The effect of cycloheximide on amide formation in maize roots

1973 ◽  
Vol 51 (1) ◽  
pp. 91-95 ◽  
Author(s):  
Ann Oaks ◽  
F. J. Johnson
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Root Tip ◽  
Minor Effect ◽  
Root Tips ◽  
Corn Root ◽  
Basic Amino Acids ◽  
Maize Roots ◽  
A Minor ◽  
Mature Root

Cycloheximide inhibits the incorporation of acetate-2-14C into protein and into asparagine in corn root tips. It also causes an accumulation of glutamine and, over a concentration range of 0.4 to 5.0 μg/ml, a transient accumulation of the neutral and basic amino acids. In mature sections, cycloheximide inhibits protein synthesis but causes an increase in the incorporation of radioactivity into both glutamine and asparagine. Azaserine, a glutamine analogue, also inhibits the formation of asparagine in root-tip sections but has only a minor effect on protein synthesis. In mature root sections, there is an accumulation of glutamine but no effect on asparagine formation when azaserine is used. Glutamine additions to root tips or mature root sections affect neither asparagine formation nor protein synthesis. We conclude that cycloheximide is behaving as a glutamine analogue in its effect on asparagine biosynthesis, and that its effect as a glutamine analogue is lost as cells mature.

scholarly journals Distinct changes in mature root and growing root tip proteomes underlie physiological responses of bread wheat to salinity stress

2021 ◽  
Author(s):  
Bhagya M Dissanayake ◽  
Christiana Staudinger ◽  
Rana Munns ◽  
Nicolas L Taylor ◽  
A. Harvey Millar
Keyword(s):  
Protein Synthesis ◽  
Tca Cycle ◽  
Wheat Root ◽  
Root Tip ◽  
Root Tips ◽  
Wheat Roots ◽  
Root Tissues ◽  
Related Proteins ◽  
The Impact ◽  
Mature Root

The impact of salinity on wheat plants is often studied by analysis of shoot responses, even though the main mechanism of tolerance is shoot Na+ exclusion. There is a need to understand the molecular responses of root tissues that directly experience rising NaCl concentrations. We have combined analysis of root growth, ion content and respiration with proteome responses in wheat root tip and mature root tissues under saline conditions. We find significant changes in translation and protein synthesis, energy metabolism and amino acid metabolism in a root tissue specific manner. Translation and protein synthesis related proteins showed significant decreases in abundance only in root tips, as did most of the glycolytic enzymes and selected TCA cycle enzymes and ATP synthase subunits. This selective root tip proteome response indicates protein synthesis capacity and energy production were impaired under salt stress, correlating with the anatomical response of roots and reduced root tip respiration rate. Wheat roots respond directly to soil salinity, therefore shoot responses such as reduction in shoot growth and photosynthetic capacity need to be considered in light of these effects.

Proteomic Analyses of Soybean Root Tips During Germination

2014 ◽  
Vol 21 (12) ◽  
pp. 1308-1319
Author(s):  
Setsuko Komatsu ◽  
Myeong W. Oh ◽  
Hee Y. Jang ◽  
Soo J. Kwon ◽  
Hye R. Kim ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Proteomic Analysis ◽  
Plant Root ◽  
Root Tip ◽  
Root Tips ◽  
Form Complex ◽  
Molecular Weights ◽  
Soybean Seedlings ◽  
2D Gel ◽  
Proteomic Techniques

Plant root systems form complex networks with the surrounding soil environment and are controlled by both internal and external factors. To better understand the function of root tips of soybean during germination, three proteomic techniques were used to analyze the protein profiles of root tip cells. Proteins were extracted from the root tips of 4-dayold soybean seedlings and analyzed using two-dimensional (2D) gel electrophoresis-based proteomics, SDS-gel based proteomics, and gel-free proteomics techniques. A total of 121, 862, and 341 proteins were identified in root tips using the 2D gel-based, SDS gel-based, and gel-free proteomic techniques, respectively. The proteins identified by 2D gel-based proteomic analysis were predominantly localized in the cytoplasm, whereas nuclear-localized proteins were most commonly identified by the SDS gel-based and gel-free proteomics techniques. Of the 862 proteins identified in the SDS gelbased proteomic analysis, 190 were protein synthesis-related proteins. Furthermore, 24 proteins identified using the 2Dgel based proteomic technique shifted between acidic and basic isoelectric points, and 2 proteins, heat shock protein 70.2 and AAA-type ATPase, displayed two different molecular weights at the same isoelectric point. Taken together, these results suggest that a number of proteins related to protein synthesis and modification are activated in the root tips of soybean seedlings during germination.

The influence of nitrate on the induction of nitrate reductase in maize roots

1973 ◽  
Vol 51 (6) ◽  
pp. 1255-1258 ◽  
Author(s):  
D. L. Stevens ◽  
Ann Oaks
Keyword(s):  
Nitrate Reductase ◽  
Maize Root ◽  
Lag Phase ◽  
Root Tips ◽  
Final Level ◽  
Maize Roots ◽  
Mature Root

A concentration of 10 mM NO3 saturates the induction of nitrate reductase in maize root tips whereas concentrations up to 100 mM do not saturate the induction in mature root sections. Increasing concentrations of nitrate from 1 to 25 mM have no effect on either the lag phase, or the phase of rapid increase of the enzyme. They do influence the final level of enzyme obtained at 8 h.

The effect of cycloheximide and cycloheximide analogues on protein, asparagine, and glutamine synthesis in corn root tips

1978 ◽  
Vol 56 (22) ◽  
pp. 2873-2877 ◽  
Author(s):  
W. George Wheatley ◽  
Ann Oaks
Keyword(s):  
Protein Synthesis ◽  
Basic Amino Acid ◽  
Hydroxyl Group ◽  
Root Tips ◽  
Inhibit Protein Synthesis ◽  
Corn Root ◽  
Structural Analogues ◽  
Ketone Carbonyl ◽  
Glutamine Synthesis ◽  
Organic Acids And Sugars

Cycloheximide treatment (3.6 × 10−6 M) inhibits the incorporation of [2-14C]acetate into protein, asparagine, and the organic acids and sugars fraction. At the same time, it enhances the release of 14CO2 and the incorporation of carbon into glutamine and the neutral and basic amino acid fraction. Eight structural analogues of cycloheximide were tested for their effects on protein, asparagine, and glutamine formation in corn root tips. Two analogues, cycloheximide acetate and streptovitacin A (at a concentration of 1.8 × 10−5 M), acted in a manner similar to cycloheximide. Their effect was to inhibit protein and asparagine synthesis and to enhance glutamine formation. Six other analogues (1.8 × 10−5 M) had no marked effect on these fractions. The results of this investigation indicate that the structural analogues which inhibit asparagine formation in corn root tips also inhibit protein synthesis. The results suggest that the hydroxyl group of the hydroxyethylglutarimide portion of the cycloheximide molecule and the ketone-carbonyl group of the cyclohexanone ring are important for their action on protein synthesis in corn root tips.

scholarly journals Polyprenyl phosphate sugars synthesized during slime-polysaccharide production by membranes of the root-cap cells of maize (Zea mays)

1979 ◽  
Vol 178 (3) ◽  
pp. 661-671 ◽  
Author(s):  
J R Green ◽  
D H Northcote
Keyword(s):  
Endoplasmic Reticulum ◽  
Zea Mays ◽  
Neutral Lipids ◽  
Root Tip ◽  
Synthetase Activity ◽  
Root Tips ◽  
Maize Roots ◽  
Glucose Derivatives

Two types of experiments were carried out; either maize roots were incubated in L-[1-3H]fucose or membranes were prepared from root tips and these were incubated with GDP-L-[U-14C]fucose or UDP-D-[U-4C]glucose. The radioactively labelled lipids that were synthesized in vivo and in vitro were extracted and separated into polar and neutral components. The polar lipids had the characteristics of polyprenyl phosphate and diphosphate fucose or glucose derivatives, and the neutral lipids of sterol glycosides (fucose or glucose). A partial separation of the glycolipid synthetase reactions was achieved. Membranes were fractionated into material that sedimented at 20,000g and 100,000g. Most of the polar glycolipid synthetase activity (for the incorporation of both fucose and glucose) was located in the 100,000 g pellet, and this activity was probably located in the endoplasmic reticulum. The neutral lipid, which contained fucose, was synthesized mainly by membranes of the 20,000g pellet, and the activity was probably associated with the dictyosomes, whereas the neutral glucolipids were synthesized by all the membrane fractions. It is suggested that the polar (polyprenyl) lipids labelled with fucose could act as possible intermediates during the synthesis of the glycoproteins and slime in the root tip.

Protein synthesis in trifluralin-treated corn root tips

1989 ◽  
Vol 8 (3) ◽  
pp. 205-214 ◽  
Author(s):  
N. D. Camper ◽  
K. L. Ellers
Keyword(s):  
Protein Synthesis ◽  
Root Tips ◽  
Corn Root

scholarly journals The relationship of root-cap slimes to proteins

1974 ◽  
Vol 139 (3) ◽  
pp. 525-534 ◽  
Author(s):  
Kenneth Wright ◽  
D. H. Northcote
Keyword(s):  
Chemical Characteristic ◽  
Wheat Root ◽  
Root Cap ◽  
Water Soluble ◽  
Maize Root ◽  
Root Tip ◽  
Root Tips ◽  
Maize Roots ◽  
Neutral Sugars ◽  
Relationship Of

1. The patterns of incorporation of radioactivity from d-[U-14C]glucose into the pectic components of sections of sycamore roots changed so that sections nearer the tip incorporated relatively more label into arabinose and galactose compared with uronic acid. 2. Radioactive maize root-cap slime was prepared and found to contain three water-soluble component polymers which were electrophoretically (i) neutral, (ii) weakly acidic and (iii) strongly acidic at pH6.5. The neutral component was a glucan. The other components, which could be degraded by trans-elimination, consisted of an acidic backbone chain composed of galacturonic acid and glucose, attached to which were different proportions of neutral sugars. Arabinose, galactose and fucose, the main neutral sugars of the weakly and strongly acidic materials, were absent from the neutral fraction. 3. Fucose was a major sugar in maize-root slime and in a slime of similar composition synthesized by a maize callus of shoot origin. Only trace amounts were found in sycamore, pea and wheat root tips, and in pectin prepared from maize roots and coleoptiles. A high proportion of fucose is therefore a chemical characteristic of maize slime, and slime synthesis indicated a state of differentiation of the tissue. 4. The similarity between the slime and pectin is discussed; slime is a form of pectin modified in such a way as to provide a hydrated protective coating around the root tip.

Effects of Anoxia on Uptake and Loss of Solutes in Roots of Wheat

1992 ◽  
Vol 19 (3) ◽  
pp. 233 ◽  
Author(s):  
H Greenway ◽  
I Waters ◽  
J Newsome
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Soluble Sugars ◽  
Membrane Integrity ◽  
Root Tip ◽  
Root Tips ◽  
Wheat Seedlings ◽  
Root Tissues ◽  
Irreversible Injury

This paper reports on leakage of K+, Cl-, free amino acids and soluble sugars from roots of 4-5-day-old intact wheat seedlings, exposed to anoxia. Leakages were slower from hypoxically than from aerobically pretreated roots. For the first 24 h of anoxia, leakage of K+ and free amino acids was similar, while sugar leakage was slow. Subsequently, leakage of all three solutes usually increased with time. Net losses of K+ and Cl-, after 48 or 72 h exposure of intact seedlings to anoxia, were faster, and/or occurred earlier: (i) in expanding than in expanded root tissues; (ii) at 25� than at 15�C. Re-aeration showed that expanded root tissues retained their capacity to take up K+ and accumulate Cl-, for at least 12 h after the root tips had lost their ability to elongate. Roots which had lost their elongation potential after 20 h of anoxia, as diagnosed by microscopic observation, still had high solute concentrations in the 1-5 mm and 10-20 mm segments from the root tip, but the 0-1 mm apices had lost 70-90% of their K+, free amino acids and soluble sugars. In contrast, solute concentrations were still high in 0-1 mm tips which had not yet lost their elongation potential. Thus, either irreversible injury of the apices is caused by sudden loss of membrane integrity, or there is another cause of death leading to rapid leakage.

scholarly journals Effect of food intake on protein and energy metabolism in finishing beef steers

1987 ◽  
Vol 57 (3) ◽  
pp. 457-465 ◽  
Author(s):  
G. E. Lobley ◽  
Alexmary Connell ◽  
Vivien Buchan
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Food Intake ◽  
Protein Oxidation ◽  
Significant Proportion ◽  
Specific Radioactivity ◽  
Whole Body ◽  
Beef Steers ◽  
Body Protein ◽  
A Minor

1. The effects of progressive reduction in food intake from 1.6 x maintenance (1.6 M) to approximately maintenance (M′) and then to zero (fasting) on energy expenditure and leucine kinetics were examined in Hereford x Friesian finishing beef steers.2. Estimates of whole body protein synthesis and protein oxidation were obtained from the specific radioactivity of free leucine in blood and of exhaled carbon dioxide during continuous infusions of [I-14C]leucine. Protein synthesis contributed a minimum of 0.19 to total heat production across all three intakes.3. The apparent efficiencies with which synthesized protein was retained were 0.28 between 1.6 M and M′ and 1.04 between M′ and fasting. The greater efficiency below M′ reflected probable use of amino acids as energy sources during fasting, which would be spared as soon as feed was available.4. Nitrogen derived from protein oxidation made a minor contribution to urine N at both 1.6 M (0.45) and M′ (0.36) but provided a significant proportion to the increment in urine N between intakes (0.68).5. Amino acid absorption, estimated indirectly as the sum of protein oxidation and protein retention, represented only 0.28 of N intake at M′ and 0.38 at 1.6 M but the contribution to the increment in N intake between these two diet levels was greater (0.56).6. The estimated efficiency of utilization of absorbed amino acids between M′ and 1.6 M was 0.45.

scholarly journals Serum d-serine levels are altered in early phases of Alzheimer’s disease: towards a precocious biomarker

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luciano Piubelli ◽  
Loredano Pollegioni ◽  
Valentina Rabattoni ◽  
Marco Mauri ◽  
Lucia Princiotta Cariddi ◽  
...  
Keyword(s):  
Experimental Data ◽  
Amino Acids ◽  
Disease Progression ◽  
Healthy Subjects ◽  
Enzymatic Degradation ◽  
Serum Levels ◽  
Minor Effect ◽  
Positive Correlation ◽  
A Minor ◽  
Early Phases

Abstractd-Serine acts as a co-agonist of N-methyl-d-aspartate receptors (NMDAR) which appear overactivated in AD, while d-aspartate is a modulatory molecule acting on NMDAR as a second agonist. The aim of this work is to clarify whether the levels of these d-amino acids in serum are deregulated in AD, with the final goal to identify novel and precocious biomarkers in AD. Serum levels of l- and d-enantiomers of serine and aspartate were determined by HPLC using a pre-column derivatization procedure and a selective enzymatic degradation. Experimental data obtained from age-matched healthy subjects (HS) and AD patients were statistically evaluated by considering age, gender, and disease progression, and compared. Minor changes were apparent in the serum l- and d-aspartate levels in AD patients compared to HS. A positive correlation for the d-serine level and age was apparent in the AD cohort. Notably, the serum d-serine level and the d-/total serine ratio significantly increased with the progression of the disease. Gender seems to have a minor effect on the levels of all analytes tested. This work proposes that the serum d-serine level and d-/total serine ratio values as novel and valuable biomarkers for the progression of AD: the latter parameter allows to discriminate CDR 2 and CDR 1 patients from healthy (CDR 0) individuals.

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