scholarly journals Compartmentation of uracil in Euglena gracilis.

1983 ◽  
Vol 3 (4) ◽  
pp. 613-622 ◽  
Author(s):  
C H Wasternack
Keyword(s):  
Environmental Conditions ◽  
Euglena Gracilis ◽  
Rna Synthesis ◽  
Storage Compartment ◽  
Active Pool ◽  
Tracer Kinetic ◽  
Cell Strains ◽  
Metabolic Pool ◽  
Lag Times

Compartmentation of uracil in the flagellate Euglena gracilis was studied by tracer-kinetic experiments. Lag times in the equilibration of exogenously given and intracellularly present uracil before linear labeling of catabolic and anabolic products was determined to estimate the size of its metabolically active pool. This pool operates in the incorporation and degradation of uracil. There were the same lag times in forming both final products when measured in parallel and when measured after preloading with pyrimidines, in different cell strains, and under various environmental conditions. The amount of the metabolically active uracil pool, estimated as 11 pmol/10(7) heterotrophically growing cells, decreased to almost zero during light-induced RNA synthesis and could be changed by preloading with uracil or thymine. Besides this metabolic pool, cells may contain large amounts of uracil in a membrane-enclosed storage compartment (up to 12 nmol/10(7) cells). This is metabolically inert, but may be mobilized by nitrogen-carbon starvation. The role of uracil compartmentation in this metabolically flexible organism is discussed.

Compartmentation of uracil in Euglena gracilis

1983 ◽  
Vol 3 (4) ◽  
pp. 613-622
Author(s):  
C H Wasternack
Keyword(s):  
Environmental Conditions ◽  
Euglena Gracilis ◽  
Rna Synthesis ◽  
Storage Compartment ◽  
Active Pool ◽  
Tracer Kinetic ◽  
Cell Strains ◽  
Metabolic Pool ◽  
Lag Times

Compartmentation of uracil in the flagellate Euglena gracilis was studied by tracer-kinetic experiments. Lag times in the equilibration of exogenously given and intracellularly present uracil before linear labeling of catabolic and anabolic products was determined to estimate the size of its metabolically active pool. This pool operates in the incorporation and degradation of uracil. There were the same lag times in forming both final products when measured in parallel and when measured after preloading with pyrimidines, in different cell strains, and under various environmental conditions. The amount of the metabolically active uracil pool, estimated as 11 pmol/10(7) heterotrophically growing cells, decreased to almost zero during light-induced RNA synthesis and could be changed by preloading with uracil or thymine. Besides this metabolic pool, cells may contain large amounts of uracil in a membrane-enclosed storage compartment (up to 12 nmol/10(7) cells). This is metabolically inert, but may be mobilized by nitrogen-carbon starvation. The role of uracil compartmentation in this metabolically flexible organism is discussed.

scholarly journals The role of ATP in in vitro vaccinia virus RNA synthesis effects of AMP-PNP and ATP gamma S.

1980 ◽  
Vol 255 (11) ◽  
pp. 5396-5403
Author(s):  
S. Shuman ◽  
E. Spencer ◽  
H. Furneaux ◽  
J. Hurwitz
Keyword(s):  
Vaccinia Virus ◽  
Rna Synthesis ◽  
Virus Rna ◽  
Gamma S

The Role of Vitamin B12Binding In the Uptake of the Vitamin By Euglena Gracilis

1980 ◽  
Vol 27 (2) ◽  
pp. 235-238 ◽  
Author(s):  
F. SARHAN ◽  
M. HOUDE ◽  
J. P. CHENEVAL
Keyword(s):  
Euglena Gracilis

Constitutive RNA synthesis for the yeast activator ADR1 and identification of the ADR1-5c mutation: implications in posttranslational control of ADR1

1986 ◽  
Vol 6 (11) ◽  
pp. 4026-4030
Author(s):  
C L Denis ◽  
C Gallo
Keyword(s):  
Rna Synthesis ◽  
Potential Role ◽  
Glucose Repression ◽  
Posttranslational Regulation ◽  
Mrna Levels ◽  
Recognition Sequence ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Kinase Phosphorylation

The regulation of mRNA production for the yeast positive activator ADR1, a gene required for the expression of the glucose-repressible alcohol dehydrogenase (ADH II), was studied. ADR1 mRNA levels did not vary when yeasts were switched from glucose- to ethanol-containing medium, while ADH II expression increased 100-fold. The mRNA for the ADR1-5c allele, which augments ADH II expression 60-fold during glucose repression, was not present in greater abundance than ADR1 mRNA. Additionally, the ccr1-1 allele, which blocks ADH2 mRNA formation and partially suppresses the ADR1-5c phenotype, did not alter the levels of ADR1 mRNA. These results indicate that ADR1 is not transcriptionally controlled. To determine the character of the ADR1-5c mutation, the region containing the mutation was identified and sequenced. At base pair +683 a G-to-A transition was detected in the ADR1 coding sequence which would result in the substitution of a lysine residue for an arginine at amino acid 228. The location of the ADR1-5c mutation in the interior of the ADR1 coding sequences suggests that it enhances the activity of an extant but inactive ADR1 protein rather than increases the abundance of ADR1 by altered translation of its mRNA. The ADR1-5c mutation occurs in a region of the polypeptide corresponding to a cyclic AMP-dependent protein kinase phosphorylation recognition sequence. The potential role of reversible phosphorylation in the posttranslational regulation of ADR1 is discussed.

The role of p53 in regulating genomic stability when DNA and RNA synthesis are inhibited

1995 ◽  
Vol 20 (10) ◽  
pp. 431-434 ◽  
Author(s):  
Olga B. Chernova ◽  
Michail V. Chernov ◽  
Munna L. Agarwal ◽  
William R. Taylor ◽  
George R. Stark
Keyword(s):  
Rna Synthesis ◽  
Genomic Stability ◽  
Dna And Rna ◽  
Dna And Rna Synthesis

scholarly journals Constitutive RNA synthesis for the yeast activator ADR1 and identification of the ADR1-5c mutation: implications in posttranslational control of ADR1.

1986 ◽  
Vol 6 (11) ◽  
pp. 4026-4030 ◽  
Author(s):  
C L Denis ◽  
C Gallo
Keyword(s):  
Rna Synthesis ◽  
Potential Role ◽  
Glucose Repression ◽  
Posttranslational Regulation ◽  
Mrna Levels ◽  
Recognition Sequence ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Kinase Phosphorylation

The regulation of mRNA production for the yeast positive activator ADR1, a gene required for the expression of the glucose-repressible alcohol dehydrogenase (ADH II), was studied. ADR1 mRNA levels did not vary when yeasts were switched from glucose- to ethanol-containing medium, while ADH II expression increased 100-fold. The mRNA for the ADR1-5c allele, which augments ADH II expression 60-fold during glucose repression, was not present in greater abundance than ADR1 mRNA. Additionally, the ccr1-1 allele, which blocks ADH2 mRNA formation and partially suppresses the ADR1-5c phenotype, did not alter the levels of ADR1 mRNA. These results indicate that ADR1 is not transcriptionally controlled. To determine the character of the ADR1-5c mutation, the region containing the mutation was identified and sequenced. At base pair +683 a G-to-A transition was detected in the ADR1 coding sequence which would result in the substitution of a lysine residue for an arginine at amino acid 228. The location of the ADR1-5c mutation in the interior of the ADR1 coding sequences suggests that it enhances the activity of an extant but inactive ADR1 protein rather than increases the abundance of ADR1 by altered translation of its mRNA. The ADR1-5c mutation occurs in a region of the polypeptide corresponding to a cyclic AMP-dependent protein kinase phosphorylation recognition sequence. The potential role of reversible phosphorylation in the posttranslational regulation of ADR1 is discussed.

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