Studies on the Reaction Mechanism and Transport Function of P-type ATPases Associated with the Plant Plasma Membrane

1992 ◽  
pp. 13-24 ◽  
Author(s):  
Donald P. Briskin ◽  
Swati Basu ◽  
InSun Ho
Keyword(s):  
Plasma Membrane ◽  
Reaction Mechanism ◽  
Transport Function ◽  
P Type ◽  
Plant Plasma Membrane

scholarly journals In vivo cross-linking supports a head-to-tail mechanism for regulation of the plant plasma membrane P-type H+-ATPase

2018 ◽  
Vol 293 (44) ◽  
pp. 17095-17106 ◽  
Author(s):  
Thao T. Nguyen ◽  
Grzegorz Sabat ◽  
Michael R. Sussman
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Unnatural Amino Acid ◽  
Proton Pumping ◽  
Intramolecular Interactions ◽  
Cross Linking ◽  
Regulatory Domain ◽  
P Type ◽  
Plant Plasma Membrane

In higher plants, a P-type proton-pumping ATPase generates the proton-motive force essential for the function of all other transporters and for proper growth and development. X-ray crystallographic studies of the plant plasma membrane proton pump have provided information on amino acids involved in ATP catalysis but provided no information on the structure of the C-terminal regulatory domain. Despite progress in elucidating enzymes involved in the signaling pathways that activate or inhibit this pump, the site of interaction of the C-terminal regulatory domain with the catalytic domains remains a mystery. Genetic studies have pointed to amino acids in various parts of the protein that may be involved, but direct chemical evidence for which ones are specifically interacting with the C terminus is lacking. In this study, we used in vivo cross-linking experiments with a photoreactive unnatural amino acid, p-benzoylphenylalanine, and tandem MS to obtain direct evidence that the C-terminal regulatory domain interacts with amino acids located within the N-terminal actuator domain. Our observations are consistent with a mechanism in which intermolecular, rather than intramolecular, interactions are involved. Our model invokes a “head-to-tail” organization of ATPase monomers in which the C-terminal domain of one ATPase molecule interacts with the actuator domain of another ATPase molecule. This model serves to explain why cross-linked peptides are found only in dimers and trimers, and it is consistent with prior studies suggesting that within the membrane the protein can be organized as homopolymers, including dimers, trimers, and hexamers.

scholarly journals Putative PmrA and PmcA are important for normal growth, morphogenesis and cell wall integrity, but not for viability in Aspergillus nidulans

Microbiology ◽  
2014 ◽  
Vol 160 (11) ◽  
pp. 2387-2395 ◽  
Author(s):  
Hechun Jiang ◽  
Feifei Liu ◽  
Shizhu Zhang ◽  
Ling Lu
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Aspergillus Nidulans ◽  
Normal Growth ◽  
Cell Wall Integrity ◽  
Plasma Membrane Atpase ◽  
Growth Defects ◽  
Double Deletion ◽  
Intracellular Ca ◽  
P Type

P-type Ca2+-transporting ATPases are Ca2+ pumps, extruding cytosolic Ca2+ to the extracellular environment or the intracellular Ca2+ store lumens. In budding yeast, Pmr1 (plasma membrane ATPase related), and Pmc1 (plasma membrane calcium-ATPase) cannot be deleted simultaneously for it to survive in standard medium. Here, we deleted two putative Ca2+ pumps, designated AnPmrA and AnPmcA, from Aspergillus nidulans, and obtained the mutants ΔanpmrA and ΔanpmcA, respectively. Then, using ΔanpmrA as the starting strain, the promoter of its anpmcA was replaced with the alcA promoter to secure the mutant ΔanpmrAalcApmcA or its anpmcA was deleted completely to produce the mutant ΔanpmrAΔpmcA. Different from the case in Saccharomyces cerevisiae, double deletion of anpmrA and anpmcA was not lethal in A. nidulans. In addition, deletion of anpmrA and/or anpmcA had produced growth defects, although overexpression of AnPmc1 in ΔanpmrAalcApmcA could not restore the growth defects that resulted from the loss of AnPmrA. Moreover, we found AnPmrA was indispensable for maintenance of normal morphogenesis, especially in low-Ca2+/Mn2+ environments. Thus, our findings suggest AnPmrA and AnPmcA might play important roles in growth, morphogenesis and cell wall integrity in A. nidulans in a different way from that in yeasts.

Terminal Enzymes of Heme Biosynthesis in the Plant Plasma Membrane

1995 ◽  
Vol 323 (2) ◽  
pp. 274-278 ◽  
Author(s):  
Judith M. Jacobs ◽  
Nicholas J. Jacobs
Keyword(s):  
Plasma Membrane ◽  
Heme Biosynthesis ◽  
Plant Plasma Membrane

scholarly journals Structure of a 14-3-3 Coordinated Hexamer of the Plant Plasma Membrane H+-ATPase by Combining X-Ray Crystallography and Electron Cryomicroscopy

2007 ◽  
Vol 25 (3) ◽  
pp. 427-440 ◽  
Author(s):  
Christian Ottmann ◽  
Sergio Marco ◽  
Nina Jaspert ◽  
Caroline Marcon ◽  
Nicolas Schauer ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Electron Cryomicroscopy ◽  
X Ray ◽  
X Ray Crystallography ◽  
Plant Plasma Membrane

scholarly journals Cross Talk between Sphingolipids and Glycerophospholipids in the Establishment of Plasma Membrane Asymmetry

2004 ◽  
Vol 15 (11) ◽  
pp. 4949-4959 ◽  
Author(s):  
Akio Kihara ◽  
Yasuyuki Igarashi
Keyword(s):  
Plasma Membrane ◽  
Cross Talk ◽  
Abc Transporters ◽  
Transcriptional Factor ◽  
Drug Efflux ◽  
Lipid Asymmetry ◽  
Membrane Asymmetry ◽  
P Type ◽  
Yeast Mutants ◽  
Long Chain

Glycerophospholipids and sphingolipids are distributed asymmetrically between the two leaflets of the lipid bilayer. Recent studies revealed that certain P-type ATPases and ATP-binding cassette (ABC) transporters are involved in the inward movement (flip) and outward movement (flop) of glycerophospholipids, respectively. In this study of phytosphingosine (PHS)-resistant yeast mutants, we isolated mutants for PDR5, an ABC transporter involved in drug efflux as well as in the flop of phosphatidylethanolamine. The pdr5 mutants exhibited an increase in the efflux of sphingoid long-chain bases (LCBs). Genetic analysis revealed that the PHS-resistant phenotypes exhibited by the pdr5 mutants were dependent on Rsb1p, a putative LCB-specific transporter/translocase. We found that the expression of Rsb1p was increased in the pdr5 mutants. We also demonstrated that expression of RSB1 is under the control of the transcriptional factor Pdr1p. Expression of Rsb1p also was enhanced in mutants for the genes involved in the flip of glycerophospholipids, including ROS3, DNF1, and DNF2. These results suggest that altered glycerophospholipid asymmetry induces the expression of Rsb1p. Conversely, overexpression of Rsb1p resulted in increased flip and decreased flop of fluorescence-labeled glycerophospholipids. Thus, there seems to be cross talk between sphingolipids and glycerophospholipids in maintaining the functional lipid asymmetry of the plasma membrane.

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