Functional Aspects of Plasma Membrane Studies: Growth Regulation by Ionic Fluxes

1981 ◽  
pp. 27-36
Author(s):  
W. H. Moolenaar
Keyword(s):  
Plasma Membrane ◽  
Growth Regulation ◽  
Ionic Fluxes ◽  
Functional Aspects

scholarly journals Distribution and Activity of the Plasma Membrane H+-ATPase in Mimosa pudica L. in Relation to Ionic Fluxes and Leaf Movements

1997 ◽  
Vol 113 (3) ◽  
pp. 747-754 ◽  
Author(s):  
P. Fleurat-Lessard ◽  
S. Bouche-Pillon ◽  
C. Leloup ◽  
J. L. Bonnemain
Keyword(s):  
Plasma Membrane ◽  
Mimosa Pudica ◽  
Ionic Fluxes ◽  
Leaf Movements

Ionic Channels in Sea Urchin Sperm Physiology

Physiology ◽  
1988 ◽  
Vol 3 (5) ◽  
pp. 181-185
Author(s):  
A Darszon ◽  
A Guerrero ◽  
A Lievano ◽  
M Gonzalez-Martinez ◽  
E Morales
Keyword(s):  
Plasma Membrane ◽  
Sea Urchin ◽  
Acrosome Reaction ◽  
Ionic Channels ◽  
Good Evidence ◽  
Ionic Fluxes ◽  
Sea Urchin Sperm

In sea urchin sperm, ionic fluxes modulate the activation of respiration and motility and the acrosome reaction, a prerequisite for egg fertilization. Ionic channels are present in the plasma membrane of these cells, and there is good evidence indicating that they are deeply involved in these processes.

scholarly journals Antagonistic cell surface and intracellular auxin signalling regulate plasma membrane H -fluxes for root growth

2021 ◽  
Author(s):  
Lanxin Li ◽  
Inge Verstraeten ◽  
Mark Roosjen ◽  
Koji Takahashi ◽  
Lesia Rodriguez ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Root Growth ◽  
Growth Regulation ◽  
Growth Modulation ◽  
Auxin Signalling ◽  
Direct Growth ◽  
Simultaneous Activation ◽  
Growth Adaptation ◽  
Apoplast Acidification

Abstract Growth regulation tailors plant development to its environment. A showcase is growth adaptation to gravity, where shoots bend up and roots down. This paradox is based on different responses to the phytohormone auxin, which promotes cell expansion in shoots, while inhibiting it in roots via a yet unknown cellular mechanism. Here, by combining microfluidics, live imaging, genetic engineering and phospho-proteomics in Arabidopsis thaliana, we reveal how auxin inhibits root growth. We show that auxin activates two distinct, antagonistically acting signalling pathways that converge on the rapid regulation of the apoplastic pH, which is the direct growth-determining mechanism. Cell surface-based TRANSMEMBRANE KINASE 1 (TMK1) interacts with and mediates phosphorylation and activation of plasma membrane H+-ATPases for apoplast acidification, while intracellular TIR1/AFB-mediated signalling triggers net cellular H+-influx, causing apoplast alkalinisation. The simultaneous activation of these two counteracting mechanisms poises the root for a rapid, fine-tuned growth modulation to subtle changes in the environment.

scholarly journals NINJ1 mediates plasma membrane rupture during lytic cell death

2020 ◽  
Author(s):  
Nobuhiko Kayagaki ◽  
Opher Kornfeld ◽  
Bettina Lee ◽  
Irma Stowe ◽  
Karen O'Rourke ◽  
...  
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Apoptotic Cell ◽  
High Mobility ◽  
Surface Protein ◽  
Underlying Mechanism ◽  
Cell Swelling ◽  
Membrane Pore ◽  
Membrane Rupture ◽  
Ionic Fluxes

Abstract Plasma membrane rupture (PMR) is the final cataclysmic event in lytic cell death. PMR releases intracellular molecules termed damage-associated molecular patterns (DAMPs) that propagate the inflammatory response. The underlying mechanism for PMR, however, is unknown. Here we show that the ill-characterized nerve injury-induced protein 1 (NINJ1) — a cell surface protein with two transmembrane regions — plays an essential role in the induction of PMR. A forward-genetic screen of randomly mutagenized mice linked NINJ1 to PMR. Ninj1–/– macrophages exhibited impaired PMR in response to diverse inducers of pyroptotic, necrotic and apoptotic cell death, and failed to release numerous intracellular proteins including High Mobility Group Box 1 (HMGB1, a known DAMP) and Lactate Dehydrogenase (LDH, a standard measure of PMR). Ninj1–/– macrophages died, but with a distinctive and persistent ballooned morphology, attributable to defective disintegration of bubble-like herniations. Ninj1–/– mice were more susceptible than wild-type mice to Citrobacter rodentium, suggesting a role for PMR in anti-bacterial host defense. Mechanistically, NINJ1 utilized an evolutionarily conserved extracellular α-helical domain for oligomerization and subsequent PMR. The discovery of NINJ1 as a mediator of PMR overturns the long-held dogma that cell death-related PMR is a passive event. Pyroptosis is a potent inflammatory mode of lytic cell death triggered by diverse infectious and sterile insults1-3. It is driven by the pore-forming fragment of gasdermin D (GSDMD)4-7 and releases two exemplar proteins: interleukin-1β (IL-1β), a pro-inflammatory cytokine, and LDH, a standard marker of PMR and lytic cell death. An early landmark study8 predicted two sequential steps for pyroptosis: (1) initial formation of a small plasma membrane pore causing IL-1β release and non-selective ionic fluxes, and (2) subsequent PMR attributable to oncotic cell swelling. PMR releases LDH (140 kDa) and large DAMPs. While the predicted size of gasdermin pores (~18 nm inner diameter9) is large enough to release IL-1β (17 kDa, ~4.5 nm diameter), the underlying mechanism for subsequent PMR has been considered a passive osmotic lysis event.

VAP-33 localizes to both an intracellular vesicle population and with occludin at the tight junction

1999 ◽  
Vol 112 (21) ◽  
pp. 3723-3732 ◽  
Author(s):  
L.A. Lapierre ◽  
P.L. Tuma ◽  
J. Navarre ◽  
J.R. Goldenring ◽  
J.M. Anderson
Keyword(s):  
Plasma Membrane ◽  
Tight Junction ◽  
Tight Junctions ◽  
Growth Regulation ◽  
Mdck Cells ◽  
Transmembrane Protein ◽  
Subcellular Fractionation ◽  
Tissue Culture Cell ◽  
Cellular Functions ◽  
Vesicle Docking

Tight junctions create a regulated intercellular seal between epithelial and endothelial cells and also establish polarity between plasma membrane domains within the cell. Tight junctions have also been implicated in many other cellular functions, including cell signaling and growth regulation, but they have yet to be directly implicated in vesicle movement. Occludin is a transmembrane protein located at tight junctions and is known to interact with other tight junction proteins, including ZO-1. To investigate occludin's role in other cellular functions we performed a yeast two-hybrid screen using the cytoplasmic C terminus of occludin and a human liver cDNA library. From this screen we identified VAP-33 which was initially cloned from Aplysia by its ability to interact with VAMP/synaptobrevin and thus was implicated in vesicle docking/fusion. Extraction characteristics indicated that VAP-33 was an integral membrane protein. Antibodies to the human VAP-33 co-localized with occludin at the tight junction in many tissues and tissue culture cell lines. Subcellular fractionation of liver demonstrated that 83% of VAP-33 co-isolated with occludin and DPPIV in a plasma membrane fraction and 14% fractionated in a vesicular pool. Thus, both immunofluorescence and fractionation data suggest that VAP-33 is present in two distinct pools in the cells. In further support of this conclusion, a GFP-VAP-33 chimera also distributed to two sites within MDCK cells and interestingly shifted occludin's localization basally. Since VAP-33 has previously been implicated in vesicle docking/fusion, our results suggest that tight junctions may participate in vesicle targeting at the plasma membrane or alternatively VAP-33 may regulate the localization of occludin.

scholarly journals Antagonistic cell surface and intracellular auxin signalling regulate plasma membrane H+-fluxes for root growth

2021 ◽  
Author(s):  
Lanxin Li ◽  
Inge Verstraeten ◽  
Mark Roosjen ◽  
Koji Takahashi ◽  
Lesia Rodriguez ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Root Growth ◽  
Growth Regulation ◽  
Signalling Pathways ◽  
Soil Environment ◽  
Growth Modulation ◽  
Auxin Signalling ◽  
Simultaneous Activation ◽  
Apoplast Acidification

Abstract Growth regulation tailors plant development to its environment. A showcase is response to gravity, where shoots bend up and roots down1. This paradox is based on opposite effects of the phytohormone auxin, which promotes cell expansion in shoots, while inhibiting it in roots via a yet unknown cellular mechanism2. Here, by combining microfluidics, live imaging, genetic engineering and phospho-proteomics in Arabidopsis thaliana, we advance our understanding how auxin inhibits root growth. We show that auxin activates two distinct, antagonistically acting signalling pathways that converge on the rapid regulation of the apoplastic pH, a causative growth determinant. Cell surface-based TRANSMEMBRANE KINASE1 (TMK1) interacts with and mediates phosphorylation and activation of plasma membrane H+-ATPases for apoplast acidification, while intracellular canonical auxin signalling promotes net cellular H+-influx, causing apoplast alkalinisation. The simultaneous activation of these two counteracting mechanisms poises the root for a rapid, fine-tuned growth modulation while navigating complex soil environment.

Morphological and functional aspects of STIM1-dependent assembly and disassembly of store-operated calcium entry complexes

2012 ◽  
Vol 40 (1) ◽  
pp. 112-118 ◽  
Author(s):  
Wei-Wei Shen ◽  
Nicolas Demaurex
Keyword(s):  
Plasma Membrane ◽  
Conformational Changes ◽  
Cell Signalling ◽  
Ultrastructural Level ◽  
Central Component ◽  
Cell Periphery ◽  
Functional Aspects ◽  
Drive Gene Expression ◽  
Store Operated Calcium Entry ◽  
Drive Gene

The SOCE (store-operated Ca2+ entry) pathway is a central component of cell signalling that links the Ca2+-filling state of the ER (endoplasmic reticulum) to the activation of Ca2+-permeable channels at the PM (plasma membrane). SOCE channels maintain a high free Ca2+ concentration within the ER lumen required for the proper processing and folding of proteins, and fuel the long-term cellular Ca2+ signals that drive gene expression in immune cells. SOCE is initiated by the oligomerization on the membrane of the ER of STIMs (stromal interaction molecules) whose luminal EF-hand domain switches from globular to an extended conformation as soon as the free Ca2+ concentration within the ER lumen ([Ca2+]ER) decreases below basal levels of ~500 μM. The conformational changes induced by the unbinding of Ca2+ from the STIM1 luminal domain promote the formation of higher-order STIM1 oligomers that move towards the PM and exposes activating domains in STIM1 cytosolic tail that bind to Ca2+ channels of the Orai family at the PM and induce their activation. Both SOCE and STIM1 oligomerization are reversible events, but whether restoring normal [Ca2+]ER levels is sufficient to initiate the deoligomerization of STIM1 and to control the termination of SOCE is not known. The translocation of STIM1 towards the PM involves the formation of specialized compartments derived from the ER that we have characterized at the ultrastructural level and termed the pre-cortical ER, the cortical ER and the thin cortical ER. Pre-cortical ER structures are thin ER tubules enriched in STIM1 extending along microtubules and located deep inside cells. The cortical ER is located in the cell periphery in very close proximity (8–11 nm) to the plasma membrane. The thin cortical ER consists of thinner sections of the cortical ER enriched in STIM1 and devoid of chaperones that appear to be specialized ER compartments dedicated to Ca2+ signalling.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

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