Troponin T (TnT) is an essential protein in the Ca2+ regulatory system of striated of muscle. Three fiber type-specific TnT genes have evolved in higher vertebrates to encode cardiac, slow and fast skeletal muscle TnT isoforms. To understand the functional significance of TnT isoforms, we studied the effects of acidosis on the contractility of transgenic mouse cardiac muscle that expresses fast...

A Glu139Asp mutant of the NtpK subunit (kE139D) of Enterococcus hirae vacuolar-type ATPase (V-ATPase) lost tolerance to sodium but not to lithium at pH 10. Purified kE139D V-ATPase retained relatively high specific activity and affinity for the lithium ion compared to the sodium ion. The kE139 residue of V-ATPase is indispensable for its enzymatic activity that is linked with the salt tolerance...

We studied the relationship between the use of three detoxification pathways and urine pH and the tolerance of desert woodrats from two populations to a mixture of naturally occurring plant secondary metabolites (mostly phenolics) in resin from creosote bush (Larrea tridentata). The two populations of desert woodrats came from the Mojave desert (Mojave woodrats), where woodrats consume creosote...

Excess acetate has long been an issue for the production of recombinant proteins in E. coli cells. Recently, improvements in acetate tolerance have been achieved through the use of genetic strategies and medium supplementation with certain amino acids and pyrimidines. The aim of our study was to evaluate an alternative to improve the acetate tolerance of E. coli BL21 (DE3), a popular strain use...

Corals are acclimatized to populate dynamic habitats that neighbour coral reefs. Habitats such as seagrass beds exhibit broad diel changes in temperature and pH that routinely expose corals to conditions predicted for reefs over the next 50-100 years. However, whether such acclimatization effectively enhances physiological tolerance to, and hence provides refuge against, future climate scenario...

Responses of Melaleuca leucadendra (L.) L., Melaleuca cajuputi Powell, Acacia auriculiformis A. Cunn. ex Benth. and Eucalyptus camaldulensis Dehnh. to aluminum (Al) toxicity at low pH are poorly understood. We investigated effects of low pH and exudation of ligands by roots on Al tolerance of these species. Seedlings were grown hydroponically in nutrient solutions at pH 4.2 or 3.5 containing Al...

For several foodborne bacterial pathogens, an acid tolerance response appears to be an important strategy for counteracting acid stress imposed either during food processing or by the human host. The acid tolerance response enhances bacterial survival of lethal acid challenge following prior exposure to sublethal acidic conditions. Previous studies have revealed relationships between a foodborn...

Ocean acidification is the increase in seawater pCO 2 due to the uptake of atmospheric anthropogenic CO 2, with the largest changes predicted to occur in the Arctic seas. For some marine organisms, this change in pCO 2, and associated decrease in pH, represents a climate change-related stressor. In this study, we investigated the gene expression patterns of nauplii of the Arctic copepod Calanus...

The present study investigated the possible antiobesity and hypoglycemic effects of phloretin (Ph). In an attempt to discover the hypoglycemic effect and potential mechanism of Ph, we used the streptozotocin-induced diabetic rats and (L6) myotubes. Daily oral treatment with Ph for 4 weeks significantly (P<0.05) reduced postprandial blood glucose and improved islet injury and lipid metabolism. G...

Soil alkalization triggers ion toxicity and osmotic alkaline (high pH) stresses in plants, damaging their growth productivity. Therefore, we investigated whether priming with abscisic acid (ABA) increases the tolerance of alfalfa seedlings to stress, then examined underlying molecular mechanisms. Alfalfa were pretreated ABA (10 μM) for 16 h subjected stress using a 15 mM Na2CO3 solution (pH 10....