Gene yddG of Escherichia coli encoding the putative exporter of aromatic amino acids: Constitutive transcription and dependence of the expression on the cell growth rate

2009 ◽  
Vol 45 (5) ◽  
pp. 525-532 ◽  
Author(s):  
I. S. Tsyrenzhapova ◽  
V. G. Doroshenko ◽  
L. G. Airich ◽  
A. S. Mironov ◽  
S. V. Mashko
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Growth Rate ◽  
Cell Growth ◽  
Aromatic Amino Acids ◽  
Cell Growth Rate

82 Methyl Donor Supplementation Alters Cytosine Methylation and Biological Processes of Cells Cultured in Divergent Glucose Media Reflecting Improvements in Mitochondrial Respiration and Cell Growth Rate

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 109-109
Author(s):  
Matthew S Crouse ◽  
Wellison Jarles Da Silva Diniz ◽  
Joel Caton ◽  
Carl R Dahlen ◽  
Lawrence P Reynolds ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cell Proliferation ◽  
Cell Growth ◽  
Vitamin B12 ◽  
Mitochondrial Respiration ◽  
Cytosine Methylation ◽  
Biological Processes ◽  
Cell Growth Rate ◽  
Metabolic Processes ◽  
Positive Regulation

Abstract We hypothesized that supplementation of one-carbon metabolites (OCM: methionine, folate, choline, and vitamin B12) to bovine embryonic tracheal fibroblasts in divergent glucose media would alter cytosine methylation, and alterations in cytosine methylation will reflect biological processes matching previously improved mitochondrial respiration, cell proliferation, and cell growth rate data. Cells were cultured with 1g/L glucose (Low) or 4.5g/L glucose (High). Control medium (CON) contained basal concentrations of folate (0.001g/L), choline (0.001g/L), vitamin B12 (4µg/L), and methionine (0.015g/L). The OCM were supplemented at 2.5 and 5 times (2.5X and 5X, respectively) the CON media, except methionine was limited to 2X across all supplemented treatments. Cells were passaged three times in their treatment media before DNA extraction. Reduced representation bisulfite sequencing was adopted to analyze and compare the genomic methylation patterns within and across treatments using edgeR. Biological processes (BP) were retrieved based on the nearest genes of differentially methylated cytosines (P < 0.01) for each comparison between treatments. In both Low and High treatments, greater OCM increased the proportion of hypomethylated vs. hypermethylated cytosines. Functional analyses pointed out positive regulation of BP related to energy metabolism, except for the contrasts within the High group. Among the BP, we can highlight positive regulation of: GTPase activity, catalytic activity, molecular function, protein modification processes, phosphorylation, protein phosphorylation, cellular protein metabolic processes, MAPK cascade, and metabolic processes. These data support previously reported results from this experiment that showed increased mitochondrial respiration, cell proliferation, and growth rates with increasing OCM levels. We interpret these data to imply that when energy and OCM requirements are met for growth and basal methylation levels, DNA methylation levels decrease which may allow for greater transcription. Thus, OCM can be utilized for other functions such as polyamine synthesis, nucleotide synthesis, energetic metabolites, and phosphatidylcholine synthesis. USDA is an equal opportunity provider and employer.

PGE2 inhibition & interferon-gamma restoration of type 1 T cell growth rate in atopic dermatitis

1993 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Sai C. Chan ◽  
Shi-Hua Li ◽  
William R. Henderson ◽  
Jon M. Hanifin
Keyword(s):  
Growth Rate ◽  
Atopic Dermatitis ◽  
T Cell ◽  
Cell Growth ◽  
Interferon Gamma ◽  
Cell Growth Rate ◽  
T Cell Growth

The uptake of amino acids by mouse cells (strain LS) during growth in batch culture and chemostat culture: the influence of cell growth rate

1967 ◽  
Vol 168 (1013) ◽  
pp. 421-438 ◽  
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Amino Acid ◽  
Cell Growth ◽  
Glutamic Acid ◽  
Batch Culture ◽  
Amino Acid Uptake ◽  
Essential Amino Acids ◽  
Growth Yields ◽  
Acid Uptake

The uptake of thirteen essential amino acids by mouse LS cells in suspension culture was determined by bacteriological assay methods. Chemostat continuous-flow cultures were used to determine the effect of different cell growth rates on the quantitative amino acid requirements for growth. The growth yields of the cells ( Y = g cell dry weight produced/g amino acid utilized) were calculated for each of the essential amino acids. A mixture of the non-essential amino acids, serine, alanine and glycine increased the cell yield from the essential amino acids. The growth yields from nearly all the essential amino acids in batch culture were increased when glutamic acid was substituted for the glutamine in the medium. The growth yields from the amino acids in batch culture were much less at the beginning than at the end of the culture. The highest efficiencies of conversion of amino acids to cell material were obtained by chemostat culture. When glutamic acid largely replaced the glutamine in the medium the conversion of amino acid nitrogen to cell nitrogen was 100 % efficient (that is, the theoretical yield was obtained) at the optimum growth rate (cell doubling time, 43 h). The maximum population density a given amino acid mixture will support can be calculated from the data. It is concluded that in several routinely used tissue culture media the cell growth is limited by the amino acid supply. In batch culture glutamine was wasted by (1) its spontaneous decomposition to pyrrolidone carboxylic acid and ammonia, and (2) its enzymic breakdown to glutamic acid and ammonia, but also glutamine was used less efficiently than glutamic acid. Study of the influence of cell growth rate on amino acid uptake rates per unit mass of cells indicated that a marked change in amino acid metabolism occurred at a specific growth rate of 0.4 day -1 (cell doubling time, 43 h). With decrease in specific growth rate below 0.4 day -1 there was a marked stimulation of amino acid uptake rate per cell and essential amino acids were consumed increasingly for functions other than synthesis of cell material.

Temperature-sensitive mutants of MscL mechanosensitive channel

2019 ◽  
Vol 166 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Naoto Owada ◽  
Megumi Yoshida ◽  
Kohei Morita ◽  
Kenjiro Yoshimura
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Structural Change ◽  
Cell Growth ◽  
Thermodynamic Stability ◽  
Transmembrane Helix ◽  
Mechanosensitive Channel ◽  
Temperature Sensitive ◽  
Temperature Sensitive Mutants ◽  
Membrane Stretching

Abstract MscL is a mechanosensitive channel that undergoes a global conformational change upon application of membrane stretching. To elucidate how the structural stability and flexibility occur, we isolated temperature-sensitive (Ts) mutants of Escherichia coli MscL that allowed cell growth at 32°C but not at 42°C. Two Ts mutants, L86P and D127V, were identified. The L86P mutation occurred in the second transmembrane helix, TM2. Substitution of residues neighbouring L86 with proline also led to a Ts mutation, but the substitution of L86 with other amino acids did not result in a Ts phenotype, indicating that the Ts phenotype was due to a structural change of TM2 helix by the introduction of a proline residue. The D127V mutation was localized in the electrostatic belt of the bundle of cytoplasmic helices, indicating that stability of the pentameric bundle of the cytoplasmic helix affects MscL structure. Together, this study described a novel class of MscL mutations that were correlated with the thermodynamic stability of the MscL structure.

scholarly journals ANTAGONISM BY DIBUTYRYL ADENOSINE CYCLIC 3',5'-MONOPHOSPHATE AND TESTOSTERONE OF CELL ROUNDING REACTIONS

1973 ◽  
Vol 59 (2) ◽  
pp. 471-479 ◽  
Author(s):  
Brian Storrie
Keyword(s):  
Growth Rate ◽  
Protein Synthesis ◽  
Cell Growth ◽  
Concanavalin A ◽  
Divalent Cations ◽  
Cell Growth Rate ◽  
Dibutyryl Camp ◽  
Cell Rounding ◽  
Drug Removal ◽  
Kinetics Of

In an attempt to understand further the mechanism of the morphological and functional "reverse transformation" of CHO-K1 cells induced by dibutyryl adenosine cyclic 3',5'-monophosphate (cAMP) and testosterone, the kinetics of variation in the susceptibility of cells to rounding after the addition or deletion of dibutyryl cAMP and testosterone have been investigated. Changes in susceptibility to cell rounding upon removal of divalent cations or pulse exposure to concanavalin A were complete within 0.5–1 h after addition or deletion of drug. In comparison, the gross conversion of CHO-K1 cells from epithelial- to fibroblast-like morphology after drug treatment or the converse change after drug removal required 8 or 4 h, respectively. The effects on cell rounding are not caused by an effect of dibutyryl cAMP upon cell growth rate. Inhibitor experiments indicate that the changes investigated do not require continued RNA or protein synthesis and are not prevented by agents which depolymerize microtubules.

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