Co-induction of methyltransferase Rv0560c by naphthoquinones and fibric acids suggests attenuation of isoprenoid quinone action inMycobacterium tuberculosis

2004 ◽  
Vol 50 (10) ◽  
pp. 771-778 ◽  
Author(s):  
Thomas R Garbe
Keyword(s):  
Sequence Data ◽  
Peroxisome Proliferator ◽  
Similar Response ◽  
Terminal Sequence ◽  
Protein Patterns ◽  
Dependent Protein ◽  
Isoprenoid Quinones ◽  
Fibric Acids ◽  
Related Compounds ◽  
Sequence Similarities

The superoxide generator menadione was previously demonstrated as an inducer of growth stage dependent protein patterns in Mycobacterium tuberculosis. The present study refines this observation by characterizing a novel 27-kDa protein that had not been observed in previous studies relying on younger cultures. A very similar response, based on two-dimensional gel electrophoretic analyses, was induced by the closely related naphthoquinone plumbagin. The 27-kDa protein was also induced by the pro-oxidant peroxisome proliferator gemfibrozil and to a lesser extent by the structurally related compounds fenofibrate and clofibrate. N-terminal sequence data of proteolytic fragments from the 27-kDa protein demonstrated its identity with protein Rv0560c, previously demonstrated to be inducible by salicylate, which also possesses peroxisome proliferating properties. Protein Rv0560c bears three conserved motifs characteristic of S-adenosylmethionine-dependent methyltransferases. Further sequence similarities suggest a function in the bio syn thesis of isoprenoid compounds, e.g., tocopherol, ubiquinone, and sterols. Such involvement is supported by the recognized yet unexplained widespread interference of menadione, salicylate, and fibrates with the isoprenoid quinones ubiquinone, menaquinone, and vitamin K. Induction of Rv0560c by fibrates, salicylate, and naphthoquinones is thus suggested to be caused by action on the plasma membrane, reminiscent of cytochrome P450BM-3 induction by fibrates in Bacillus megaterium, which catalyzes the hydroxylation of fatty acids and thus modulates membrane properties.Key words: peroxisome proliferators, membrane derangement, menaquinone antagonism, respiratory inhibition.

scholarly journals Protective Effects of PGC-1α Activators on Ischemic Stroke in a Rat Model of Photochemically Induced Thrombosis

2021 ◽  
Vol 11 (3) ◽  
pp. 325
Author(s):  
Fatima M. Shakova ◽  
Yuliya I. Kirova ◽  
Denis N. Silachev ◽  
Galina A. Romanova ◽  
Sergey G. Morozov
Keyword(s):  
Rat Model ◽  
Nuclear Translocation ◽  
Peroxisome Proliferator ◽  
Protective Effects ◽  
Protein Markers ◽  
Peroxisome Proliferator Activated Receptor ◽  
Pharmacological Agents ◽  
Ischemic Brain ◽  
Neuroprotective Therapy ◽  
Dependent Protein

The pharmacological induction and activation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), a key regulator of ischemic brain tolerance, is a promising direction in neuroprotective therapy. Pharmacological agents with known abilities to modulate cerebral PGC-1α are scarce. This study focused on the potential PGC-1α-modulating activity of Mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate) and Semax (ACTH(4–7) analog) in a rat model of photochemical-induced thrombosis (PT) in the prefrontal cortex. Mexidol (100 mg/kg) was administered intraperitoneally, and Semax (25 μg/kg) was administered intranasally, for 7 days each. The expression of PGC-1α and PGC-1α-dependent protein markers of mitochondriogenesis, angiogenesis, and synaptogenesis was measured in the penumbra via immunoblotting at Days 1, 3, 7, and 21 after PT. The nuclear content of PGC-1α was measured immunohistochemically. The suppression of PGC-1α expression was observed in the penumbra from 24 h to 21 days following PT and reflected decreases in both the number of neurons and PGC-1α expression in individual neurons. Administration of Mexidol or Semax was associated with preservation of the neuron number and neuronal expression of PGC-1α, stimulation of the nuclear translocation of PGC-1α, and increased contents of protein markers for PGC-1α activation. This study opens new prospects for the pharmacological modulation of PGC-1α in the ischemic brain.

scholarly journals Deletion of CaMKK2 from the Liver Lowers Blood Glucose and Improves Whole-Body Glucose Tolerance in the Mouse

2012 ◽  
Vol 26 (2) ◽  
pp. 281-291 ◽  
Author(s):  
Kristin A. Anderson ◽  
Fumin Lin ◽  
Thomas J. Ribar ◽  
Robert D. Stevens ◽  
Michael J. Muehlbauer ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Protein Kinase ◽  
Glucose Tolerance ◽  
Glucose Intolerance ◽  
De Novo Lipogenesis ◽  
Whole Body ◽  
Peroxisome Proliferator ◽  
Dependent Protein Kinase ◽  
Peroxisome Proliferator Activated Receptor ◽  
Dependent Protein

Abstract Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) is a member of the Ca2+/CaM-dependent protein kinase family that is expressed abundantly in brain. Previous work has revealed that CaMKK2 knockout (CaMKK2 KO) mice eat less due to a central nervous system -signaling defect and are protected from diet-induced obesity, glucose intolerance, and insulin resistance. However, here we show that pair feeding of wild-type mice to match food consumption of CAMKK2 mice slows weight gain but fails to protect from diet-induced glucose intolerance, suggesting that other alterations in CaMKK2 KO mice are responsible for their improved glucose metabolism. CaMKK2 is shown to be expressed in liver and acute, specific reduction of the kinase in the liver of high-fat diet-fed CaMKK2floxed mice results in lowered blood glucose and improved glucose tolerance. Primary hepatocytes isolated from CaMKK2 KO mice produce less glucose and have decreased mRNA encoding peroxisome proliferator-activated receptor γ coactivator 1-α and the gluconeogenic enzymes glucose-6-phosphatase and phosphoenolpyruvate carboxykinase, and these mRNA fail to respond specifically to the stimulatory effect of catecholamine in a cell-autonomous manner. The mechanism responsible for suppressed gene induction in CaMKK2 KO hepatocytes may involve diminished phosphorylation of histone deacetylase 5, an event necessary in some contexts for derepression of the peroxisome proliferator-activated receptor γ coactivator 1-α promoter. Hepatocytes from CaMKK2 KO mice also show increased rates of de novo lipogenesis and fat oxidation. The changes in fat metabolism observed correlate with steatotic liver and altered acyl carnitine metabolomic profiles in CaMKK2 KO mice. Collectively, these results are consistent with suppressed catecholamine-induced induction of gluconeogenic gene expression in CaMKK2 KO mice that leads to improved whole-body glucose homeostasis despite the presence of increased hepatic fat content.

scholarly journals Microbial Dextran-Hydrolyzing Enzymes: Fundamentals and Applications

2005 ◽  
Vol 69 (2) ◽  
pp. 306-325 ◽  
Author(s):  
Elvira Khalikova ◽  
Petri Susi ◽  
Timo Korpela
Keyword(s):  
Sequence Data ◽  
Three Dimensional ◽  
Side Reaction ◽  
Sequence Information ◽  
New Classification ◽  
Wide Range ◽  
Hydrolyzing Enzymes ◽  
Complex Polymer ◽  
Sequence Similarities ◽  
Primary Sequence Data

SUMMARY Dextran is a chemically and physically complex polymer, breakdown of which is carried out by a variety of endo- and exodextranases. Enzymes in many groups can be classified as dextranases according to function: such enzymes include dextranhydrolases, glucodextranases, exoisomaltohydrolases, exoisomaltotriohydrases, and branched-dextran exo-1,2-α-glucosidases. Cycloisomalto-oligosaccharide glucanotransferase does not formally belong to the dextranases even though its side reaction produces hydrolyzed dextrans. A new classification system for glycosylhydrolases and glycosyltransferases, which is based on amino acid sequence similarities, divides the dextranases into five families. However, this classification is still incomplete since sequence information is missing for many of the enzymes that have been biochemically characterized as dextranases. Dextran-degrading enzymes have been isolated from a wide range of microorganisms. The major characteristics of these enzymes, the methods for analyzing their activities and biological roles, analysis of primary sequence data, and three-dimensional structures of dextranases have been dealt with in this review. Dextranases are promising for future use in various scientific and biotechnological applications.

Transcriptional regulation of temperature-induced remodeling of muscle bioenergetics in goldfish

2012 ◽  
Vol 303 (2) ◽  
pp. R150-R158 ◽  
Author(s):  
Katharina Bremer ◽  
Christopher T. Monk ◽  
Brendon J. Gurd ◽  
Christopher D. Moyes
Keyword(s):  
Dna Binding ◽  
Mitochondrial Biogenesis ◽  
Binding Proteins ◽  
Nuclear Protein ◽  
Transcriptional Response ◽  
Dna Binding Proteins ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Protein Patterns ◽  
Peroxisome Proliferator Activated Receptor

Central to mammalian mitochondrial biogenesis is the transcriptional master regulator peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), and a network of DNA-binding proteins it coactivates. We explored the role of this pathway in muscle mitochondrial biogenesis in response to thermal acclimation in goldfish ( Carassius auratus ). We investigated the transcriptional response of PGC-1α, PGC-1β, and their antagonist the nuclear receptor interacting protein 1 ( RIP140), as well as the mRNA and protein patterns of DNA-binding proteins that bind PGC-1, including nuclear respiratory factors (NRF) 1 and 2, retinoid X receptor α (RXRα), estrogen-related receptor α (ERRα), thyroid receptor α-1 (TRα-1), PPARα, and PPARβ/δ, and the host cell factor 1 (HCF1), which links PGC-1 and NRF-2. Cold-acclimated (4°C) fish had higher COX activities (4.5-fold) and COX4-1 mRNA levels (3.5-fold per total RNA; 6.5-fold per gram tissue) than warm-acclimated (32°C) fish. The transcription factor patterns were profoundly influenced by changes in RNA per gram tissue (2-fold higher in cold fish) and nuclear protein content (2-fold higher in warm fish). In cold-acclimated fish, mRNA per gram tissue was elevated for PGC-1β, RIP140, NRF-1, HCF1, NRF-2α, NRF-2β-2, ERRα, PPAR β/δ, and RXRα, but other transcriptional regulators either did not change ( PGC-1α, PPARα) or even decreased ( TRα-1). Nuclear protein levels in cold-acclimated fish were higher only for NRF-1; other proteins were either unaffected (NRF-2α, ERRα) or decreased (NRF-2β1/2, TRα, RXRα). Collectively, these data support the role for NRF-1 in regulating cold-induced mitochondrial biogenesis in goldfish, with effects mediated by PGC-1β, rather than PGC-1α.

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