Mechanismus der cis- und trans-Stimulierung der Anionenfluxe durch die Plasmamembran der Pflanzenzelle / Mechanism of Cis- and Trans-Stimulation of Anion Fluxes across the Plasma Membrane of Plant Cells

1970 ◽  
Vol 25 (6) ◽  
pp. 631-636 ◽  
Author(s):  
Josef Weigl
Keyword(s):  
Plasma Membrane ◽  
Permeability Coefficient ◽  
Electrical Potential ◽  
Plant Cells ◽  
Monovalent Cations ◽  
Trans Effect ◽  
Anion Permeation ◽  
Ion Efflux ◽  
Cis And Trans ◽  
Stimulation Of

Trans-stimulation by salts of the passive efflux of Cl⊖ across the plasma membrane of plant cells was established previously. In this paper the trans-effect of salts is compared with the effect of nystatin on ion efflux. It is further shown that the influx of anions is also stimulated by external salts. Influx of Cl⊖ was stimulated by K2SO4 (>~1 mM), influx of SO42⊖ was stimulated by KCl (>~lmM). This suggests that with increasing external salt concentration not only the electrical potential across the plasmalemma is lowered (due to preferential permeability to monovalent cations) but alsoth e permeability (i. e. the permeability coefficient) of the plasmalemma to anions is increased. According to the model proposed for the salt-stimulated decrease in the resistance to passive anion permeation the plasmalemma may be considered a lipid lattice-electrofilter. The nature of the coupling of the counter fluxes is discussed.

scholarly journals Concanavalin A causes an increase in sodium permeability and intracellular sodium content of pig lymphocytes

1983 ◽  
Vol 210 (3) ◽  
pp. 893-897 ◽  
Author(s):  
S M Felber ◽  
M D Brand
Keyword(s):  
Plasma Membrane ◽  
Membrane Potential ◽  
Concanavalin A ◽  
Permeability Coefficient ◽  
Sodium Content ◽  
Intracellular Sodium ◽  
Resting Cells ◽  
Sodium Permeability ◽  
Induced Changes ◽  
Stimulation Of

1. The 3mV depolarization of pig lymphocytes observed within 2 1/2 min of treatment with concanavalin A [Felber & Brand (1983) Biochem. J. 210, 885-891] is dependent on the presence of high extracellular [Na+]. 2. The concanavalin A-induced changes in membrane potential at high and low extracellular [Na+] are quantitatively explained by an increase in the electrogenic permeability coefficient for Na+ (PNa). This rises from a negligible value in resting cells to around 4% of the permeability coefficient for K+ or Cl- in stimulated cells. 3. Concanavalin A induces a 4mM increase in the Na+ content of pig lymphocytes. This increase in intracellular [Na+] is not due solely to stimulation of electrogenic Na+ influx resulting from the rise in PNa. 4. Thus concanavalin A stimulates both an electrogenic pathway for Na+ influx, resulting in a small depolarization of the plasma membrane, and a non-electrogenic Na+ influx pathway, resulting in a rise in intracellular [Na+].

Enrichment of vitronectin- and fibronectin-like proteins in NaCI-adapted plant cells and evidence for their involvement in plasma membrane-cell wall adhesion

1993 ◽  
Vol 3 (5) ◽  
pp. 637-646 ◽  
Author(s):  
Jian-Kang Zhu ◽  
Jun Shi ◽  
Utpal Singh ◽  
Sarah E. Wyatt ◽  
Ray A. Bressan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells ◽  
Membrane Cell

scholarly journals Fig mosaic emaravirus p4 protein is involved in cell-to-cell movement

2013 ◽  
Vol 94 (3) ◽  
pp. 682-686 ◽  
Author(s):  
Kazuya Ishikawa ◽  
Kensaku Maejima ◽  
Ken Komatsu ◽  
Osamu Netsu ◽  
Takuya Keima ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Laser Scanning ◽  
Movement Protein ◽  
Rna Virus ◽  
Cell Movement ◽  
Plant Cells ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Series Of Experiments ◽  
Fig Mosaic Virus

Fig mosaic virus (FMV), a member of the newly formed genus Emaravirus, is a segmented negative-strand RNA virus. Each of the six genomic FMV segments contains a single ORF: that of RNA4 encodes the protein p4. FMV-p4 is presumed to be the movement protein (MP) of the virus; however, direct experimental evidence for this is lacking. We assessed the intercellular distribution of FMV-p4 in plant cells by confocal laser scanning microscopy and we found that FMV-p4 was localized to plasmodesmata and to the plasma membrane accompanied by tubule-like structures. A series of experiments designed to examine the movement functions revealed that FMV-p4 has the capacity to complement viral cell-to-cell movement, prompt GFP diffusion between cells, and spread by itself to neighbouring cells. Altogether, our findings demonstrated that FMV-p4 shares several properties with other viral MPs and plays an important role in cell-to-cell movement.

Stimulation of Tumor-Specific Immunity Using Tumor Cell Plasma Membrane Antigen

Methods ◽  
1997 ◽  
Vol 12 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Matthew F Mescher ◽  
Elena Savelieva
Keyword(s):  
Plasma Membrane ◽  
Tumor Cell ◽  
Cell Plasma Membrane ◽  
Specific Immunity ◽  
Cell Plasma ◽  
Stimulation Of

scholarly journals Redistribution of alpha-granules and their contents in thrombin-stimulated platelets.

1984 ◽  
Vol 98 (2) ◽  
pp. 748-760 ◽  
Author(s):  
P E Stenberg ◽  
M A Shuman ◽  
S P Levine ◽  
D F Bainton
Keyword(s):  
Plasma Membrane ◽  
Tannic Acid ◽  
Extracellular Space ◽  
Plasma Membranes ◽  
Platelet Factor 4 ◽  
Platelet Factor ◽  
Thin Sections ◽  
Immunocytochemical Techniques ◽  
Morphologic Changes ◽  
Stimulation Of

The redistribution of beta-thromboglobulin (beta TG), platelet Factor 4 (PF4), and fibrinogen from the alpha granules of the platelet after stimulation with thrombin was studied by morphologic and immunocytochemical techniques. The use of tannic acid stain and quick-freeze techniques revealed several thrombin-induced morphologic changes. First, the normally discoid platelet became rounder in form, with filopodia, and the granules clustered in its center. The granules then fused with one another and with elements of the surface-connected canalicular system (SCCS) to form large vacuoles in the center of the cell and near the periphery. Neither these vacuoles nor the alpha granules appeared to fuse with the plasma membrane, but the vacuoles were connected to the extracellular space by wide necks, presumably formed by enlargement of the narrow necks connecting the SCCS to the surface of the unstimulated cell. The presence of fibrinogen, beta TG, and PF4 in corresponding large intracellular vacuoles and along the platelet plasma membrane after thrombin stimulation was demonstrated by immunocytochemical techniques in saponin-permeabilized and nonpermeabilized platelets. Immunocytochemical labeling of the three proteins on frozen thin sections of thrombin-stimulated platelets confirmed these findings and showed that all three proteins reached the plasma membrane by the same pathway. We conclude that thrombin stimulation of platelets causes at least some of the fibrinogen, beta TG, and PF4 stored in their alpha granules to be redistributed to their plasma membranes by way of surface-connected vacuoles formed by fusion of the alpha granules with elements of the SCCS.

scholarly journals Calcitonin gene-related peptide receptor antagonist human CGRP-(8-37)

1989 ◽  
Vol 256 (2) ◽  
pp. E331-E335 ◽  
Author(s):  
T. Chiba ◽  
A. Yamaguchi ◽  
T. Yamatani ◽  
A. Nakamura ◽  
T. Morishita ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Adenylate Cyclase ◽  
Calcitonin Gene Related Peptide ◽  
Human Calcitonin ◽  
Liver Plasma Membrane ◽  
Related Peptide ◽  
Calcitonin Gene ◽  
Liver Membranes ◽  
Calcitonin Receptors ◽  
Stimulation Of

From this study, we predicted that the human calcitonin gene-related peptide (hCGRP) fragment hCGRP-(8-37) would be a selective antagonist for CGRP receptors but an agonist for calcitonin (CT) receptors. In rat liver plasma membrane, where CGRP receptors predominate and CT appears to act through these receptors, hCGRP-(8-37) dose dependently displaced 125I-[Tyr0]rat CGRP binding. However, hCGRP-(8-37) had no effect on adenylate cyclase activity in liver plasma membrane. Furthermore, hCGRP-(8-37) inhibited adenylate cyclase activation induced not only by hCGRP but also by hCT. On the other hand, in LLC-PK1 cells, where calcitonin receptors are abundant and CGRP appears to act via these receptors, the bindings of 125I-[Tyr0]rat CGRP and 125I-hCT were both inhibited by hCGRP-(8-37). In contrast to liver membranes, interaction of hCGRP-(8-37) with these receptors led to stimulation of adenosine 3',5'-cyclic monophosphate (cAMP) production in LLC-PK1 cells, and moreover, this fragment did not inhibit the increased production of cAMP induced not only by hCT but also by hCGRP. Thus hCGRP-(8-37) appears to be a useful tool for determining whether the action of CGRP as well as that of CT is mediated via specific CGRP receptors or CT receptors.

scholarly journals The endosomal transcriptional regulator RNF11 integrates degradation and transport of EGFR

2016 ◽  
Vol 215 (4) ◽  
pp. 543-558 ◽  
Author(s):  
Sandra Scharaw ◽  
Murat Iskar ◽  
Alessandro Ori ◽  
Gaelle Boncompain ◽  
Vibor Laketa ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Egf Receptor ◽  
Regulatory Mechanism ◽  
Transcriptional Regulator ◽  
Transport Efficiency ◽  
Early Endosomes ◽  
Epidermal Growth ◽  
Partial Degradation ◽  
Stimulation Of

Stimulation of cells with epidermal growth factor (EGF) induces internalization and partial degradation of the EGF receptor (EGFR) by the endo-lysosomal pathway. For continuous cell functioning, EGFR plasma membrane levels are maintained by transporting newly synthesized EGFRs to the cell surface. The regulation of this process is largely unknown. In this study, we find that EGF stimulation specifically increases the transport efficiency of newly synthesized EGFRs from the endoplasmic reticulum to the plasma membrane. This coincides with an up-regulation of the inner coat protein complex II (COPII) components SEC23B, SEC24B, and SEC24D, which we show to be specifically required for EGFR transport. Up-regulation of these COPII components requires the transcriptional regulator RNF11, which localizes to early endosomes and appears additionally in the cell nucleus upon continuous EGF stimulation. Collectively, our work identifies a new regulatory mechanism that integrates the degradation and transport of EGFR in order to maintain its physiological levels at the plasma membrane.

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