scholarly journals Ultrastructural localizations of adenosine triphosphatase activity in resting mammary gland.

1977 ◽  
Vol 25 (2) ◽  
pp. 135-148 ◽  
Author(s):  
J Russo ◽  
P Wells
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Plasma Membranes ◽  
Ultrastructural Level ◽  
Mammary Glands ◽  
Myoepithelial Cells ◽  
Mammary Tissue ◽  
Plasma Membrane Atpase ◽  
Membrane Atpase

Adenosine triphosphatase (ATPase) activity was localized at an ultrastructural level in the resting mammary glands of female BALB/c mice. A Mg++ dependent ATPase was localized in the plasma membranes of both the epithelial and myoepithelial cells of the mammary tubules. A second type of ATPase activity that was not Mg++-dependent but that was Na+ and K+ dependent was localized primarily in the plasma membranes of the myoepithelial cells. Preincubation with either ouabain or N-ethylmaleimide decreased the quantity of reaction product, indicating that both types of ATPase activity were sensitive to these inhibitors. Control media, containing adenosine triphosphate and Pb(NO3)2 without cations, demonstrated that the amount of nonezymatic hydrolysis was negligible. These differences in the cationic requirements for plasma membrane ATPase activity can be used to distinguish histochemically the epithelial from myoepithelial cells in mammary tissue.

Effects of different salts on the plasma membrane ATPase and on proton transport in yeast

1984 ◽  
Vol 62 (10) ◽  
pp. 998-1005 ◽  
Author(s):  
Jan Ahlers
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Atpase Activity ◽  
Proton Transport ◽  
Plasma Membranes ◽  
Minor Effect ◽  
Plasma Membrane Atpase ◽  
Fluorescence Quench ◽  
Membrane Atpase ◽  
Stimulation Of

The effect of various inorganic and organic salts on the plasma membrane ATPase from the yeast Saccharomyces cerevisiae and on its proton transport were studied. We observed up to 460% stimulation of ATPase activity depending on the type of salt. The anion had a major effect and the monovalent cation a minor effect. These activations were the consequence of an increase in the affinity of the ATPase for activating Mg2+ ions and of an enhancement of Vmax. The mechanism of the reaction between enzyme, substrate, and Mg2+ ions was not altered by these salts. Similary, several salts stimulated the proton transport through the plasma membranes of Saccharomyces cerevisiae as evidenced by fluorescence quench of the dye 9-amino-6-chloro-2-methoxyacridine in plasma membrane vesicles. It is proposed that this effect is due to a stimulation of ATPase activity and in addition to charge compensation by membrane permeating anions.

Change in plasma membrane ATPase activity during dormancy release of vegetative peach-tree buds

1999 ◽  
Vol 106 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Henri-Luc Aue ◽  
Isabelle Lecomte ◽  
Michel Gendraud ◽  
Gilles Pétel
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Dormancy Release ◽  
Peach Tree ◽  
Plasma Membrane Atpase ◽  
Membrane Atpase

Direct Action of Insulin on Plasma Membrane ATPase Activity in Human Lymphocytes

1972 ◽  
Vol 235 (58) ◽  
pp. 174-177 ◽  
Author(s):  
JOHN W. HADDEN ◽  
ELBA M. HADDEN ◽  
EDWIN E. WILSON ◽  
ROBERT A. GOOD ◽  
RONALD G. COFFEY
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Direct Action ◽  
Human Lymphocytes ◽  
Plasma Membrane Atpase ◽  
Membrane Atpase

Vanadate-resistant mutants of Saccharomyces cerevisiae show alterations in protein phosphorylation and growth control

1990 ◽  
Vol 10 (3) ◽  
pp. 898-909
Author(s):  
C Kanik-Ennulat ◽  
N Neff
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Atpase Activity ◽  
Protein Phosphorylation ◽  
Growth Control ◽  
Plasma Membrane Atpase ◽  
Membrane Atpase ◽  
Resistant Mutants ◽  
Diploid Cells

This work describes two spontaneous vanadate-resistant mutants of Saccharomyces cerevisiae with constitutive alterations in protein phosphorylation, growth control, and sporulation. Vanadate has been shown by a number of studies to be an efficient competitor of phosphate in biochemical reactions, especially those that involve phosphoproteins as intermediates or substrates. Resistance to toxic concentrations of vanadate can arise in S. cerevisiae by both recessive and dominant spontaneous mutations in a large number of loci. Mutations in two of the recessive loci, van1-18 and van2-93, resulted in alterations in the phosphorylation of a number of proteins. The mutant van1-18 gene also showed an increase in plasma membrane ATPase activity in vitro and a lowered basal phosphatase activity under alkaline conditions. Cells containing the van2-93 mutant allele had normal levels of plasma membrane ATPase activity, but this activity was not inhibited by vanadate. Both of these mutants failed to enter stationary phase, were heat shock sensitive, showed lowered long-term viability, and sporulated on rich medium in the presence of 2% glucose. The wild-type VAN1 gene was isolated and sequenced. The open reading frame predicts a protein of 522 amino acids, with no significant homology to any genes that have been identified. Diploid cells that contained two mutant alleles of this gene demonstrated defects in spore viability. These data suggest that the VAN1 gene product is involved in regulation of the phosphorylation of a number of proteins, some of which appear to be important in cell growth control.

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