Influence of oxime ether safeners and metolachlor on acetate incorporation into lipids and on acetyl-CoA carboxylase of grain sorghum

1. Although citrate is known to activate purified preparations of acetyl-CoA carboxylase, it had no stimulatory effect on the incorporation of [14C]acetate into long-chain fatty acids in a whole homogenate of rat liver (S0.7) under conditions in which the activity of acetyl-CoA carboxylase was rate-limiting for fatty acid synthesis. 2. The rate of incorporation of acetyl carbon into fatty acids was estimated in S0.7 preparations incubated with [14C]acetate, by measuring the specific radioactivity of the acetyl carbon of acetyl-CoA and the incorporation of 14C into fatty acids. These estimates were compared with estimates of acetyl-CoA carboxylase activity in the S0.7 preparation obtained by direct assay in conditions in which the enzyme was in the fully activated state. 3. In the absence of citrate, incorporation of acetyl carbon into fatty acids was about 75% of the value expected if the acetyl-CoA carboxylase in the S0.7 preparation were in the fully activated state. 4. Incorporation of acetyl carbon into fatty acids in the S0.7 preparation was stimulated by citrate, but the effect was many times less than the stimulation of [14C]acetate incorporation by citrate in particle-free preparations. 5. When the mitochondria and microsomes were removed from the S0.7 preparation, [14C]acetate incorporation into fatty acids fell to a negligible value and the preparation became highly sensitive to stimulation by citrate. 6. It is suggested that in the presence of mitochondria and microsomes, and in the intact liver cell, the degree of activation of acetyl-CoA carboxylase is such that citrate activation may not be of physiological significance.

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Fatty-acid biosynthesis and acetyl-coa carboxylase as a target of diclofop, fenoxaprop and other aryloxy-phenoxy-propionic acid herbicides

Zeitschrift für Naturforschung C ◽

10.1515/znc-1988-1-212 ◽

1988 ◽

Vol 43 (1-2) ◽

pp. 47-54 ◽

Cited By ~ 53

Author(s):

Klaus Kobek ◽

Manfred Focke ◽

K. Lichtenthaler Botanisches

Keyword(s):

Fatty Acid ◽

Propionic Acid ◽

Fatty Acid Biosynthesis ◽

De Novo ◽

Free Acid ◽

Acetate Incorporation ◽

Acetyl Coa Carboxylase ◽

Acid Biosynthesis ◽

Acetyl Coa ◽

Acid Herbicides

The effect of the herbicides and aryloxy-phenoxy-propionic acid derivatives diclofop, fenoxaprop, fluazifop and haloxyfop and their ethyl, methyl or butyl esters on the de novo fatty-acid biosynthesis of isolated chloroplasts was investigated with intact chloroplasts isolated from sensitive grasses (Poaceae) and tolerant dicotyledonous plants (Pisum, Spinacia). The 4 herbicides (free-acid form) block the de novo fatty-acid biosynthesis ([2-14C]acetate incorporation into the total fatty-acid fraction) of the sensitive Avena chloroplasts in a dose-dependent manner. The I50- values (a 50% inhibition of the [14C]acetate incorporation) lie in the range of 10-7 to 2 x 10-6 ᴍ. The ethyl or methyl esters (diclofop, fenoxaprop, haloxyfop) and butyl ester (fluazifop) do not affect the de novo fatty-acid biosynthesis of isolated chloroplasts or only at a very high concentration of ca. 10-4 ᴍ. In contrast, the de novo fatty-acid biosynthesis of the tolerant dicotyledonous species (pea, spinach) is not affected by the 4 aryloxy-phenoxy-propionic acid herbicides. In an enzyme preparation isolated from chloroplasts of the herbicide-sensitive barley plants the de novo fatty-acid biosynthesis from [14C]acetate and [14C]acetyl-CoA is blocked by all 4 herbicides (free acids), whereas that of [14C]malonate and [14C]malonyl-CoA is not affected. This strongly suggests that the target of all 4 herbicides (free-acid form) is the acetyl-CoA carboxylase within the chloroplasts. The applied ester derivatives, in turn, which are ineffective in the isolated chloroplast test system, have equally little or no effect on the activity of the acetyl-CoA carboxylase. It is assumed that the acetyl-CoA carboxylase of the tolerant dicot plants investigated is modified in such a way that the 4 herbicides cannot bind to and affect the target

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Metabolic adaptations during lactogenesis. Fatty acid and lactose synthesis in cow mammary tissue

Biochemical Journal ◽

10.1042/bj1360741 ◽

1973 ◽

Vol 136 (3) ◽

pp. 741-748 ◽

Cited By ~ 76

Author(s):

R. W. Mellenberger ◽

D. E. Bauman ◽

D. R. Nelson

Keyword(s):

Fatty Acid ◽

Fatty Acid Synthesis ◽

Post Partum ◽

Acid Synthesis ◽

Mammary Tissue ◽

Acetate Incorporation ◽

Acetyl Coa Carboxylase ◽

Tissue Slices ◽

Acetyl Coa ◽

Lactose Synthesis

1. Mammary-tissue biopsies were obtained from multiparous cows at 30 and 7 days pre partum and 7 and 40 days post partum. Investigations of the effect of lactogenesis on fatty acid and lactose synthesis involved measurements of biosynthetic capacity (tissue-slice incubations in vitro) and activities of relevant enzymes. 2. Fatty acid synthesis from acetate increased over 20-fold from 30 days pre partum to 40 days post partum. Changes in the lipogenic capacity of mammary-tissue slices more closely paralleled increases in the activities of acetyl-CoA carboxylase (EC 6.4.1.2) and acetyl-CoA synthetase (EC 6.2.1.1) than of other enzymes involved in acetate incorporation into fatty acids or in NADPH generation. 3. Lactose biosynthesis by mammary-tissue slices, lactose synthetase activity (EC 2.4.1.22) and α-lactalbumin concentration were all negligible at 30 days pre partum but increased 2.5–4-fold between 7 days pre partum and 40 days post partum. Phosphoglucomutase (EC 2.7.5.1), UDP-glucose pyrophosphorylase (EC 2.7.7.9) and UDP-glucose 4-epimerase (EC 5.1.3.2) had substantial activities at 30 days pre partum and increased less dramatically during lactogenesis. 4. Results are consistent with acetyl-CoA carboxylase and perhaps acetyl-CoA synthetase representing the regulatory enzyme(s) in fatty acid synthesis, with lactose synthetase (α-lactalbumin) serving a similar function in lactose biosynthesis.

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Acetyl-CoA carboxylase inhibition alters tubulin acetylation and aggregation in thrombin-stimulated platelets

European Heart Journal ◽

10.1093/eurheartj/ehab724.3372 ◽

2021 ◽

Vol 42 (Supplement_1) ◽

Author(s):

M Octave ◽

L Pirotton ◽

A Ginion ◽

V Robaux ◽

S Lepropre ◽

...

Keyword(s):

Platelet Aggregation ◽

Lipid Content ◽

Thrombus Formation ◽

Lipid Synthesis ◽

Phospholipid Content ◽

Acetate Incorporation ◽

Acetyl Coa Carboxylase ◽

Acetyl Coa ◽

Tubulin Acetylation ◽

Platelet Functions

Abstract Introduction Acetyl-CoA carboxylase (ACC), the first enzyme regulating lipid synthesis, promotes thrombus formation by increasing platelet phospholipid content. Inhibition of its activity decreases lipogenesis and increases the content in acetyl-CoA which can serve as a substrate for protein acetylation. This posttranslational modification plays a key role in the regulation of platelet aggregation, via tubulin acetylation. Purpose To demonstrate that ACC inhibition may affect platelet functions via an alteration of lipid content and/or tubulin acetylation. Methods Platelets were treated 2 hours with CP640.186, a pharmacological ACC inhibitor, prior to thrombin stimulation. Platelet functions were assessed by aggregometry and flow cytometry. Lipogenesis was measured via 14C-acetate incorporation into lipids. Lipidomics analysis was carried out on the commercial Lipidyzer platform. Protein phosphorylation and acetylation were evaluated by western blot. Results Treatment with CP640.186 drastically decreased platelet lipogenesis. However, the quantitative lipidomics analyses showed that preincubation with the compound did not affect global platelet lipid content. Interestingly, this short-term ACC inhibition was sufficient to increase tubulin acetylation level, at basal state and after thrombin stimulation. It was associated with an impaired platelet aggregation, in response to low thrombin concentration, while granules secretion was not affected. Mechanistically, we highlighted a decrease in Rac1 activity, associated with a reduced phosphorylation of its downstream effector PAK2. Surprisingly, actin cytoskeleton was not impacted but we evidenced a significant decrease in ROS production which could result from a decreased NOX2 activity. Conclusion Pharmacological ACC inhibition decreases platelet aggregation upon thrombin stimulation. The mechanism depends on increased tubulin acetylation, with subsequent alteration of the Rac1/PAK2/NOX2 signaling pathway FUNDunding Acknowledgement Type of funding sources: Other. Main funding source(s): Fonds pour la formation à la Recherche dans l'Industrie et l'Agriculture (FRIA)

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Effect of prolactin on enzymes of lipid biosynthesis in mammary gland explants

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1988.255.4.e567 ◽

1988 ◽

Vol 255 (4) ◽

pp. E567-E571 ◽

Cited By ~ 3

Author(s):

S. B. Waters ◽

J. A. Rillema

Keyword(s):

Mammary Gland ◽

Pyruvate Dehydrogenase ◽

Fatty Acid Synthetase ◽

Second Phase ◽

Acetate Incorporation ◽

Acetyl Coa Carboxylase ◽

Lipogenic Enzymes ◽

Acetyl Coa ◽

Additional Increase ◽

Stimulation Of

Prolactin (PRL) stimulates an increased rate of incorporation of [14C]acetate and [3H]glucose into lipids in cultured mammary gland explants from 10- to 14-day-pregnant mice. This response is biphasic with an early increase occurring from 6 through 12 h, and an additional increase from 16 through 24 h. Enzymes likely to be rate limiting to this process include acetyl CoA carboxylase, fatty acid synthetase, acetyl CoA synthetase, and/or pyruvate dehydrogenase. Of these enzymes only pyruvate dehydrogenase activity was elevated at 6 h, suggesting that this enzymatic activity is important in stimulating early increases in lipogenesis after PRL treatment. In addition, the PRL stimulation of pyruvate dehydrogenase may also indirectly stimulate acetyl CoA carboxylase through the generation of citrate; this may explain the early (6-12 h) effect of PRL on [14C]acetate incorporation. After 16 h of PRL treatment, the activities of all the lipogenic enzymes were enhanced. The second phase of PRLs stimulation of lipogenesis thus likely involves the enhanced activities of more than one of the lipogenic enzymes.

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Effects of the Herbicide Sethoxydim and the Safener Dichlormid on Lipid Synthesis and Acetyl-CoA Carboxylase Activity of Grain Sorghum

Zeitschrift für Naturforschung C ◽

10.1515/znc-1991-11-1201 ◽

1991 ◽

Vol 46 (11-12) ◽

pp. 934-938

Author(s):

Kriton K. Hatzios

Keyword(s):

Combined Treatment ◽

Lipid Synthesis ◽

Grain Sorghum ◽

Combined Effects ◽

Acetyl Coa Carboxylase ◽

Total Lipids ◽

High Concentration ◽

Acetyl Coa ◽

Carboxylase Activity ◽

Leaf Protoplasts

The effects of individual or combined treatment of the cyclohexanedione herbicide sethoxydim and the safener dichlormid on total lipid synthesis, protein synthesis and acetyl-CoA carboxylase (ACCase, EC 6.4.1.12) activity of grain sorghum [Sorghum bicolor (L.) M oench, var. G623] were investigated. Sethoxydim and dichlormid were tested at concentrations of 0, 5, 50, and 100 μM each. Sethoxydim applied alone at 50 and 100 μm , inhibited the incorporation of [14C]acetate into total lipids of sorghum leaf protoplasts by more than 50%, following a 4 h incubation. Dichlormid antagonized partially the inhibitory effects of sethoxydim on the incorporation of acetate into total lipids of sorghum protoplasts only when it was used at 100 μM . Sethoxydim applied alone inhibited the incorporation of [14C]leucine into sorghum leaf protoplasts only at 100 μm. Dichlormid was not inhibitory of this process at any concentration. The combined effects of sethoxydim and dichlormid on this process were mainly additive indicating no interactions of the two chemicals. Sethoxydim applied alone at 5 and 50 μM inhibited the activity of ACCase extracted from leaf tissues of grain sorghum seedlings by 58 and 90%, respectively. Addition of the safener dichlormid to the assay medium did not inhibit ACCase activity of sorghum leaves even at the high concentration of 50 μM . The combined effects of sethoxydim and dichlormid on the activity of sorghum ACCase were similar to those observed when sethoxydim was used alone. These results indicate that the protection conferred by dichlormid on grain sorghum against sethoxydim injury can not be explained on the basis of an antagonistic interaction of the two chemicals on target metabolic processes (lipid synthesis) or target enzymes (ACCase).

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Studies on the Inhibition of Biotin-Containing Carboxylases by Acetyl-CoA Carboxylase Inhibitors

Zeitschrift für Naturforschung C ◽

10.1515/znc-1993-3-429 ◽

1993 ◽

Vol 48 (3-4) ◽

pp. 294-300 ◽

Cited By ~ 3

Author(s):

Anja Motel ◽

Simone Günther ◽

Martin Clauss ◽

Klaus Kobek ◽

Manfred Focke ◽

...

Keyword(s):

Fatty Acid ◽

Fatty Acid Biosynthesis ◽

De Novo ◽

Higher Plants ◽

Acetate Incorporation ◽

Acetyl Coa Carboxylase ◽

Acid Biosynthesis ◽

Acetyl Coa ◽

Malonyl Coa ◽

Key Enzyme

In higher plants the biosynthetic machinery of de novo fatty acid biosynthesis, measured as [14C]acetate incorporation into fatty acids, is predominantly located in plastids. A key enzyme in this pathway is the biotin-containing acetyl-CoA carboxylase (ACC , EC 6.4.1.2) which catalyzes the ATP-dependent carboxylation of acetyl-CoA to malonyl-CoA. The ACC from Poaceae is very efficiently blocked by two herbicide classes, the cyclohexane-1,3-diones (e.g. sethoxydim, cycloxydim) and the aryloxyphenoxy-propionic acids (e.g. diclofop, fluazifop). It is shown that within the Poaceae not only different species but also different varieties exist which exhibit an altered sensitivity and tolerance towards both herbicide classes, which points to a mutation of the target enzyme ACC. In purifying the ACC we extended our research to the possible presence of other biotin-containing plant enzymes. In protein preparations from maize, oat, barley, pea and lentil we were able to demonstrate the carboxylation of acetyl-CoA, propionyl-CoA and methylcrotonyl-CoA. The two herbicide classes not only block the ACC, but also the activity of the propionyl-CoA carboxylase (PCC ), whereas the methylcrotonyl- CoA carboxylase (MCC ), a distinct biotin-containing enzyme from mitochondria, is not affected. MCC may play a role in isoprenoid catabolism. Whether PCC is a separate plastid enzyme or only a side activity of ACC is under current investigation. The efficiency of the graminicides in sensitive Poaceae is then not only determined by the inhibition of ACC, malonyl-CoA and fatty acid biosynthesis, but also by the exclusion of the PCC-catalyzed metabolic pathways of the plant cell.

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