Effects of the spoT and relA Mutation on the Synthesis and Accumulation of ppGpp and RNA during Glucose Starvation

1978 ◽  
Vol 56 (4) ◽  
pp. 264-272 ◽  
Author(s):  
Gillian Chaloner-Larsson ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Synthesis ◽  
Amino Acid Starvation ◽  
Protein Accumulation ◽  
Glucose Starvation ◽  
Basal Rate ◽  
Synthetic Rate ◽  
K 12 ◽  
Stimulation Of

The effects of glucose starvation on the accumulation and synthesis of guanosine 3′,5′-bis(diphosphate) (ppGpp) were compared in four Escherichia coli K-12 strains having four different combinations of the spoT and relA alleles: spoT+relA+, spoT relA+, spoT+relA, and spoT relA. Glucose starvation caused a rapid and complete inhibition of RNA and protein accumulation and severe inhibition of RNA synthesis in all four strains. However, ppGpp accumulated only gradually in the relaxed (relA) strains and rapidly in the stringent (relA+) strains. Thus, ppGpp accumulation is not obligatory to the inhibition of RNA synthesis and accumulation during glucose starvation. During growth, relA strains synthesized ppGpp at a rate comparable with that in their relA+ partners. Glucose starvation did not affect the basal rate of ppGpp synthesis in the relA strains, but caused a transient stimulation of ppGpp synthesis in the relA+ strains. This suggests that glucose starvation causes transient amino-acid starvation. Since ppGpp accumulated in the relA strain without a change in its synthetic rate, it is inferred that ppGpp degradation decreased during glucose starvation. During growth, the turnover of ppGpp was considerably slower in the spoT strains than in the spoT+ strains. This suggests that the slower degradation of ppGpp in the spoT strains is counterbalanced by the slower synthesis of ppGpp. This difference in the rate of ppGpp synthesis became apparent when the relA strains were starved for glucose: The spoT relA strain accumulated ppGpp more slowly than did the spoT+relA strain.

scholarly journals Multi-step resistance to Chloramphenicol in RC-stringent Escherichia coli K12—its effect on the induction of RNA synthesis by antibiotics under amino acid starvation

1965 ◽  
Vol 6 (2) ◽  
pp. 304-309 ◽  
Author(s):  
E. C. R. Reeve ◽  
J. O. Bishop
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Resistant Strain ◽  
Parent Strain ◽  
Rna Synthesis ◽  
Amino Acid Starvation ◽  
Sensitive Strain ◽  
Escherichia Coli K12 ◽  
High Doses

A multi-step Chloramphenicol (CM)-resistant derivative of an RC-stringent strain of Escherichia coli auxotrophic for threonine and leucine was resistant also to Aureomycin (AM) and Puromycin (PM). All three antibiotics released the repression of RNA synthesis due to amino acid starvation in the CM-sensitive parent strain, their relative activities being about 1:10:100 for AM: CM: PM. High doses of AM and CM failed to induce RNA synthesis. The CM-resistant strain required greater concentrations of each antibiotic than the sensitive strain to induce the same level of RNA synthesis, and appeared to be about one hundred times, ten times and five times more resistant to CM, AM and PM, respectively, than the sensitive strain.

scholarly journals Synthesis of ribonucleic acid in purine-deficient Escherichia coli and a comparison with the effects of amino acid starvation

1970 ◽  
Vol 120 (1) ◽  
pp. 125-132 ◽  
Author(s):  
N. F. Varney ◽  
Gillian A. Thomas ◽  
K. Burton
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Adenine Nucleotides ◽  
Amino Acid Starvation ◽  
Guanine Nucleotides ◽  
Purine Nucleotides ◽  
Acid Control

1. Experiments with rifampicin and stringent strains of Escherichia coli (pro−purB−rel+) indicate that purine deficiency does not decrease and may considerably increase the potential for RNA synthesis by RNA polymerase molecules that are bound to DNA and have already commenced transcription. 2. DNA–RNA hybridization experiments indicate that purine starvation increases the distribution of bound RNA polymerase molecules between the cistrons for mRNA and those for stable RNA. 3. Synthesis of β-galactosidase mRNA is more dependent on the ability to synthesize guanine nucleotides than on the ability to synthesize adenine nucleotides. 4. Amino acid starvation tends to decrease the potential for RNA synthesis by RNA polymerase molecules bound to DNA. 5. Since this effect differs from that due to purine starvation, amino acid control of RNA synthesis does not appear to operate solely by causing a deficiency of purine nucleotides. 6. The results are discussed in terms of the ability to initiate RNA chains and to extend them under different circumstances.

scholarly journals Variations in resistance to three antibiotics among some single-step mutants to Chloramphenicol resistance in a strain of Escherichia coli K 12

1965 ◽  
Vol 6 (2) ◽  
pp. 310-315 ◽  
Author(s):  
E. C. R. Reeve ◽  
J. O. Bishop
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Synthesis ◽  
Single Step ◽  
Chloramphenicol Resistance ◽  
K 12

Chloramphenicol (CM), Aureomycin (AM) and Puromycin (PM) induce RNA synthesis in RC-stringent Escherichia coli starved of a required amino acid. This fact has been used to develop a method for comparing the levels of resistance of single-step CM-r mutants to the three antibiotics. Three levels of resistance to each antibiotic were found among four mutants selected in a single CM-s strain. The mutant with the highest CM resistance has the lowest AM resistance, and vice versa, while the level of PM resistance was not correlated with that of either CM or AM. The four mutants all differed from each other in their patterns of resistance to the three antibiotics.

Changes in cell dimensions during amino acid starvation of Escherichia coli

1982 ◽  
Vol 152 (1) ◽  
pp. 35-41
Author(s):  
N Grossman ◽  
E Z Ron ◽  
C L Woldringh
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Amino Acid ◽  
Microscopic Analysis ◽  
Amino Acid Starvation ◽  
Cell Diameter ◽  
Electron Microscopic ◽  
Generation Times ◽  
Cell Dimensions ◽  
K 12

Electron microscopic analysis was used to study cells of Escherichia coli B and K-12 during and after amino acid starvation. The results confirmed our previous conclusion that cell division and initiation of DNA replication occur at a smaller cell volume after amino acid starvation. Although during short starvation periods, the number of constricting cells decreased due to residual division, it appears that during prolonged starvation, cells of E. coli B and K-12 were capable of initiating new constrictions. During amino acid starvation, cell diameter decreased significantly. The decrease was reversed only after two generation times after the resumption of protein synthesis and was larger in magnitude than that previously observed before division (F. J. Trueba and C. L. Woldringh, J. Bacteriol. 142:869-878, 1980). This decrease in cell diameter correlates with synchronization of cell division which has been shown to occur after amino acid starvation.

RNA synthesis in T4 infected Escherichia coli during amino acid starvation

Virology ◽  
1972 ◽  
Vol 50 (1) ◽  
pp. 273-276 ◽  
Author(s):  
Pierluigi Donini ◽  
Gordon Edlin
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Rna Synthesis ◽  
Amino Acid Starvation

Relationship between ppGpp levels and rates of protein and RNA synthesis in Escherichia coli

1976 ◽  
Vol 54 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Gillian Chaloner-Larsson ◽  
Hiroshi Yamazaki
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Inverse Relationship ◽  
Rna Synthesis ◽  
Amino Acid Starvation ◽  
Cellular Proteins ◽  
Mrna Species ◽  
Protein And Rna Synthesis ◽  
Rna And Protein Synthesis

When amino acid starvation is ended in stringent (relA+) strains of Escherichia coli, the rates of RNA and protein synthesis as well as their accumulation return to normal more slowly in spoT− strains than in the spoT+ strains. The level of ppGpp accumulated declines more slowly in the spoT− strains than in the spoT+ strains. Thus, there is an inverse relationship between ppGpp levels and the rates of RNA and protein synthesis. The slow resumption of protein synthesis in the spoT−relA+ strains could therefore be explained in terms of the limited synthesis of mRNA species coding for the bulk of cellular proteins.

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