Polyamine Limitation of Growth Slows the Rate of Polypeptide Chain Elongation in
            <i>Escherichia coli</i>

Jorstad, Caroline M.; Morris, David R.

doi:10.1128/jb.119.3.857-860.1974

Cited by 17 publications

(8 citation statements)

References 12 publications

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“…Polyamines have been shown to influence the fidelity of protein synthesis and to be required in some cases for the action of nonsense suppressor mutations in bacteria (1, 11,12,24,25). Our data show that nonsense suppression is qualitatively successful in N. crassa despite severe polyamine starvation in our suppressed mutants.…”

Section: Ic-1474 (Pe4)mentioning

confidence: 52%

Nonsense Mutations of the Ornithine Decarboxylase Structural Gene of Neurospora crassa

Davis

Hynes

Eversole-Cire

1987

Molecular and Cellular Biology

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Ornithine decarboxylase (ODC) (EC 4.1.1.17) is an early enzyme of polyamine synthesis, and its activity rises quickly at the onset of growth and differentiation in most eucaryotes. Some have speculated that the enzyme protein may have a role in the synthesis of rRNA in addition to its role in catalyzing the decarboxylation of ornithine (G. D. Kuehn and V. J. Atmar, Fed. Proc. 41:3078-3083, 1982; D. H. Russell, Proc. Natl. Acad. Sci. USA 80:1318-1321, 1983). To test this possibility, we sought mutational evidence for the indispensability of the ODC protein for normal growth of Neurospora crassa. We found three new, ODC-deficient mutants that lacked ODC protein. Among these and by reversion analysis of an earlier set of mutants, we found that two ODC-deficient mutants carried nonsense mutations in the ODC structural gene, spe-1. Allele LV10 imparted a complete deficiency for enzyme activity (less than 0.006% of normal) and had no detectable ODC antigen. Allele PE4 imparted a weak activity to cells (0.1% of derepressed spe+ cultures) and encoded a lower-molecular-weight ODC subunit (Mr = 43,000) in comparison to that of the wild-type strain (Mr = 53,000). Strains carrying either mutation, like other spe-1 mutants, grew at a normal rate in exponential culture if the medium was supplemented with spermidine, the main end product of the polyamine pathway in N. crassa. Unless an antigenically silent, N-terminal fragment with an indispensable role persists in the LV10-bearing mutant, we conclude that the ODC protein has no role in the vegetative growth of this organism other than the synthesis of polyamines. The data extend earlier evidence that spe-1 is the structural gene for ODC in N. crassa. The activity found in mutants bearing allele PE4 suggests that the amino acids nearest the carboxy terminus do not contribute to the active site of the enzyme.

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Section: Ic-1474 (Pe4)mentioning

confidence: 52%

Nonsense Mutations of the Ornithine Decarboxylase Structural Gene of Neurospora crassa

Davis

Hynes

Eversole-Cire

1987

Molecular and Cellular Biology

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“…Starvation for polyamines reduced the growth rate of the mutant cells and produced an identical reduction in the rates of RNA and protein syntheses (14). Inhibition of RNA and protein syntheses was due to decreased polymerization rates rather than to specific effects only on initiation (9,15). The rate of DNA replication fork movement was also slowed during polyamine deficiency (6).…”

Section: Nh2+(ch2)3nh3+mentioning

confidence: 97%

Structural specificity of the spermidine requirement of an Escherichia coli auxotroph

Jorstad¹,

Harada²,

Morris³

1980

J Bacteriol

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A homologous series of spermidine analogs was synthesized with the general structure NH3+(CH2),NH2+(CH2)3NH3+, where spermidine has n = 4. The influence ofthese compounds on growth and on the syntheses of protein and messenger ribonucleic acid was examined in a spermidine auxotroph of Escherichia coli. All of the homologs tested were taken up by the cells to an intracellular level equivalent to the level of spermidine which gives optimal growth. With increasing chain length of the homologs, there was reduced ability to stimulate growth. The homologs with n = 7 and n = 8 were essentially inactive. A similar specificity was observed when the ability of the homologs to restore the rates of protein and messenger ribonucleic acid chain elongation was compared to that of spermidine. These results suggest that a definite spatial arrangement of the amino groups of spermidine is required for productive interaction at its intracellular site(s) of action.Wild-type Escherichia coli growing in minimal medium contains milimolar intracellular concentrations of spermidine [NH3+(CH2)4-

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“…Experiments from this laboratory, using steady-state, polyamine-limited E. coli, have shown that these cells have defects in three classes of macromolecular synthesis. The chain elongation rates for protein (10,18), mRNA (18), and DNA (6) are all reduced in proportion to the reduction in growth rate. This is an unusual response, in that cells normally respond to a decreased growth rate by reducing the frequenccy of initiation of new chains and not by altering the chain growth rate.…”

mentioning

confidence: 99%

Stimulation of deoxyribonucleic acid replication fork movement by spermidine analogs in polyamine-deficient Escherichia coli

Geiger¹,

Morris²

1980

J Bacteriol

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We examined the rate of deoxyribonucleic acid (DNA) replication fork movement in polyamine-deficient cells of Escherichia coli by two independent techniques. DNA autoradiography was used to directly visualize the length of DNA produced during a given time interval, and replication rates were calculated. The amount of DNA synthesized after blocking protein synthesis also allowed calculation of replication rates. We found that the DNA chain elongation rate in polyamine-deficient cells was about half that of putrescine- or spermidine-supplemented cells. We also found that spermidine homologs of increasing chain length, when present at equal intracellular concentrations, exhibited a decreasing ability to support growth and the rate of DNA replication fork movement. The kinetics of recovery of DNA synthesis from the polyamine-deficient state were also investigated. A new rate of DNA synthesis was reached about 20 min after addition of spermidine to polyamine-limited cells. The rise in the rate of DNA synthesis was preceded by a rise in the intracellular concentration of spermidine.

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Polyamine Limitation of Growth Slows the Rate of Polypeptide Chain Elongation in Escherichia coli

Cited by 17 publications

References 12 publications

Nonsense Mutations of the Ornithine Decarboxylase Structural Gene of Neurospora crassa

Nonsense Mutations of the Ornithine Decarboxylase Structural Gene of Neurospora crassa

Structural specificity of the spermidine requirement of an Escherichia coli auxotroph

Stimulation of deoxyribonucleic acid replication fork movement by spermidine analogs in polyamine-deficient Escherichia coli

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