scholarly journals Dark Protein Synthesis: Physiological Response to Nutrient Limitation of a Natural Phytoplankton Population

2001 ◽  
Vol 55 (1) ◽  
pp. 1-15
Author(s):  
S. (Satoru) Taguchi ◽  
Edward A. Laws
Keyword(s):  
Protein Synthesis ◽  
Nutrient Limitation ◽  
Physiological Response ◽  
Phytoplankton Population ◽  
Natural Phytoplankton

Physiological Response of Common Cocklebur (Xanthium pensylvanicum) to Glyphosate

Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 874-878 ◽  
Author(s):  
Emerson D. Nafziger ◽  
Fred W. Slife
Keyword(s):  
Protein Synthesis ◽  
Physiological Response ◽  
Carbohydrate Content ◽  
Soluble Carbohydrate ◽  
Nonstructural Carbohydrate ◽  
Diffusive Resistance ◽  
Inhibition Of Protein Synthesis ◽  
Carbohydrate Levels ◽  
P Movement

Thirteen-day-old common cocklebur (Xanthium pensylvanicumWallr. # XANPE) plants were treated with 15 μg glyphosate [N-(phosphonomethyl)glycine] applied to the lowermost true leaves. Growth was inhibited rapidly following treatment. About 56% of applied14C-glyphosate was taken up within 8 h. Within 4 days after treatment, diffusive resistance increased in treated leaves but did not change in untreated leaves. Glyphosate had little effect on nonstructural carbohydrate content of leaves, but soluble carbohydrate levels of stems and roots had increased by 130 and 180%, respectively, by 56 h after treatment. The uptake of33P into roots was unaffected by the herbicide, but transport of P to the aerial tissues was severely inhibited. Effects such as inhibition of P movement could result from inhibition of protein synthesis.

Fatty acid composition in photosynthetic products of natural phytoplankton population in Lake Biwa, Japan

1992 ◽  
Vol 14 (8) ◽  
pp. 1055-1065 ◽  
Author(s):  
Takeo Hama ◽  
Katsuji Matsunaga ◽  
Nobuhiko Handa ◽  
Mikio Takahashi
Keyword(s):  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Lake Biwa ◽  
Phytoplankton Population ◽  
Photosynthetic Products ◽  
Natural Phytoplankton

Day-night changes in production of carbohydrate and protein by natural phytoplankton population from Lake Biwa, Japan

1988 ◽  
Vol 10 (5) ◽  
pp. 941-955 ◽  
Author(s):  
Takeo Hama ◽  
Katsuji Matsunaga ◽  
Nobuhiko Handa ◽  
Mikio Takahashi
Keyword(s):  
Lake Biwa ◽  
Phytoplankton Population ◽  
Natural Phytoplankton

scholarly journals Crosstalk between guanosine nucleotides regulates cellular heterogeneity in protein synthesis during nutrient limitation

2021 ◽  
Author(s):  
Simon Diez ◽  
Molly Hydorn ◽  
Abigail Whalen ◽  
Jonathan Dworkin
Keyword(s):  
Protein Synthesis ◽  
Bacillus Subtilis ◽  
Nutrient Limitation ◽  
Dynamic Environments ◽  
Phenotypic Heterogeneity ◽  
Cellular Heterogeneity ◽  
Microbial Populations ◽  
Low Protein ◽  
Synthesis Activity

Phenotypic heterogeneity of microbial populations can facilitate survival in dynamic environments by generating sub-populations of cells that may have differential fitness in a future environment. Bacillus subtilis cultures experiencing nutrient limitation contain distinct sub-populations of cells exhibiting either comparatively high or low protein synthesis activity. This heterogeneity requires the production of phosphorylated guanosine nucleotides (pp)ppGpp by three synthases: SasA, SasB, and RelA. Here we show that these enzymes differentially affect this bimodality: RelA and SasB are necessary to generate the sub-population of cells exhibiting low protein synthesis whereas SasA is necessary to generate cells exhibiting comparatively higher protein synthesis. The RelA product (pppGpp) allosterically activates SasB and we find, in contrast, that the SasA product (pGpp) competitively inhibits this activation. Finally, we provide in vivo evidence that this antagonistic interaction mediates the observed heterogeneity in protein synthesis. This work therefore identifies the mechanism underlying phenotypic heterogeneity in the central physiological process of protein synthesis.

scholarly journals Atg22 Recycles Amino Acids to Link the Degradative and Recycling Functions of Autophagy

2006 ◽  
Vol 17 (12) ◽  
pp. 5094-5104 ◽  
Author(s):  
Zhifen Yang ◽  
Ju Huang ◽  
Jiefei Geng ◽  
Usha Nair ◽  
Daniel J. Klionsky
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Nutrient Limitation ◽  
Molecular Mechanism ◽  
Nitrogen Starvation ◽  
Nutrient Stress ◽  
Eukaryotic Cells ◽  
Nutrient Pool ◽  
Autophagic Degradation ◽  
Response To Stress

In response to stress conditions (such as nutrient limitation or accumulation of damaged organelles) and certain pathological situations, eukaryotic cells use autophagy as a survival mechanism. During nutrient stress the main purpose of autophagy is to degrade cytoplasmic materials within the lysosome/vacuole lumen and generate an internal nutrient pool that is recycled back to the cytosol. This study elucidates a molecular mechanism for linking the degradative and recycling roles of autophagy. We show that in contrast to published studies, Atg22 is not directly required for the breakdown of autophagic bodies within the lysosome/vacuole. Instead, we demonstrate that Atg22, Avt3, and Avt4 are partially redundant vacuolar effluxers, which mediate the efflux of leucine and other amino acids resulting from autophagic degradation. The release of autophagic amino acids allows the maintenance of protein synthesis and viability during nitrogen starvation. We propose a “recycling” model that includes the efflux of macromolecules from the lysosome/vacuole as the final step of autophagy.

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