Heppner, Thomas J., Adrian D. Bonev, L. Fernando Santana, and Mark T. Nelson. Alkaline pH shifts Ca2 sparks to Ca2 waves in smooth muscle cells of pressurized cerebral arteries. Am J Physiol Heart Circ Physiol 283: H2169–H2176, 2002; 10.1152/ajpheart.00603.2002.—The effects of external pH (7.0–8.0) on intracellular Ca2 signals (Ca2 sparks and Ca2 waves) were examined in smooth muscle cells from...

Exposure of Saccharomyces cerevisiae to alkaline pH provokes a stress condition that generates a compensatory reaction. In the present study we examined a possible role for the PKA (protein kinase A) pathway in this response. Phenotypic analysis revealed that mutations that activate the PKA pathway (ira1 ira2, bcy1) tend to cause sensitivity to alkaline pH, whereas its deactivation enhances tol...

This specific phosphatase is a 5-nucleotidase; it differs from the alkaline phosphatase in its range of action and in its optimal pH. Whereas alkaline phosphatase, which is non-specific, hydrolyses a great variety of phosphoric esters, the 5-nucleotidase hydrolyses only nucleotides with the phosphate group attached to the fifth carbon of the pentose, that is, muscle adenylic acid (adenosine-5-m...

Environmental pH induces a stress response triggering a signaling pathway whose components have been identified and characterized in several fungi. Neurospora crassa shares all six components of the Aspergillus nidulans pH signaling pathway, and we investigate here their regulation during an alkaline pH stress response. We show that the N. crassa pal mutant strains, with the exception of Δpal-9...

Fumonisins are a group of mycotoxins that contaminate maize and cause leukoencephalomalacia in equine, pulmonary edema in swine, and promote cancer in mice. Fumonisin biosynthesis in Fusarium verticillioides is repressed by nitrogen and alkaline pH. We cloned a PACC-like gene (PAC1) from F. verticillioides. PACC genes encode the major transcriptional regulators of several pH-responsive pathways...

High pH values have been found necessary for optimum activity of alkaline phosphatase in vitro. The pH values in the living cell structures, on the other hand, are near neutrality: cytoplasm 6.9, nucleus 7.6 (l-3). This definite difference between the pH required for optimum activity and the pH of the living cell indicates that alkaline phosphatase is not optimally active in viva. However, the ...

Functional coupling of calcium- and alkaline responsive signalling occurs in multiple fungi to afford efficient cation homeostasis. Host microenvironments exert alkaline stress and potentially toxic concentrations of Ca2+ , such that highly conserved regulators of both calcium- (Crz) and pH- (PacC/Rim101) responsive signalling are crucial for fungal pathogenicity. Drugs targeting calcineurin ar...

Depending on the pH of the growth medium, the yeast Yarrowia lipolytica secretes an acidic protease or an alkaline protease, the synthesis of which is also controlled by carbon, nitrogen, and sulfur availability, as well as by the presence of extracellular proteins. Previous results have indicated that the alkaline protease response to pH was dependent on YlRim101p, YlRim8p/YlPalF, and YlRim21p...

Batch tests indicated that arsenic (As) leaching is significantly affected by the calcium concentration in fly ash in the alkaline pH range. Arsenic leaching from low calcium fly ash from eastern bituminous coal increased with increase of pH in the alkaline pH range (pH 7 – 12). Fly ash from eastern bituminous coal with a slightly higher calcium content exhibited an arsenic leaching peak at pH ...