scholarly journals Cytotoxic Mechanism of Excess Polyamines Functions through Translational Repression of Specific Proteins Encoded by Polyamine Modulon

2020 ◽  
Vol 21 (7) ◽  
pp. 2406
Author(s):  
Akihiko Sakamoto ◽  
Junpei Sahara ◽  
Gota Kawai ◽  
Kaneyoshi Yamamoto ◽  
Akira Ishihama ◽  
...  
Keyword(s):  
Cell Growth ◽  
Initiation Site ◽  
Coli Strain ◽  
Translational Repression ◽  
Rrna Transcription ◽  
Specific Proteins ◽  
Cell Growth And Viability ◽  
Cytotoxic Mechanism ◽  
Exogenous Spermidine ◽  
Excessive Accumulation

Excessive accumulation of polyamines causes cytotoxicity, including inhibition of cell growth and a decrease in viability. We investigated the mechanism of cytotoxicity caused by spermidine accumulation under various conditions using an Escherichia coli strain deficient in spermidine acetyltransferase (SAT), a key catabolic enzyme in controlling polyamine levels. Due to the excessive accumulation of polyamines by the addition of exogenous spermidine to the growth medium, cell growth and viability were markedly decreased through translational repression of specific proteins [RMF (ribosome modulation factor) and Fis (rRNA transcription factor) etc.] encoded by members of polyamine modulon, which are essential for cell growth and viability. In particular, synthesis of proteins that have unusual locations of the Shine–Dalgarno (SD) sequence in their mRNAs was inhibited. In order to elucidate the molecular mechanism of cytotoxicity by the excessive accumulation of spermidine, the spermidine-dependent structural change of the bulged-out region in the mRNA at the initiation site of the rmf mRNA was examined using NMR analysis. It was suggested that the structure of the mRNA bulged-out region is affected by excess spermidine, so the SD sequence of the rmf mRNA cannot approach initiation codon AUG.

scholarly journals A Unifying Model for the Role of Polyamines in Bacterial Cell Growth, the Polyamine Modulon

2004 ◽  
Vol 279 (44) ◽  
pp. 46008-46013 ◽  
Author(s):  
Madoka Yoshida ◽  
Keiko Kashiwagi ◽  
Ai Shigemasa ◽  
Shiho Taniguchi ◽  
Kaneyoshi Yamamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Cell Growth ◽  
Iron Uptake ◽  
Physiological Role ◽  
Normal Position ◽  
Specific Proteins ◽  
The Common ◽  
Cell Growth And Viability

We reported previously that the synthesis of specific proteins such as OppA, Cya, and RpoS (σ38), which are important for cell growth and viability, is stimulated by polyamines at the level of translation. In this study we found that the synthesis of FecI and Fis was also stimulated by polyamines at the level of translation. The FecI and Fis proteins enhance the expression of mRNAs that are involved in iron uptake and energy metabolism and the expression of rRNA and some tRNAs. The Shine-Dalgarno (SD) sequence of their mRNAs was not obvious or was not located at the usual position. When the SD sequences were created at the normal position on these mRNAs, protein synthesis was no longer influenced by polyamines. Thus, the common characteristic of these mRNAs was to have a weak or ineffective SD sequence. We propose that a group of genes whose expression is enhanced by polyamines at the level of translation be referred to as a “polyamine modulon.” By DNA microarray, we found that 309 of 2,742 mRNA species were upregulated by polyamines. Among the 309 up-regulated genes, transcriptional enhancement of at least 58 genes might be attributable to increased levels of the transcription factors Cya, RpoS, FecI, and Fis, which are all organized in the polyamine modulon. This unifying molecular mechanism is proposed to underlie the physiological role of polyamines in controlling the growth ofEscherichia coli.

Effect of Different Cell Culture Medium Surfactants on Cell Growth and Viability

2010 ◽  
pp. 819-822 ◽  
Author(s):  
Kristina Martinelle ◽  
Annika Mattsson ◽  
Brita Rippner-Blomqvist ◽  
Elisabeth Lindner
Keyword(s):  
Cell Culture ◽  
Cell Growth ◽  
Culture Medium ◽  
Cell Culture Medium ◽  
Cell Growth And Viability

scholarly journals Fetal Bovine Serum-Derived Extracellular Vesicles Persist within Vesicle-Depleted Culture Media

2018 ◽  
Vol 19 (11) ◽  
pp. 3538 ◽  
Author(s):  
Brandon Lehrich ◽  
Yaxuan Liang ◽  
Pooya Khosravi ◽  
Howard Federoff ◽  
Massimo Fiandaca
Keyword(s):  
Cell Growth ◽  
Extracellular Vesicles ◽  
Bovine Serum ◽  
Culture Media ◽  
Fetal Bovine Serum ◽  
Cellular Growth ◽  
Primary Astrocyte ◽  
Fetal Bovine ◽  
Cell Growth And Viability

It is known that culture media (CM) promotes cellular growth, adhesion, and protects explanted primary brain cells from in vitro stresses. The fetal bovine serum (FBS) supplement used in most CM, however, contains significant quantities of extracellular vesicles (EVs) that confound quantitative and qualitative analyses from the EVs produced by the cultured cells. We quantitatively tested the ability of common FBS EV-depletion protocols to remove exogenous EVs from FBS-supplemented CM and evaluated the influence such methods have on primary astrocyte culture growth and viability. We assessed two methodologies utilized for FBS EV removal prior to adding to CM: (1) an 18-h ultracentrifugation (UC); and (2) a commercial EV-depleted FBS (Exo-FBS™). Our analysis demonstrated that Exo-FBS™ CM provided the largest depletion (75%) of total FBS EVs, while still providing 6.92 × 109 ± 1.39 × 108 EVs/mL. In addition, both UC and Exo-FBS™ CM resulted in poor primary astrocyte cell growth and viability in culture. The two common FBS EV-depletion methods investigated, therefore, not only contaminate in vitro primary cell-derived EV analyses, but also provide a suboptimal environment for primary astrocyte cell growth and viability. It appears likely that future CM optimization, using a serum-free alternative, might be required to advance analyses of cell-specific EVs isolated in vitro.

scholarly journals Effects of chronic 5′-{[(Z)-4-amino-2-butenyl]methylamino)-5′-deoxy- adenosine (AbeAdo) treatment on polyamine and eIF-5A metabolism in AbeAdo-sensitive and -resistant L1210 murine leukaemia cells

1993 ◽  
Vol 290 (1) ◽  
pp. 115-121 ◽  
Author(s):  
T L Byers ◽  
L Wiest ◽  
R S Wechter ◽  
A E Pegg
Keyword(s):  
Cell Growth ◽  
Translation Initiation ◽  
Chronic Exposure ◽  
Limit Of Detection ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Eukaryotic Translation ◽  
L1210 Cells ◽  
Eukaryotic Translation Initiation ◽  
Exogenous Spermidine

We have previously reported that prolonged chronic exposure to the S-adenosyl-L-methionine decarboxylase (AdoMetDC) inhibitor, 5′-([(Z)-4-amino-2-butenyl]methylamino)-5′-deoxy-adenosine (MDL 73811, AbeAdo), leads to cytostasis of L1210 cells [Byers, Ganem and Pegg (1992) Biochem. J. 287, 717-724]. Further studies to investigate the mechanism by which these effects are brought about were carried out by comparing an L1210-derived cell line (R20) that is resistant to AbeAdo with the parent cells. The R20 cells were derived by two rounds of AbeAdo-induced cytostasis followed by rescue with exogenous polyamines. Cytostasis was induced in L1210 cells treated for 12 days with 10 microM AbeAdo; however, exposure to up to 40 microM AbeAdo did not induce cytostasis in R20 cells. Putrescine levels were elevated and spermine levels were depleted in both treated L1210 and treated R20 cells. Spermidine was depleted in treated L1210 cells but was only partly reduced in treated R20 cells. AdoMetDC activity was below the limit of detection in treated L1210 cells but, although greatly reduced, could be measured in the treated R20 cells. The resistance of the R20 cells to the effects of AbeAdo on cell growth and spermidine depletion correlated with reduced AbeAdo accumulation by R20 cells. In the absence of spermidine synthesis, unhypusinated eukaryotic translation initiation factor 5A (eIF-5A) accumulated in AbeAdo-treated L1210 cells. There was no detectable accumulation of unhypusinated eIF-5A in R20 cells. Unhypusinated eIF-5A accumulated during AbeAdo treatment was depleted in L1210 cells rescued by exogenous spermidine. These findings are consistent with the hypothesis that AbeAdo-induced cytostasis is due to the loss of hypusinated eIF-5A. However, spermine was able to rescue AbeAdo-treated L1210 cells without significantly reducing the unhypusinated eIF-5A accumulated during AbeAdo treatment, suggesting that only a small amount of the unmodified protein must be hypusinated to restore cell growth.

scholarly journals Antizyme induction by polyamine analogues as a factor of cell growth inhibition

2002 ◽  
Vol 366 (2) ◽  
pp. 663-671 ◽  
Author(s):  
John L.A. MITCHELL ◽  
Aviva LEYSER ◽  
Michelle S. HOLTORFF ◽  
Jill S. BATES ◽  
Benjamin FRYDMAN ◽  
...  
Keyword(s):  
Cell Growth ◽  
Growth Inhibition ◽  
Feedback Inhibition ◽  
Conformationally Constrained ◽  
Polyamine Analogues ◽  
Polyamine Transport ◽  
Mammalian Cell Growth ◽  
Htc Cells ◽  
Cell Growth And Viability ◽  
Selection Of

The polyamines spermidine and spermine and their diamine precursor putrescine are essential for mammalian cell growth and viability, and strategies are sought for reducing polyamine levels in order to inhibit cancer growth. Several structural analogues of the polyamines have been found to decrease natural polyamine levels and inhibit cell growth, probably by stimulating normal feedback mechanisms. In the present study, a large selection of spermine analogues has been tested for their effectiveness in inducing the production of antizyme, a key protein in feedback inhibition of putrescine synthesis and cellular polyamine uptake. Bisethylnorspermine, bisethylhomospermine, 1,19-bis-(ethylamino)-5,10,15-triazanonadecane, longer oligoamine constructs and many conformationally constrained analogues of these compounds were found to stimulate antizyme synthesis to different levels in rat liver HTC cells, with some producing far more antizyme than the natural polyamine spermine. Uptake of the tested compounds was found to be dependent on, and limited by, the polyamine transport system, for which all these have approximately equal affinity. These analogues differed in their ability to inhibit HTC cell growth during 3days of exposure, and this ability correlated with their antizyme-inducing potential. This is the first direct evidence that antizyme is induced by several polyamine analogues. Selection of analogues with this potential may be an effective strategy for maximizing polyamine deprivation and growth inhibition.

Abstract A20: ARHGEF2 inhibition impairs cell growth and viability in KRAS-dependent cancer cells

2014 ◽  
Author(s):  
Maria Jose Sandi Vargas ◽  
Oliver A. Kent ◽  
Josee Normand ◽  
Robert Rottapel
Keyword(s):  
Cell Growth ◽  
Cancer Cells ◽  
Cell Growth And Viability

Plant Cell Polarity: Creating Diversity from Inside the Box

2019 ◽  
Vol 35 (1) ◽  
pp. 309-336 ◽  
Author(s):  
Andrew Muroyama ◽  
Dominique Bergmann
Keyword(s):  
Cell Wall ◽  
Cell Growth ◽  
Cell Polarity ◽  
Intracellular Trafficking ◽  
Protein Complexes ◽  
Posttranslational Regulation ◽  
Environmental Signals ◽  
Spatial And Temporal Scales ◽  
Specific Proteins ◽  
Made In

Cell polarity in plants operates across a broad range of spatial and temporal scales to control processes from acute cell growth to systemic hormone distribution. Similar to other eukaryotes, plants generate polarity at both the subcellular and tissue levels, often through polarization of membrane-associated protein complexes. However, likely due to the constraints imposed by the cell wall and their extremely plastic development, plants possess novel polarity molecules and mechanisms highly tuned to environmental inputs. Considerable progress has been made in identifying key plant polarity regulators, but detailed molecular understanding of polarity mechanisms remains incomplete in plants. Here, we emphasize the striking similarities in the conceptual frameworks that generate polarity in both animals and plants. To this end, we highlight how novel, plant-specific proteins engage in common themes of positive feedback, dynamic intracellular trafficking, and posttranslational regulation to establish polarity axes in development. We end with a discussion of how environmental signals control intrinsic polarity to impact postembryonic organogenesis and growth.

scholarly journals Enhancement of the Synthesis of RpoE and StpA by Polyamines at the Level of Translation in Escherichia coli under Heat Shock Conditions

2009 ◽  
Vol 191 (17) ◽  
pp. 5348-5357 ◽  
Author(s):  
Yusuke Terui ◽  
Kyohei Higashi ◽  
Yuzuru Tabei ◽  
Hideyuki Tomitori ◽  
Kaneyoshi Yamamoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Structural Change ◽  
Heat Shock ◽  
Cell Growth ◽  
Initiation Site ◽  
Initiation Codon ◽  
Shock Response ◽  
Common Position ◽  
Trna Binding ◽  
Stimulation Of

ABSTRACT Proteins whose synthesis is enhanced by polyamines at the level of translation were identified with a polyamine-requiring mutant cultured in the presence of 0.1% glucose and 0.02% glutamate at 42°C. Polyamines had a greater effect on cell growth at 42°C than at 37°C. At 42°C, the synthesis of RpoE (σ24) and StpA, which are involved in the transcription of a number of heat shock response genes, was stimulated by polyamines at the level of translation. In the rpoE and stpA mRNAs, a Shine-Dalgarno (SD) sequence is located at 13 and 12 nucleotides, respectively, upstream of the initiation codon AUG. When the SD sequences were moved to the more common position 7 nucleotides upstream of the initiation codon AUG, the degree of polyamine stimulation was reduced, although the level of RpoE and StpA synthesis was markedly increased. The mechanism underlying polyamine stimulation of RpoE synthesis was then studied. Polyamine stimulation of RpoE synthesis was reduced by changing the bulged-out structure in the initiation site of rpoE mRNA, although the level of RpoE synthesis increased. A selective structural change of this bulged-out region induced by spermidine at 42°C was observed by circular dichroism. Polyamine stimulation of fMet-tRNA binding to ribosomes at 42°C also disappeared by changing the bulged-out structure in the initiation site of rpoE mRNA. The results suggest that polyamines enhance the synthesis of RpoE by changing the bulged-out structure in the initiation site of rpoE mRNA.

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