منابع مشابه
Regulation of cytoplasmic pH in bacteria.
In the last 30 years, bacteria have provided experimentalists with an easily manipulable system in which to study regulatory phenomena. This has led to a relatively clear understanding of the regulatory mechanisms which operate to control gene expression (35). However, with a few exceptions (e.g., chemotaxis, the control of enzyme activity) regulatory phenomena which primarily involve control o...
متن کاملCytoplasmic pH measurement and homeostasis in bacteria and archaea.
Of all the molecular determinants for growth, the hydronium and hydroxide ions are found naturally in the widest concentration range, from acid mine drainage below pH 0 to soda lakes above pH 13. Most bacteria and archaea have mechanisms that maintain their internal, cytoplasmic pH within a narrower range than the pH outside the cell, termed "pH homeostasis." Some mechanisms of pH homeostasis a...
متن کاملCytoplasmic pH regulation and chloride/bicarbonate exchange in avian osteoclasts.
Osteoclasts resorb bone by first attaching to the bone surface and then secreting protons into an isolated extracellular compartment formed at the cell-bone attachment site. This secretion of protons (local acidification) is required to solubilize bone hydroxyapatite crystals and for activity of bone collagen-degrading acid proteases. However, the large quantity of protons required, 2 mol/mol o...
متن کاملRole of "active" potassium transport in the regulation of cytoplasmic pH by nonanimal cells.
High-affinity potassium uptake in Neurospora occurs by symport with protons [Km (apparent) = 15 microM at pH 5.8], for which a large inward gradient (approximately 400 mV) is generated by the H+-extruding ATPase of the plasma membrane. Operating in parallel, the two transport systems yield a net 1:1 exchange of K+ for cytoplasmic H+. Since this exchange could play a role in cytoplasmic pH (pHi)...
متن کاملRegulation of Cytoplasmic and Vacuolar pH in Maize Root Tips under Different Experimental Conditions.
(31)P-Nuclear magnetic resonance spectra of perfused maize (Zea mays L., hybrid WW x Br 38) root tips, obtained at 10-minute intervals over 12 hours or longer, indicate that no cytoplasmic or vacuolar pH changes occur in these cells in the presence of 25 millimolar K(2)SO(4), which induces extrusion of 4 to 5 microequivalents H(+) per gram per hour. In contrast, hypoxia causes cytoplasmic acidi...
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ژورنال
عنوان ژورنال: Microbiological Reviews
سال: 1985
ISSN: 0146-0749
DOI: 10.1128/mr.49.4.359-378.1985