title: Adenovirus-dependent changes in cell membrane permeability: role of Na+, K+-ATPase.
abstract: Adenovirus-dependent release of choline phosphate from KB cells at pH 6.0 was partially blocked by ouabain. In K+-containing medium, maximum inhibition of release was obtained by 10(-5) M ouabain and half-maximal inhibition was achieved by about 0.5 X 10(-6)M ouabain. Ouabain did not block either the binding or the uptake of adenovirus by KB cells. Without K+, about 25% of cell-associated choline phosphate was released by adenovirus, whereas with 1 mM K+ about 50% was released. This activation by K+ was blocked by 0.1 mM ouabain. HeLa cells behaved like KB cells, but a mutant of HeLa cells resistant to ouabain (D98-OR) released much lower amounts of choline phosphate in response to human adenovirus type 2 (Ad2). Wild-type D98-OR cells bound nearly the same amount of adenovirus as did normal HeLa cells. Ad2 also increased the activity of Na+,K+-ATPase in KB cells, with maximum activation at 50 micrograms of Ad2 per ml. In D98-OR cells, Ad2 failed to activate Na+,K+-ATPase activity. Ad2-dependent lysis of endocytic vesicles (receptosomes) was assayed by measuring Ad2-dependent enhancement of epidermal growth factor-Pseudomonas exotoxin toxicity. This action of adenovirus was increased when K+ was present in the medium. Under the conditions used, K+ had no effect on the amount of Ad2 or epidermal growth factor taken up by the cells. On the basis of these results, it is suggested that Ad2-dependent cellular efflux of choline phosphate and adenovirus-dependent lysis of receptosomes may require Na+,K+-ATPase activity.
mesh_terms: D000260:Adenoviruses, Human / Q000502:physiology*; D000262:Adenylyl Cyclases / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002463:Cell Membrane Permeability; D002472:Cell Transformation, Viral; D002794:Choline / Q000378:metabolism; D011992:Endosomes / Q000502:physiology; D004789:Enzyme Activation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000502:physiology; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
chemical_list: D010042:Ouabain; D000262:Adenylyl Cyclases; D000254:Sodium-Potassium-Exchanging ATPase; D002794:Choline; D011188:Potassium