in the production of RNA-DNA oligonucleotides that prime synthesis of new DNA. Here we report crystal structures of the catalytic core of yeast Pol α in unliganded form, bound to an RNA primer/DNA template and extending an RNA primer with deoxynucleotides. We combine the structural analysis with biochemical and computational data to demonstrate that Pol α specifically recognizes the A-form RNA/DNA helix and that the ensuing synthesis of B-form DNA terminates primer synthesis. The spontaneous release of the completed RNA-DNA primer by the Pol α/primase complex simplifies current models of primer transfer to leading- and lagging strand polymerases. The proposed mechanism of nucleotide polymerization by Pol α might contribute to genomic stability by limiting the amount of inaccurate DNA to be corrected at the start of each Okazaki fragment.

Effects of Tokishakuyakusan, Keishibukuryogan and Unkeito on DNA Polymerase α Activity in Uteri of Pregnant Mare's Serum Gonadotropin-treated Immature Rats

1992 ◽  
Vol 20 (01) ◽  
pp. 75-82 ◽  
Author(s):  
Satoshi Usuki
Keyword(s):  
Dna Polymerase ◽  
Deoxyribonucleic Acid ◽  
Herbal Medicines ◽  
Concomitant Treatment ◽  
Remarkable Effect ◽  
Dna Polymerase Α ◽  
Blood Injection ◽  
Serum Gonadotropin ◽  
Α Activity

To provide some insights how herbal medicines affect deoxyribonucleic acid (DNA) synthesis in the uterus, the DNA polymerase activities (α and β) in uterine samples taken from rats were measured. DNA polymerase α activity with respect to DNA content revealed α cyclic change with the highest level on proestrus, while DNA polymerase β activity showed no significant changes during the estrous cycle. The increased period of the activity coincided with that of l7β-estradiol ( E 2) but not progesterone ( P 4) in the blood. Injection of 10 IU pregnant mare serum gonadotropin (PMS) on day 27 of age gradually increased DNA polymerase α activity in uteri, while concomitant treatment with PMS and 200 μg Tokishakuyakusan (TS), Keishibukuryogan (KB) or Unkeito (UT) suppressed the enzyme activity, with a most remarkable effect of KB. These results suggest that TS, KB or UT suppresses in vivo DNA polymerase α activity induced by PMS in the rat uterus.

PrimPol (Primase/Polymerase), replicating enzyme – A mini review

2020 ◽  
Vol 2 (4) ◽  
pp. 89-92
Author(s):  
Muhammad Amir ◽  
Sabeera Afzal ◽  
Alia Ishaq
Keyword(s):  
Dna Replication ◽  
Dna Polymerase ◽  
Genetic Information ◽  
Nuclear Dna ◽  
De Novo ◽  
Dna Polymerases ◽  
Test Site ◽  
Mitochondrial Dna Replication ◽  
Dna Template ◽  
Preliminary Phase

Polymerases were revealed first in 1970s. Most important to the modest perception the enzyme responsible for nuclear DNA replication that was pol , for DNA repair pol and for mitochondrial DNA replication pol  DNA construction and renovation done by DNA polymerases, so directing both the constancy and discrepancy of genetic information. Replication of genome initiate with DNA template-dependent fusion of small primers of RNA. This preliminary phase in replication of DNA demarcated as de novo primer synthesis which is catalyzed by specified polymerases known as primases. Sixteen diverse DNA-synthesizing enzymes about human perspective are devoted to replication, reparation, mutilation lenience, and inconsistency of nuclear DNA. But in dissimilarity, merely one DNA polymerase has been called in mitochondria. It has been suggest that PrimPol is extremely acting the roles by re-priming DNA replication in mitochondria to permit an effective and appropriate way replication to be accomplished. Investigations from a numeral of test site have significantly amplified our appreciative of the role, recruitment and regulation of the enzyme during DNA replication. Though, we are simply just start to increase in value the versatile roles that play PrimPol in eukaryote.

scholarly journals Involvement of deoxyribonucleic acid polymerase β in nuclear deoxyribonucleic acid synthesis

1978 ◽  
Vol 173 (1) ◽  
pp. 309-314 ◽  
Author(s):  
T R Butt ◽  
W M Wood ◽  
E L McKay ◽  
R L P Adams
Keyword(s):  
Dna Synthesis ◽  
Dna Polymerase ◽  
Deoxyribonucleic Acid ◽  
Nuclear Dna ◽  
Dna Polymerase Beta ◽  
Cell Nuclei ◽  
High Molecular Weight Dna ◽  
Dna Polymerase Alpha ◽  
Polymerase Beta

The effects on DNA synthesis in vitro in mouse L929-cell nuclei of differential extraction of DNA polymerases alpha and beta were studied. Removal of all measurable DNA polymerase alpha and 20% of DNA polymerase beta leads to a 40% fall in the replicative DNA synthesis. Removal of 70% of DNA polymerase beta inhibits replicative synthesis by 80%. In all cases the nuclear DNA synthesis is sensitive to N-ethylmaleimide and aCTP (arabinosylcytosine triphosphate), though less so than DNA polymerase alpha. Addition of deoxyribonuclease I to the nuclear incubation leads to synthesis of high-molecular-weight DNA in a repair reaction. This occurs equally in nuclei from non-growing or S-phase cells. The former nuclei lack DNA polymerase alpha and the reaction reflects the sensitivity of DNA polymerase beta to inhibiton by N-ethylmaleimide and aCTP.

The Mechanism of Replication of Single-Stranded DNA. VI. Requirements for Ribonucleoside Triphosphates and DNA Polymerase III

1973 ◽  
Vol 51 (12) ◽  
pp. 1588-1597 ◽  
Author(s):  
David T. Denhardt ◽  
Makoto Iwaya ◽  
Grant McFadden ◽  
Gerald Schochetman
Keyword(s):  
Dna Polymerase ◽  
Dna Polymerases ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Dna Polymerase Iii ◽  
Single Stranded Dna ◽  
E Coli ◽  
Polymerase Iii

Evidence is presented that in Escherichia coli made permeable to nucleotides by exposure to toluene, the synthesis of a DNA chain complementary to the infecting single-stranded DNA of bacteriophage [Formula: see text] requires ATP as well as the four deoxyribonucleoside triphosphates. This synthesis results in the formation of the parental double-stranded replicative-form (RF) molecule. The ATP is not required simply to prevent degradation of the ribonucleoside or deoxyribonucleoside triphosphates; it can be partially substituted for by other ribonucleoside triphosphates.No single one of the known E. coli DNA polymerases appears to be uniquely responsible in vivo for the formation of the parental RF. Since [Formula: see text] replicates well in strains lacking all, or almost all, of the in-vitro activities of DNA polymerases I and II, neither of these two enzymes would seem essential; and in a temperature-sensitive E. coli mutant (dnaEts) deficient in DNA polmerase-I activity and possessing a temperature-sensitive DNA polymerase III, the viral single-stranded DNA is efficiently incorporated into an RF molecule at the restrictive temperature. In contrast, both RF replication and progeny single-stranded DNA synthesis are dependent upon DNA polymerase III activity.

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