scholarly journals Using immunohistochemistry to study plant metabolism: the examples of its use in the localization of amino acids in plant tissues, and of phosphoenolpyruvate carboxykinase and its possible role in pH regulation

2001 ◽  
Vol 52 (356) ◽  
pp. 565-576 ◽  
Author(s):  
Robert P. Walker ◽  
Zhu‐Hui Chen ◽  
Karen E. Johnson ◽  
Franco Famiani ◽  
Laszlo Tecsi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Ph Regulation ◽  
Plant Tissues ◽  
Plant Metabolism

scholarly journals Phenylalanine and Tyrosine as Exogenous Precursors of Wheat (Triticum aestivum L.) Secondary Metabolism through PAL-Associated Pathways

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 476 ◽  
Author(s):  
Pavel Feduraev ◽  
Liubov Skrypnik ◽  
Anastasiia Riabova ◽  
Artem Pungin ◽  
Elina Tokupova ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Metabolic Pathways ◽  
Phenylalanine Ammonia Lyase ◽  
Higher Plants ◽  
Aromatic Amino Acids ◽  
Triticum Aestivum L ◽  
Plant Tissues ◽  
Plant Metabolism ◽  
Wide Range ◽  
Number Of Genes

Reacting to environmental exposure, most higher plants activate secondary metabolic pathways, such as the metabolism of phenylpropanoids. This pathway results in the formation of lignin, one of the most important polymers of the plant cell, as well as a wide range of phenolic secondary metabolites. Aromatic amino acids, such as phenylalanine and tyrosine, largely stimulate this process, determining two ways of lignification in plant tissues, varying in their efficiency. The current study analyzed the effect of phenylalanine and tyrosine, involved in plant metabolism through the phenylalanine ammonia-lyase (PAL) pathway, on the synthesis and accumulation of phenolic compounds, as well as lignin by means of the expression of a number of genes responsible for its biosynthesis, based on the example of common wheat (Triticum aestivum L.).

Structure and function of the NHE1 isoform of the Na+/H+ exchanger

2002 ◽  
Vol 80 (5) ◽  
pp. 499-508 ◽  
Author(s):  
Emily Slepkov ◽  
Larry Fliegel
Keyword(s):  
Amino Acids ◽  
Intracellular Ph ◽  
Ph Regulation ◽  
Integral Membrane Protein ◽  
Amino Acid Residues ◽  
Transmembrane Helices ◽  
Cytoskeletal Organization ◽  
Transmembrane Segments ◽  
And Function ◽  
Extracellular Sodium

The Na+/H+ exchanger is a ubiquitous, integral membrane protein involved in pH regulation. It removes intracellular acid, exchanging a proton for an extracellular sodium ion. There are seven known isoforms of this protein that are the products of distinct genes. The first isoform discovered (NHE1) is ubiquitously distributed throughout the plasma membrane of virtually all tissues. It plays many different physiological roles in mammals, including important functions in regulation of intracellular pH, in heart disease, and in cytoskeletal organization. The first 500 amino acids of the protein are believed to consist of 12 transmembrane helices, a membrane-associated segment, and two reentrant loops. A C-terminal regulatory domain of approximately 315 amino acids regulates the protein and mediates cyto skel etal interactions. Studies are underway to determine the amino acid residues important in NHE1 function. At present, it is clear that transmembrane segment IV is important in NHE1 function and that transmembrane segments VII and IX are also involved in transport. Further experiments are required to elucidate the mechanism of transport and regulation of this multifunctional protein.Key words: cation transport, intracellular pH, membrane proteins, Na+/H+ exchanger.

γ-Amino-Butyric Acid and β-Alanine in Plant Tissues: Amino-Acids of the Apple Fruit

Nature ◽  
1950 ◽  
Vol 165 (4201) ◽  
pp. 716-717 ◽  
Author(s):  
A. C. HULME ◽  
W. ARTHINGTON
Keyword(s):  
Amino Acids ◽  
Butyric Acid ◽  
Apple Fruit ◽  
Plant Tissues ◽  
Amino Butyric Acid

scholarly journals Effect of renal tubule-specific knockdown of the Na+/H+exchanger NHE3 in Akita diabetic mice

2019 ◽  
Vol 317 (2) ◽  
pp. F419-F434 ◽  
Author(s):  
Akira Onishi ◽  
Yiling Fu ◽  
Manjula Darshi ◽  
Maria Crespo-Masip ◽  
Winnie Huang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Tricarboxylic Acid Cycle ◽  
Branched Chain Amino Acids ◽  
Tricarboxylic Acid ◽  
Proximal Tubules ◽  
Wild Type ◽  
Kidney Weight ◽  
Acid Cycle ◽  
Branched Chain

Na+/H+exchanger isoform 3 (NHE3) contributes to Na+/bicarbonate reabsorption and ammonium secretion in early proximal tubules. To determine its role in the diabetic kidney, type 1 diabetic Akita mice with tubular NHE3 knockdown [Pax8-Cre; NHE3-knockout (KO) mice] were generated. NHE3-KO mice had higher urine pH, more bicarbonaturia, and compensating increases in renal mRNA expression for genes associated with generation of ammonium, bicarbonate, and glucose (phosphoenolpyruvate carboxykinase) in proximal tubules and H+and ammonia secretion and glycolysis in distal tubules. This left blood pH and bicarbonate unaffected in nondiabetic and diabetic NHE3-KO versus wild-type mice but was associated with renal upregulation of proinflammatory markers. Higher renal phosphoenolpyruvate carboxykinase expression in NHE3-KO mice was associated with lower Na+-glucose cotransporter (SGLT)2 and higher SGLT1 expression, indicating a downward tubular shift in Na+and glucose reabsorption. NHE3-KO was associated with lesser kidney weight and glomerular filtration rate (GFR) independent of diabetes and prevented diabetes-associated albuminuria. NHE3-KO, however, did not attenuate hyperglycemia or prevent diabetes from increasing kidney weight and GFR. Higher renal gluconeogenesis may explain similar hyperglycemia despite lower SGLT2 expression and higher glucosuria in diabetic NHE3-KO versus wild-type mice; stronger SGLT1 engagement could have affected kidney weight and GFR responses. Chronic kidney disease in humans is associated with reduced urinary excretion of metabolites of branched-chain amino acids and the tricarboxylic acid cycle, a pattern mimicked in diabetic wild-type mice. This pattern was reversed in nondiabetic NHE3-KO mice, possibly reflecting branched-chain amino acids use for ammoniagenesis and tricarboxylic acid cycle upregulation to support formation of ammonia, bicarbonate, and glucose in proximal tubule. NHE3-KO, however, did not prevent the diabetes-induced urinary downregulation in these metabolites.

Fatty acid recycling in adipocytes: a role for glyceroneogenesis and phosphoenolpyruvate carboxykinase

2003 ◽  
Vol 31 (6) ◽  
pp. 1125-1129 ◽  
Author(s):  
C. Forest ◽  
J. Tordjman ◽  
M. Glorian ◽  
E. Duplus ◽  
G. Chauvet ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Amino Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
White Adipose Tissue ◽  
Metabolic Pathway ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Important Pathway ◽  
Low Activity

FA (fatty acid) recycling in adipose tissue appears to be an important pathway for regulating FA release into the blood during fasting. Re-esterification requires G3P (glycerol 3-phosphate), which cannot be synthesized from glucose because glycolysis is much reduced under such circumstances. In addition, G3P can scarcely originate from glycerol since glycerol kinase has a very low activity in white adipose tissue. It was shown about 35 years ago that a metabolic pathway named glyceroneogenesis, which allows G3P synthesis from non-carbohydrate precursors like pyruvate, lactate or amino acids, is activated during fasting. The major enzyme in this pathway was shown to be PEPCK-C [cytosolic phosphoenolpyruvate carboxykinase (GTP); EC 4.1.1.32]. The present review analyses the mechanisms by which a series of hormones and nutrients affect PEPCK-C gene transcription and glyceroneogenesis and describes evidence for dysregulation of this pathway in type 2 diabetes.

scholarly journals HISTOCHEMICAL DIFFERENTIATION BETWEEN TYROSINE AND CHLOROGENIC ACID IN PLANT TISSUES I. NITROUS ACID REACTIONS AND METAL CHELATION OF NITROSOTYROSINE

1968 ◽  
Vol 16 (3) ◽  
pp. 191-198 ◽  
Author(s):  
R. M. REEVE
Keyword(s):  
Amino Acids ◽  
Chlorogenic Acid ◽  
Nitrous Acid ◽  
Metal Chelate ◽  
Ultrastructural Localization ◽  
Plant Tissues ◽  
Metal Chelation ◽  
Copper Chelation ◽  
Acid Reaction ◽  
Color Reactions

Copper chelation of nitrosotyrosine has been found useful for histochemical localization for tyrosine in thick, fresh sections of large celled plant tissues. The nitrous acid reaction for ortho-dihydroxyphenolics also has been found useful for localization of chlorogenic acid, caffeic acid and dihydroxyphenylalanine in plant tissues. Application of these tests separately to serially adjacent sections demonstrated the distribution of tyrosine and chlorogenic acid in different plant tissues. Tests tube reactions on known substances verified specificity and also demonstrated that the presence of other amino acids and phenolics did not interfere with the positive test for tyrosine. The color reactions are sufficiently intense for stereoscopic microscopy and tested sections may be measured photometrically. Further adaptability of the nitrosotyrosine-metal chelate reaction to procedures for ultrastructural localization is suggested.

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