The mitochondrial phosphate transporter (MPT) plays crucial roles in ATP production in plant cells. Three MPT genes have been identified in Arabidopsis thaliana. Here we report that the mRNA accumulations of AtMPTs were up-regulated by high salinity stress in A. thaliana seedlings. And the transgenic lines overexpressing AtMPTs displayed increased sensitivity to salt stress compared with the wi...

Introduction: Gene expression and purification of luciferases from the firefly, Lampyris turkestanicus, and optimization of cellular ATP measurements were performed. Methods: cDNA encoding luciferases from Lampyris turkestanicus was transferred from pQE30 vector into pET28a expression vector and pLtu28 was built. Newly constructed vector was expressed in E. coli XL1 Blue and the recombinant l...

Mouse beta-cells cultured at 15 mmol/l glucose for 72 h had reduced ATP-sensitive K+ (K(ATP)) channel activity (-30%), increased voltage-gated Ca2+ currents, higher intracellular free Ca2+ concentration ([Ca2+]i; +160%), more exocytosis (monitored by capacitance measurements, +100%), and greater insulin content (+230%) than those cultured at 4.5 mmol/l glucose. However, they released 20% less i...

Methane formation from acetate by resting cells of Methanosarcina barkeri was accompanied by an increase in the intracellular ATP content from 0.9 to 4.0 nmol/mg of protein. Correspondingly, the proton motive force increased to a steady-state level of -120 mV. The transmembrane pH gradient however, was reversed under these conditions and amounted to +20 mV. The addition of the protonophore 3,5,...

A steroidal glycoside with anorectic activity in animals, termed P57AS3 (P57), was isolated from Hoodia gordonii and found to have homologies to the steroidal core of cardiac glycosides. Intracerebroventricular (i.c.v.) injections of the purified P57AS3 demonstrated that the compound has a likely central (CNS) mechanism of action. There is no evidence of P57AS3 binding to or altering activity o...

Effects of respiratory inhibitors on the circadian clock, respiratory activity, and ATP content were examined in Neurospora crassa. All inhibitors, potassium cyanide, sodium azide, antimycin A, and carbonyl cyanide m-chlorophenyl hydrazone (CCCP), shifted the phase of the conidiation rhythm. All the phase response curves were similar and resembled that for cycloheximide, but were different from...

In insulin-producing cells of the RINm5F line, the nonmetabolized analogue of L-leucine, 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid decreases O2 consumption, lowers ATP content, and inhibits insulin release despite stimulation of both NH4 production and 14CO2 output from cells prelabeled with L-[U-14C]glutamine. The metabolic and secretory effects of 2-aminobicyclo[2,2,1]heptane-2-carboxyli...

Electrical shock treatment produces a rapid loss of high energy phosphates in rat brain. The [ATP]/[ADP] ratio decreases to one-third of its control value within 10 s. The ammonia content increases 3-fold during the first minute after starting the stimulus. The total adenine nucleotide plus adenosine content of brain decreases an equivalent amount of hypoxanthine-containing compounds appears. A...

The ratio of ATP content/ADP content in livers from unanaesthetized fed rat was 0.9 in the mitochondrial matrix and 6.9 in the cytosol; the values for starved (48 h) animals were 1.0 and 5.9 respectively. The mitochondrial ratios observed in unanaesthetized animals were higher than in haemoglobin-free-perfused liver and lower than in isolated hepatocytes. Possible reasons for these differences ...

Maternally inherited mitochondrial DNA (mtDNA) has been suggested to be a genetic factor for diabetes. Reports have shown a decrease of mtDNA content in tissues of diabetic patients. We investigated the effects of mtDNA depletion on glucose metabolism by use of rho(0) SK-Hep1 human hepatoma cells, whose mtDNA was depleted by long-term exposure to ethidium bromide. The rho(0) cells failed to hyp...