Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A mutant of Bacillus subtilis which grew in complex medium at 30 degrees C but lysed at 45 degrees C has been isolated. It could only grow on minimal medium at 45 degrees C with added aspartate (20 microgram ml-1) but lysed if lysine (20 microgram ml-1) was also present. The requirement for aspartate was due to a low activity of pyruvate carboxylase; the site of the mutation (pyc) was linked (16% cotransducible using phage PBSI) to the pyrD locus, and the order of markers deduced was: pyrD-cysC-pyc. This defect appeared to lead to decreased synthesis of mesodiaminopimelic acid (mesoA2pm), an amino acid unique to peptidoglycan and its precursors. At the restrictive temperature the mutant accumulated uridine-5'-diphosphate N-acetylmuramyl-L-alanyl-D-glutamate, since meso A2pm is the next amino acid to be added to the growing peptide chain of peptidoglycan. This resulted in an inhibition of peptidoglycan synthesis, determined as a reduced incorporation of N-acetyl[14C]glucosamine. Peptidoglycan synthesis was not decreased if the mutant was grown in media containing aspartate but lacking lysine. The sensitivity to lysine may arise because (i) at 45 degrees C the mutant was starved for aspartate and hence mesoA2pm even when aspartate was present, since aspartate utilization, as estimated by the incorporation of [3H]aspartate into trichloroacetic acid precipitable material, was relatively inefficient; and (ii) this diminished level of mesoA2pm synthesis from aspartate was further curtailed since lysine inhibits one of the aspartokinases in B. subtilis. Thus, addition of lysine allowed protein synthesis and hence autolysin production to proceed whilst peptidoglycan synthesis remained inhibited. When autolysis was blocked, either indirectly by stopping protein synthesis through starvation of aspartate and lysine, or directly by introducing a lyt mutation, then shifting the mutant to 45 degrees C did not result in lysis but growth still ceased.
J Gen Microbiol 1978 Apr
PMID:A heat-sensitive lysis mutant of Bacillus subtilis 168 with a low activity of pyruvate carboxylase. 41 47

The mating reaction in Tetrahymena thermophila includes a starvation period and two distinct cell interactions, co-stimulation and cell pairing, before the cells are cytoplasmically joined as conjugants. A selection procedure for harvesting mutants unable to mate at a restrictive temperature has been developed. A conjugant pair consisting of one cycloheximide-resistant cell and one wild-type cell (cycloheximide-sensitive) was itself sensitive to the drug. By adding cycloheximide and nutrient medium to a cross made at the restrictive and grow. Repetition of the selection procedure enriched for cells unable to conjugate at the restrictive temperature. The selected cells were able to grow at 38 degrees C and could conjugate at 28 degrees C. This procedure may be narrowed to select specifically for cell interaction mutants.
J Gen Microbiol 1979 Dec
PMID:Mass selection of conditional mating mutants of Tetrahymena thermophila. 52 76

The haploid myxamoebae of Physarum polycephalum reversibly differentiate to form dormant microcysts under conditions of starvation. The thin-walled cysts can be selective recovered from a cell suspension which has been treated with the surfactant Triton X-100 to lyse amoeboid forms. Excystment, which is initiated by suspension in liquid medium, is inhibited by antibiotics which block protein synthesis. Cysts of drug resistant mutants excyst rapidly in media containing sufficient antibiotic to maintain drug sensitive strains in the encysted state. The selective survival of non-excysted cells following Triton X-100 treatment has been employed to enrich for drug sensitive mutants. Several anisomycin sensitive mutants have been isolated, one of which has been analysed genetically. The possible applications of this mutant enrichment technique are discussed.
Mol Gen Genet 1977 Mar 16
PMID:Anisomycin sensitive mutants of Physarum polycephalum isolated by cyst selection. 55 41

The effects of potentially perturbating influences on the respiration of glucose-grown Candida utilis were studied using an open oxygen electrode system. Periods of anaerobiosis as short as 2 min produced an oscillation in respiration after the air supply was restored. Longer exposure to anoxia was followed by an overshoot in dissolved oxygen after switching back to a gas phase of air. Centrifugation, cold shock or nutrient starvation caused less disturbance to respiration rates than did anaerobiosis. The high frequency oscillations (period about 5 min) resulting from anaerobic-aerobic transitions are contrasted with the slow cell cycle-dependent oscillations previously observed in synchronous cultures.
J Gen Microbiol 1979 Oct
PMID:Perturbation of respiration in Candida utilis: induction of metabolic oscillations. 57 46

The absence from the medium of any of the 13 amino acids essential for cell growth has an inhibiting effect on the multiplication of adenovirus 9-15 and adenovirus I in HeLa cell cultures. The inhibition is accentuated by previous amino acid starvation of the cultures. Whereas with arginine deprivation, the arginine pool inside the cells is at a minimum within 30 min, the cells are assumed to adapt slowly to the new metabolic state, which is characterized by an increased 'turnover' of protein synthesis. With arginine deficiency and in Hanks' BSS some synthesis of virus and capsid proteins takes place. Quantitative and possibly qualitative differences between the influence of the various deficient media were observed. The experiments rule out DNA synthesis as a primary cause of the amino acid deficiency effect. They lead to the hypothesis that arginine deficiency inhibits the formation of an essential protein which is synthesized very late in the infectious cycle under complete MEM.
J Gen Virol 1978 May
PMID:Amino acid requirement of adenovirus multiplication. 65 Jan 77

An isogenic pair of Escherichia coli strains, one carrying an rnc+ and the other an rnc- allele (a mutation which reduces the level of ribonuclease III), was compared. The rnc- strain fails to grow at very elevated temperatures (for E. coli) while the rnc+ strain does grow exponentially. Assaying the residual RNase III like activity in extracts of the rnc- strain at different pHs and at different temperatures suggested that this residual RNase III like activity is not due to RNase III. This raised the possibility that the rnc- strain is devoid of any RNase III activity in the cell. Comparing the decay of newly synthesized RNA and functional decay of beta-galactosidase mRNA in such strains revealed that in both strains these parameters proceed in similar rates, which suggests that RNase III is not involved in the metabolism of mRNA. During carbon starvation preexisting total RNA, as well as 23S and 16S rRNA, decay faster in the rnc- strain, thus eliminating the possibility that RNase III is the endoribonuclease which initiates the decay of rRNA during starvation (Kaplan and Apirion, 1975a).
Mol Gen Genet 1976 Mar 22
PMID:Consequences of losing ribonuclease III on the Escherichia coli cell. 77 91

When growing cultures of S. cerevisiae are treated with high concentrations of ethidium bromide (greater than 50 mug/ml), three phases of petite induction may be observed: I. the majority of cells are rapidly converted to petite, II. subsequently a large proportion of cells recover the ability to form respiratory competent clones, and III. slow, irreversible conversion of all cells to petite. The extent of recovery of respiratory competence observed is dependent on the strain of S. cerevisiae employed and the temperature and the carbon source used in the growth medium. The effects of 100 mug/ml ethidium bromide are also produced by 10 mug/ml ethidium bromide in the presence of the detergent, sodium dodecyl sulphate, and recovery is also observed when cells are treated with 10 mug/ml ethidium bromide under starvation conditions. Genetic analysis of strain differences indicates that a number of nuclear genes influence petite induction by ethidium bromide. In one strain, S288C, petite induction by 100 mug/ml ethidium bromide is extremely slow under certain conditions. Mitochondria isolated from from S288C lack the ethidium bromide stimulated nuclease activity found in D243-4A, a strain which shows triphasic kinetics of petite formation. This enzyme may, therefore, be responsible for the initial phase of rapid petite formation.
Mol Gen Genet 1976 Mar 30
PMID:Factors affecting petite induction and the recovery of respiratory competence in yeast cells exposed to ethidium bromide. 77 97

Strand breaks accumulated in the DNA of a temperature-sensitive DNA ligase mutant of Escherichia coli growing at the restrictive temperature, as detected by zone sedimentation through alkaline sucrose density gradients. The rate of strand breakage was increased by concomitant thymine starvation. Rifampicin and chloramphenicol inhibited the accumulation of strand breaks in the DNA. There was a correlation between the accumulation of strand breaks in the DNA and lethality, suggesting that such breaks are the basis for lethality at the restrictive temperature.
J Gen Microbiol 1976 Jun
PMID:Properties of a DNA ligase mutant of Escherichia coli: introduction of strand breaks in DNA. 78 Nov 80

A temperature sensitive mutant of Escherichia coli which fails to recover from prolonged carbon starvation, was found to be irreversibly killed by exposure to a nonpermissive temperature (43 degrees C), with a half-life of about half an hour. This bacteriocidal effect of the temperature could be reversed by a number of antibiotics which block protein synthesis but not by blocking DNA synthesis. At the nonpermissive temperature, RNA and the protein synthetic capacities decrease before the DNA synthetic capacity is decreased. Analysis of ribosomal proteins and methylation of them did not reveal any consistent differences between the parental and mutant strains. Analysis of the ribosomal RNA revealed that it is being synthesized in similar amounts as in the parental strain at the nonpermissive temperature, however, after chase its level is decreased. Moreover, the 17S precursor RNA is slow to mature to 16S rRNA in the mutant strain at the nonpermissive temperature. Thus, these studies suggest that the mutation studied here affects a late maturation step in the synthesis of the rRNA. Therefore the gene is designated rimH (for ribosomal modification). All the properties bestowee on the mutant strain are caused by a single pleiotropic mutation which maps at min 14 of the E. coli map. Three point transduction crosses suggest the order rimH, leuS, RNA, LIP. This gene maps outside the two known clusters for ribosomal structural genes.
Mol Gen Genet 1976 Aug 10
PMID:A lethal mutation which affects the maturation of ribosomes. 78 23

Escherichia coli K12 Hfr H Tsxs Strs and F- Pro- Tsxr His- Arg- Strr bacteria were conjugated in the absence of arginine with or without glucose. The efficiency of conjugation, measured by the frequency of Pro+ and His+ recombinants was not affected. Arginine starvation alone did not affect the tsxs gene expression which occurred in all the zygotes which had received the gene. In contrast, argine and glucose starvation allows tsxs expression only in those zygotes in which the donor gene had been integrated in the genome. As the glucose starvation brings on a destabilization of the messenger RNA synthesized by the F- cells in absence of arginine, the results can be interpreted as follows: the transferred tsxs genes are transitorily expressed in all the zygotes at the unintegrated state. After this transient period, only thsoe genes integrated in the chromosomes of the zygotes continue to be expressed.
Mol Gen Genet 1976 Aug 10
PMID:Effect of glucose starvation on the expression of transferred tsx genes in Escherichia coli K12 zygotes. 78 25


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