Characterization of Plasma Membrane ATPase Purified by Phase Partitioning from Sunflower Roots

1989 ◽  
Vol 185 (3-4) ◽  
pp. 181-187 ◽  
Author(s):  
A. Szabó-Nagy ◽  
A. Bérczi
Keyword(s):  
Plasma Membrane ◽  
Plasma Membrane Atpase ◽  
Phase Partitioning ◽  
Membrane Atpase

scholarly journals Secretory vesicles externalize the major plasma membrane ATPase in yeast.

1988 ◽  
Vol 106 (3) ◽  
pp. 641-648 ◽  
Author(s):  
C L Holcomb ◽  
W J Hansen ◽  
T Etcheverry ◽  
R Schekman
Keyword(s):  
Plasma Membrane ◽  
Secretory Pathway ◽  
Biochemical Characterization ◽  
Plasma Membrane Atpase ◽  
Membrane Assembly ◽  
Yeast Cell Surface ◽  
Membrane Atpase ◽  
Constitutive Secretion ◽  
Secretory Enzyme

Yeast cell surface growth is accomplished by constitutive secretion and plasma membrane assembly, culminating in the fusion of vesicles with the bud membrane. Coordination of secretion and membrane assembly has been investigated by examining the biogenesis of plasma membrane ATPase (PM ATPase) in secretion-defective (sec) strains of Saccharomyces cerevisiae. PM ATPase is synthesized as a approximately 106-kD polypeptide that is not detectably modified by asparagine-linked glycosylation or proteolysis during transit to the plasma membrane. Export of the PM ATPase requires the secretory pathway. In sec1, a mutant defective in the last step of secretion, large amounts of Golgi-derived vesicles are accumulated. Biochemical characterization of this organelle has demonstrated that PM ATPase and the secretory enzyme, acid phosphatase, are transported in a single vesicle species.

PLASMA MEMBRANE ATPASE ISOLATED FROM GREEN BELL PEPPER FRUIT BY TWO-PHASE PARTITIONING OR SUCROSE DENSITY GRADIENT

1994 ◽  
Vol 42 (1) ◽  
pp. 15-27
Author(s):  
R. Ronen ◽  
Z. Lipsker ◽  
L. Sonego ◽  
Susan Lurie
Keyword(s):  
Plasma Membrane ◽  
Density Gradient ◽  
Sucrose Density Gradient ◽  
Bell Pepper ◽  
Phase System ◽  
Plasma Membrane Atpase ◽  
Two Phase ◽  
Phase Partitioning ◽  
Pepper Fruit ◽  
Membrane Atpase

Plasma membrane was isolated from mature green bell pepper fruit by two-phase partitioning or by sucrose density gradient. The yield of plasma membrane was higher from the sucrose density gradient, but the two-phase system was less contaminated by other membranes, particularly those from chloroplasts and mitochondria. In the two-phase partitioned membranes, ATPase activity was stimulated by Triton X-100 by 100% and in sucrose density gradient membranes by 40%. Plasma membranes from two-phase partitioning exhibited simultaneous proton pumping and ATP hydrolysis, while the sucrose density purified membranes did not. Immunoblotting with ATPase antibody showed enrichment of plasma membrane ATPase in both the U3 phase of the two-phase system, and the 34% sucrose fraction of the sucrose gradient. However, the two-phase partitioned membranes were superior to those prepared by sucrose density for investigating functions of the ATPase.

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