scholarly journals Regulation of Rabbit Intestinal Acyl Coenzyme A-Cholesterol Acyltransferase In Vivo and In Vitro

1982 ◽  
Vol 83 (4) ◽  
pp. 873-880 ◽  
Author(s):  
F. Jeffrey Field ◽  
Allen D. Cooper ◽  
Sandra K. Erickson
2007 ◽  
Vol 190 (4) ◽  
pp. 1247-1255 ◽  
Author(s):  
James P. Coleman ◽  
L. Lynn Hudson ◽  
Susan L. McKnight ◽  
John M. Farrow ◽  
M. Worth Calfee ◽  
...  

ABSTRACT Pseudomonas aeruginosa is an opportunistic human pathogen which relies on several intercellular signaling systems for optimum population density-dependent regulation of virulence genes. The Pseudomonas quinolone signal (PQS) is a 3-hydroxy-4-quinolone with a 2-alkyl substitution which is synthesized by the condensation of anthranilic acid with a 3-keto-fatty acid. The pqsABCDE operon has been identified as being necessary for PQS production, and the pqsA gene encodes a predicted protein with homology to acyl coenzyme A (acyl-CoA) ligases. In order to elucidate the first step of the 4-quinolone synthesis pathway in P. aeruginosa, we have characterized the function of the pqsA gene product. Extracts prepared from Escherichia coli expressing PqsA were shown to catalyze the formation of anthraniloyl-CoA from anthranilate, ATP, and CoA. The PqsA protein was purified as a recombinant His-tagged polypeptide, and this protein was shown to have anthranilate-CoA ligase activity. The enzyme was active on a variety of aromatic substrates, including benzoate and chloro and fluoro derivatives of anthranilate. Inhibition of PQS formation in vivo was observed for the chloro- and fluoroanthranilate derivatives, as well as for several analogs which were not PqsA enzymatic substrates. These results indicate that the PqsA protein is responsible for priming anthranilate for entry into the PQS biosynthetic pathway and that this enzyme may serve as a useful in vitro indicator for potential agents to disrupt quinolone signaling in P. aeruginosa.


2013 ◽  
Vol 209 (8) ◽  
pp. 1279-1287 ◽  
Author(s):  
F. Guo ◽  
H. Zhang ◽  
J. M. Fritzler ◽  
S. D. Rider ◽  
L. Xiang ◽  
...  

2005 ◽  
Vol 18 (11) ◽  
pp. 1729-1736 ◽  
Author(s):  
Jørgen Olsen ◽  
Chunze Li ◽  
Inga Bjørnsdottir ◽  
Ulrik Sidenius ◽  
Steen Honoré Hansen ◽  
...  

2017 ◽  
Vol 22 (7) ◽  
pp. 897-905
Author(s):  
Lorenzo Turcano ◽  
Daniela Visaggio ◽  
Emanuela Frangipani ◽  
Antonino Missineo ◽  
Matteo Andreini ◽  
...  

Pseudomonas infections are common among hospitalized, immunocompromised, and chronic lung disease patients. These infections are recalcitrant to common antibacterial therapies due to inherent antibiotic resistance. To meet the need of new anti- Pseudomonas drugs, a sensitive, homogenous, and robust assay was developed with the aim of identifying inhibitors of acyl–coenzyme A synthetases (ACSs) from Pseudomonas. Given the importance of fatty acids for in vivo nutrition of Pseudomonas, such inhibitors might have the potential to reduce the bacterial fitness during infection. The assay, based on a coupled reaction between the Pseudomonas spp. ACS and the firefly luciferase, allowed the identification of three classes of inhibitors by screening of a diverse compound collection. These compounds were confirmed to reversibly bind ACS with potencies in the micromolar range. Two classes were found to compete with acyl–coenzyme A, while the third one was competitive with fatty acid binding. Although these compounds inhibit the bacterial ACS in cell-free assays, they show modest or no effect on Pseudomonas growth in vitro.


2009 ◽  
Vol 191 (6) ◽  
pp. 1749-1755 ◽  
Author(s):  
Jeffrey G. Gardner ◽  
Jorge C. Escalante-Semerena

ABSTRACT This report provides in vivo evidence for the posttranslational control of the acetyl coenzyme A (Ac-CoA) synthetase (AcsA) enzyme of Bacillus subtilis by the acuA and acuC gene products. In addition, both in vivo and in vitro data presented support the conclusion that the yhdZ gene of B. subtilis encodes a NAD+-dependent protein deacetylase homologous to the yeast Sir2 protein (also known as sirtuin). On the basis of this new information, a change in gene nomenclature, from yhdZ to srtN (for sirtuin), is proposed to reflect the activity associated with the YdhZ protein. In vivo control of B. subtilis AcsA function required the combined activities of AcuC and SrtN. Inactivation of acuC or srtN resulted in slower growth and cell yield under low-acetate conditions than those of the wild-type strain, and the acuC srtN strain grew under low-acetate conditions as poorly as the acsA strain. Our interpretation of the latter result was that both deacetylases (AcuC and SrtN) are needed to maintain AcsA as active (i.e., deacetylated) so the cell can grow with low concentrations of acetate. Growth of an acuA acuC srtN strain on acetate was improved over that of the acuA + acuC srtN strain, indicating that the AcuA acetyltransferase enzyme modifies (i.e., inactivates) AcsA in vivo, a result consistent with previously reported in vitro evidence that AcsA is a substrate of AcuA.


1992 ◽  
Vol 262 (4) ◽  
pp. G599-G602
Author(s):  
M. T. Little ◽  
P. Hahn

The development of acyl-coenzyme A: cholesterol acyltransferase (ACAT), was determined in the rat liver, intestine, and white (WAT) and brown adipose tissue (BAT). Animal studies have shown that dietary manipulation of cholesterol metabolism during an animal's early development can have persistent and permanent effects. Therefore it is important that the ontogeny of ACAT, one of the key enzymes in cholesterol metabolism, be clearly established. White Wistar rats were killed on day 21 of gestation, at birth, and on postnatal days 10, 14, 18, 21, 22, 25, 30, and 60. The tissues were rapidly excised, microsomes were prepared, and the activity of ACAT was measured as the rate of incorporation of [1-14C]oleoyl coenzyme A into cholesterol esters. Age-specific changes were observed in three of the four tissues investigated. Rat liver and intestine possess significant amounts of ACAT activity throughout development with marked variations in activity during this time. ACAT activity in BAT is low and variable throughout development with the exception of high activity noted in the adult animal. WAT contained little or no ACAT activity during development.


1989 ◽  
Vol 9 (1) ◽  
pp. 83-91
Author(s):  
S Miyazawa ◽  
T Osumi ◽  
T Hashimoto ◽  
K Ohno ◽  
S Miura ◽  
...  

To identify the topogenic signal of peroxisomal acyl-coenzyme A oxidase (AOX) of rat liver, we carried out in vitro import experiments with mutant polypeptides of the enzyme. Full-length AOX and polypeptides that were truncated at the N-terminal region were efficiently imported into peroxisomes, as determined by resistance to externally added proteinase K. Polypeptides carrying internal deletions in the C-terminal region exhibited much lower import activities. Polypeptides that were truncated or mutated at the extreme C terminus were totally import negative. When the five amino acid residues at the extreme C terminus were attached to some of the import-negative polypeptides, the import activities were rescued. Moreover, the C-terminal 199 and 70 amino acid residues of AOX directed fusion proteins with two bacterial enzymes to peroxisomes. These results are interpreted to mean that the peroxisome targeting signal of AOX residues at the C terminus and the five or fewer residues at the extreme terminus have an obligatory function in targeting. The C-terminal internal region also has an important role for efficient import, possibly through a conformational effect.


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