scholarly journals Effect of hydroxyurea on mitotic activity 3H-thymidine and 3H-phenylalanine incorporation in the antheridial filament cells of Chara vulgaris

2015 ◽  
Vol 48 (2) ◽  
pp. 179-193 ◽  
Author(s):  
Anastazja Bilecka
Keyword(s):  
Protein Synthesis ◽  
Dna Replication ◽  
Helianthus Annuus ◽  
Mitotic Activity ◽  
Vicia Faba ◽  
Root Meristem ◽  
Thymidine Incorporation ◽  
Chara Vulgaris ◽  
Slowing Down ◽  
In Cells

Hydroxyurea inhibits mitotic activity in cells of the antheridial filaments of <i>Chara vulgaris</i> by blocking phase S and phase G<sub>2</sub>. Blocking of cells in phase G<sub>2</sub> also occurs in the case of the root meristem cells of <i>Helianthus annuus</i> and <i>Vicia faba</i> var. <i>minor</i>. <sup>3</sup>H-thymidine incorporation confirmed autoradiographically the blocking of cells of the antheridial filaments in <i>Chara vulgaris</i> at phase S and slowing down of the rate of DNA replication. Incubation with <sup>3</sup>H-phenylalanine demonstrated that hydroxyurea inhibits protein synthesis.

scholarly journals Changes in Epigenetic Patterns Related to DNA Replication in Vicia faba Root Meristem Cells under Cadmium-Induced Stress Conditions

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3409
Author(s):  
Aneta Żabka ◽  
Natalia Gocek ◽  
Konrad Winnicki ◽  
Paweł Szczeblewski ◽  
Tomasz Laskowski ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Dna Replication ◽  
Vicia Faba ◽  
Histone Modifications ◽  
Root Meristem ◽  
Histone H3 ◽  
S Phase ◽  
Stress Conditions ◽  
Induced Stress ◽  
Immunofluorescence Labeling

Experiments on Vicia faba root meristem cells exposed to 150 µM cadmium chloride (CdCl2) were undertaken to analyse epigenetic changes, mainly with respect to DNA replication stress. Histone modifications examined by means of immunofluorescence labeling included: (1) acetylation of histone H3 on lysine 56 (H3K56Ac), involved in transcription, S phase, and response to DNA damage during DNA biosynthesis; (2) dimethylation of histone H3 on lysine 79 (H3K79Me2), correlated with the replication initiation; (3) phosphorylation of histone H3 on threonine 45 (H3T45Ph), engaged in DNA synthesis and apoptosis. Moreover, immunostaining using specific antibodies against 5-MetC-modified DNA was used to determine the level of DNA methylation. A significant decrease in the level of H3K79Me2, noted in all phases of the CdCl2-treated interphase cell nuclei, was found to correspond with: (1) an increase in the mean number of intranuclear foci of H3K56Ac histones (observed mainly in S-phase), (2) a plethora of nuclear and nucleolar labeling patterns (combined with a general decrease in H3T45Ph), and (3) a decrease in DNA methylation. All these changes correlate well with a general viewpoint that DNA modifications and post-translational histone modifications play an important role in gene expression and plant development under cadmium-induced stress conditions.

scholarly journals Influence of aluminium chloride and sulphate on the root meristem of Vicia faba L.

2014 ◽  
Vol 52 (3-4) ◽  
pp. 185-195 ◽  
Author(s):  
Barbara Wojciechowska ◽  
Halina Kocik
Keyword(s):  
Mitotic Activity ◽  
Vicia Faba ◽  
Chromosome Aberrations ◽  
Root Meristem ◽  
Aluminium Chloride ◽  
Aluminium Sulphate ◽  
Binuclear Cells ◽  
Vicia Faba L

The influence of various (0.1, 0.05, 0.01, 0.001 and 0.0001 M) aluminium chloride and aluminium sulphate concentrations on the mitotic activity of the root meristem of the bean <em>Vicia faba</em> L. was investigated after 24 h of incubation. A mito-depressive action of the tested compounds, irreversible at higher concentrations was observed. The tested substances induced chromosome aberrations (fragmentation and bridges in anaphase or telophase, micronuclei, binuclear cells) and inhibited elongation of roots. The results of topochemical analysis are described.

Effect of medium of lowered NaCl concentration on virus release and protein synthesis in cells infected with reticuloendotheliosis virus.

1976 ◽  
Vol 17 (2) ◽  
pp. 446-452 ◽  
Author(s):  
J M Bishop ◽  
R L Maldonado ◽  
R F Garry ◽  
P T Allen ◽  
H R Bose ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Virus Release ◽  
Reticuloendotheliosis Virus ◽  
Nacl Concentration ◽  
In Cells

Altered formation of DNA replication intermediates in cells growing in different culture conditions

1989 ◽  
Vol 138 (1) ◽  
pp. 45-49
Author(s):  
Ulf lönn ◽  
Sigrid Lönn ◽  
Urban Nylen ◽  
Gerard Winblad
Keyword(s):  
Dna Replication ◽  
Culture Conditions ◽  
Replication Intermediates ◽  
In Cells

scholarly journals 40S ribosome profiling reveals distinct roles for Tma20/Tma22 (MCT-1/DENR) and Tma64 (eIF2D) in 40S subunit recycling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David J. Young ◽  
Sezen Meydan ◽  
Nicholas R. Guydosh
Keyword(s):  
Protein Synthesis ◽  
Neurological Disease ◽  
Ribosome Profiling ◽  
Minor Role ◽  
Stop Codons ◽  
Genes Encoding ◽  
Ribosome Footprinting ◽  
A Minor ◽  
And Control ◽  
In Cells

AbstractThe recycling of ribosomes at stop codons for use in further rounds of translation is critical for efficient protein synthesis. Removal of the 60S subunit is catalyzed by the ATPase Rli1 (ABCE1) while removal of the 40S is thought to require Tma64 (eIF2D), Tma20 (MCT-1), and Tma22 (DENR). However, it remains unclear how these Tma proteins cause 40S removal and control reinitiation of downstream translation. Here we used a 40S ribosome footprinting strategy to directly observe intermediate steps of ribosome recycling in cells. Deletion of the genes encoding these Tma proteins resulted in broad accumulation of unrecycled 40S subunits at stop codons, directly establishing their role in 40S recycling. Furthermore, the Tma20/Tma22 heterodimer was responsible for a majority of 40S recycling events while Tma64 played a minor role. Introduction of an autism-associated mutation into TMA22 resulted in a loss of 40S recycling activity, linking ribosome recycling and neurological disease.

scholarly journals INHIBITING EFFECT OF THE NEW CYTOTOXIC ANTIBIOTIC DAUNOMYCIN ON NUCLEIC ACIDS AND MITOTIC ACTIVITY OF HELA CELLS

1965 ◽  
Vol 27 (3) ◽  
pp. 545-550 ◽  
Author(s):  
A. Di Marco ◽  
R. Silvestrini ◽  
S. Di Marco ◽  
T. Dasdia
Keyword(s):  
Mitotic Activity ◽  
Rna Synthesis ◽  
Thymidine Incorporation ◽  
Acid Synthesis ◽  
Acetyl Derivative ◽  
Total Inhibition ◽  
Nuclear Rna ◽  
Nucleolar Rna ◽  
Higher Doses

The effect has been studied of Actinomycin D, Daunomycin (Da.), and Da. N acetyl derivative on mitotic activity and on the nucleic acid synthesis of in vitro HeLa cell cultures. The experiments were carried out by means of the radioautographic technique using stripping films. The relative uptake of thymidine-H3 and uridine-H3 was determined by means of the reduced silver grain count present in the nuclei of controls and treated cells. The mitotic activity and thymidine incorporation were noticeably reduced by Daunomycin and Actinomycin, whereas both processes appeared less affected by Da. N acetyl derivative. As regards nuclear RNA synthesis, all three antibiotics at low doses chiefly inhibit nucleolar RNA synthesis. On the other hand, whilst Actinomycin at higher doses causes an almost total inhibition of the synthesis of the whole nuclear RNA, in Daunomycin- and Da. N acetyl derivative-treated cells extranucleolar RNA synthesis is less susceptible to inhibition.

scholarly journals Stockpiling of Cdc25 during a DNA replication checkpoint arrest in Schizosaccharomyces pombe.

1996 ◽  
Vol 16 (1) ◽  
pp. 86-93 ◽  
Author(s):  
R Kovelman ◽  
P Russell
Keyword(s):  
Dna Replication ◽  
Schizosaccharomyces Pombe ◽  
Replication Checkpoint ◽  
Activation Assay ◽  
M Phase ◽  
Dna Replication Checkpoint ◽  
High Level ◽  
Tyrosyl Phosphorylation ◽  
In Cells

The DNA replication checkpoint couples the onset of mitosis with the completion of S phase. It is clear that in the fission yeast Schizosaccharomyces pombe, operation of this checkpoint requires maintenance of the inhibitory tyrosyl phosphorylation of Cdc2. Cdc25 phosphatase induces mitosis by dephosphorylating tyrosine 15 of Cdc2. In this report, Cdc25 is shown to accumulate to a very high level in cells arrested in S. This shows that mechanisms which modulate the abundance of Cdc25 are unconnected to the DNA replication checkpoint. Using a Cdc2/cyclin B activation assay, we found that Cdc25 activity increased approximately 10-fold during transit through M phase. Cdc25 was activated by phosphorylations that were dependent on Cdc2 activity in vivo. Cdc25 activation was suppressed in cells arrested in G1 and S. However, Cdc25 was more highly modified and appeared to be somewhat more active in S than in G1. This finding might be connected to the fact that progression from G1 to S increases the likelihood that constitutive Cdc25 overproduction will cause inappropriate mitosis.

scholarly journals Lethal Action of Quinolones against a Temperature-Sensitive dnaB Replication Mutant of Escherichia coli

2006 ◽  
Vol 50 (1) ◽  
pp. 362-364 ◽  
Author(s):  
Xilin Zhao ◽  
Muhammad Malik ◽  
Nymph Chan ◽  
Alex Drlica-Wagner ◽  
Jian-Ying Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Dna Replication ◽  
Nalidixic Acid ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Lethal Action ◽  
Inhibition Of Protein Synthesis

ABSTRACT Inhibition of DNA replication in an Escherichia coli dnaB-22 mutant failed to block quinolone-mediated lethality. Inhibition of protein synthesis by chloramphenicol inhibited nalidixic acid lethality and, to a lesser extent, ciprofloxacin lethality in both dnaB-22 and wild-type cells. Thus, major features of quinolone-mediated lethality do not depend on ongoing replication.

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