scholarly journals A METHOD FOR THE ISOLATION OF PLASMA MEMBRANE OF ANIMAL CELLS

1971 ◽  
Vol 48 (3) ◽  
pp. 703-706 ◽  
Author(s):  
Jochen W. Heine ◽  
Carl A. Schnaitman
Keyword(s):  
Plasma Membrane ◽  
Animal Cells

Localization of Adenosine Triphosphatase Activity in the Phleom of Nicotiana Tabacum

1972 ◽  
Vol 30 ◽  
pp. 230-231
Author(s):  
James Cronshaw ◽  
Jamison E. Gilder
Keyword(s):  
Plasma Membrane ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Higher Plants ◽  
High Surface ◽  
Root Tip ◽  
Animal Cells ◽  
Physiological Processes ◽  
Tip Cells ◽  
Atpase Localization

Adenosine triphosphatase (ATPase) activity has been shown to be associated with numerous physiological processes in both plants and animal cells. Biochemical studies have shown that in higher plants ATPase activity is high in cell wall preparations and is associated with the plasma membrane, nuclei, mitochondria, chloroplasts and lysosomes. However, there have been only a few ATPase localization studies of higher plants at the electron microscope level. Poux (1967) demonstrated ATPase activity associated with most cellular organelles in the protoderm cells of Cucumis roots. Hall (1971) has demonstrated ATPase activity in root tip cells of Zea mays. There was high surface activity largely associated with the plasma membrane and plasmodesmata. ATPase activity was also demonstrated in mitochondria, dictyosomes, endoplasmic reticulum and plastids.

scholarly journals Diacylglycerol activates the influx of extracellular cations in T-lymphocytes independently of intracellular calcium-store depletion and possibly involving endogenous TRP6 gene products

2002 ◽  
Vol 364 (1) ◽  
pp. 245-254 ◽  
Author(s):  
Alessandra GAMBERUCCI ◽  
Emanuele GIURISATO ◽  
Paola PIZZO ◽  
Maristella TASSI ◽  
Roberta GIUNTI ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
T Lymphocytes ◽  
Peripheral Blood ◽  
Transient Receptor Potential ◽  
Human Peripheral Blood ◽  
Receptor Potential ◽  
Animal Cells ◽  
Bivalent Cation ◽  
Intracellular Calcium Store ◽  
Transient Receptor

In Jurkat and human peripheral blood T-lymphocytes, 1-oleoyl-2-acetyl-sn-glycerol (OAG), a membrane-permeant analogue of diacylglycerol, activated the influx of Ca2+, Ba2+ and Sr2+. OAG also caused plasma-membrane depolarization in Ca2+-free media that was recovered by the addition of bivalent cation, indicating the activation of Na+ influx. OAG-induced cation influx was (i) mimicked by the natural dacylglycerol 1-stearoyl-2-arachidonyl-sn-glycerol, (ii) not blocked by inhibiting protein kinase C or in the absence of phopholipase C activity and (iii) blocked by La3+ and Gd3+. Differently from OAG, both thapsigargin and phytohaemagglutinin activated a potent influx of Ca2+, but little influx of Ba2+ and Sr2+. Moreover, the influx of Ca2+ activated by thapsigargin and that activated by OAG were additive. Furthermore, several drugs (i.e. econazole, SKF96365, carbonyl cyanide p-trifluoromethoxyphenylhydrazone, 2-aminoethoxy diphenylborate and calyculin-A), while inhibiting the influx of Ca2+ induced by both thapsigargin and phytohaemagglutinin, did not affect OAG-stimulated cation influx. Transient receptor potential (TRP) 3 and TRP6 proteins have been shown previously to be activated by diacylglycerol when expressed heterologously in animal cells [Hofmann, Obukhov, Schaefer, Harteneck, Gudermann and Schultz (1999) Nature (London) 397, 259–263]. In both Jurkat and peripheral blood T-lymphocytes, mRNA encoding TRP proteins 1, 3, 4 and 6 was detected by reverse transcriptase PCR, and the TRP6 protein was detected by Western blotting in a purified plasma-membrane fraction. We conclude that T-cells express a diacylglycerol-activated cation channel, unrelated to the channel involved in capacitative Ca2+ entry, and associated with the expression of TRP6 protein.

The Cell's Biological Rods and Ropes

MRS Bulletin ◽  
1999 ◽  
Vol 24 (10) ◽  
pp. 27-31 ◽  
Author(s):  
David Boal
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Chemical Composition ◽  
Intermediate Filaments ◽  
Plant Cells ◽  
Cell Type ◽  
Animal Cells ◽  
Limited Variation ◽  
A Cell ◽  
Mechanical Elements

Despite a variety of shapes and sizes, the generic mechanical structure of cells is remarkably similar from one cell type to the next. All cells are bounded by a plasma membrane, a fluid sheet that controls the passage of materials into and out of the cell. Plant cells and bacteria reinforce this membrane with a cell wall, permitting the cell to operate at an elevated osmotic pressure. Simple cells, such as the bacterium shown in Figure 1a, possess a fairly homogeneous interior containing the cell's genetic blueprint and protein workhorses, but no mechanical elements. In contrast, as can be seen in Figure 1b, plant and animal cells contain internal compartments and a filamentous cytoskeleton—a network of biological ropes, cables, and poles that helps maintain the cell's shape and organize its contents.Four principal types of filaments are found in the cytoskeleton: spectrin, actin, microtubules, and a family of intermediate filaments. Not all filaments are present in all cells. The chemical composition of the filaments shows only limited variation from one cell to another, even in organisms as diverse as humans and yeasts. Membranes have a more variable composition, consisting of a bi-layer of dual-chain lipid molecules in which are embedded various proteins and frequently a moderate concentration of cholesterol. The similarity of the cell's mechanical elements in chemical composition and physical characteristics encourages us to search for universal strategies that have developed in nature for the engineering specifications of the cell. In this article, we concentrate on the cytoskeleton and its filaments.

scholarly journals Structure and Distribution of Organelles and Cellular Location of Calcium Transporters in Neurospora crassa

2009 ◽  
Vol 8 (12) ◽  
pp. 1845-1855 ◽  
Author(s):  
Barry J. Bowman ◽  
Marija Draskovic ◽  
Michael Freitag ◽  
Emma Jean Bowman
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Neurospora Crassa ◽  
Fluorescent Protein ◽  
Protein A ◽  
Vacuolar Membrane ◽  
Red Fluorescent Protein ◽  
Animal Cells ◽  
Marker Proteins ◽  
Hyphal Tip

ABSTRACT We wanted to examine the cellular locations of four Neurospora crassa proteins that transport calcium. However, the structure and distribution of organelles in live hyphae of N. crassa have not been comprehensively described. Therefore, we made recombinant genes that generate translational fusions of putative organellar marker proteins with green or red fluorescent protein. We observed putative endoplasmic reticulum proteins, encoded by grp-78 and dpm, in the nuclear envelope and associated membranes. Proteins of the vacuolar membrane, encoded by vam-3 and vma-1, were in an interconnected network of small tubules and vesicles near the hyphal tip, while in more distal regions they were in large and small spherical vacuoles. Mitochondria, visualized with tagged ARG-4, were abundant in all regions of the hyphae. Similarly, we tagged the four N. crassa proteins that transport calcium with green or red fluorescent protein to examine their cellular locations. NCA-1 protein, a homolog of the SERCA-type Ca2+-ATPase of animal cells, colocalized with the endoplasmic reticulum markers. The NCA-2 and NCA-3 proteins are homologs of Ca2+-ATPases in the vacuolar membrane in yeast or in the plasma membrane in animal cells. They colocalized with markers in the vacuolar membrane, and they also occurred in the plasma membrane in regions of the hyphae more than 1 mm from the tip. The cax gene encodes a Ca2+/H+ exchange protein found in vacuoles. As expected, the CAX protein localized to the vacuolar compartment. We observed, approximately 50 to 100 μm from the tip, a few spherical organelles that had high amounts of tagged CAX protein and tagged subunits of the vacuolar ATPase (VMA-1 and VMA-5). We suggest that this organelle, not described previously in N. crassa, may have a role in sequestering calcium.

Transport of lipids to the plasma membrane in animal cells

1993 ◽  
Vol 32 (2) ◽  
pp. 195-219 ◽  
Author(s):  
David Allan ◽  
Karl-Josef Kallen
Keyword(s):  
Plasma Membrane ◽  
Animal Cells

Evolutionary origins of eukaryotic sodium/proton exchangers

2005 ◽  
Vol 288 (2) ◽  
pp. C223-C239 ◽  
Author(s):  
Christopher L. Brett ◽  
Mark Donowitz ◽  
Rajini Rao
Keyword(s):  
Plasma Membrane ◽  
Drug Sensitivity ◽  
Phylogenetic Analyses ◽  
Subcellular Location ◽  
Monovalent Cation ◽  
Model Organisms ◽  
Sequence Length ◽  
Animal Cells ◽  
Cation Selectivity ◽  
Evolutionary Origins

More than 200 genes annotated as Na+/H+hydrogen exchangers (NHEs) currently reside in bioinformation databases such as GenBank and Pfam. We performed detailed phylogenetic analyses of these NHEs in an effort to better understand their specific functions and physiological roles. This analysis initially required examining the entire monovalent cation proton antiporter (CPA) superfamily that includes the CPA1, CPA2, and NaT-DC families of transporters, each of which has a unique set of bacterial ancestors. We have concluded that there are nine human NHE (or SLC9A) paralogs as well as two previously unknown human CPA2 genes, which we have named HsNHA1 and HsNHA2. The eukaryotic NHE family is composed of five phylogenetically distinct clades that differ in subcellular location, drug sensitivity, cation selectivity, and sequence length. The major subgroups are plasma membrane (recycling and resident) and intracellular (endosomal/TGN, NHE8-like, and plant vacuolar). HsNHE1, the first cloned eukaryotic NHE gene, belongs to the resident plasma membrane clade. The latter is the most recent to emerge, being found exclusively in vertebrates. In contrast, the intracellular clades are ubiquitously distributed and are likely precursors to the plasma membrane NHE. Yeast endosomal ScNHX1 was the first intracellular NHE to be described and is closely related to HsNHE6, HsNHE7, and HsNHE9 in humans. Our results link the appearance of NHE on the plasma membrane of animal cells to the use of the Na+/K+-ATPase to generate the membrane potential. These novel observations have allowed us to use comparative biology to predict physiological roles for the nine human NHE paralogs and to propose appropriate model organisms in which to study the unique properties of each NHE subclass.

scholarly journals Essential function of Drosophila Sec6 in apical exocytosis of epithelial photoreceptor cells

2005 ◽  
Vol 169 (4) ◽  
pp. 635-646 ◽  
Author(s):  
Slobodan Beronja ◽  
Patrick Laprise ◽  
Ophelia Papoulas ◽  
Milena Pellikka ◽  
John Sisson ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Protein Transport ◽  
Basolateral Membrane ◽  
Photoreceptor Cells ◽  
Secretory Vesicles ◽  
Membrane Domains ◽  
Animal Cells ◽  
Light Sensing ◽  
Membrane Growth ◽  
Essential Function

Polarized exocytosis plays a major role in development and cell differentiation but the mechanisms that target exocytosis to specific membrane domains in animal cells are still poorly understood. We characterized Drosophila Sec6, a component of the exocyst complex that is believed to tether secretory vesicles to specific plasma membrane sites. sec6 mutations cause cell lethality and disrupt plasma membrane growth. In developing photoreceptor cells (PRCs), Sec6 but not Sec5 or Sec8 shows accumulation at adherens junctions. In late PRCs, Sec6, Sec5, and Sec8 colocalize at the rhabdomere, the light sensing subdomain of the apical membrane. PRCs with reduced Sec6 function accumulate secretory vesicles and fail to transport proteins to the rhabdomere, but show normal localization of proteins to the apical stalk membrane and the basolateral membrane. Furthermore, we show that Rab11 forms a complex with Sec5 and that Sec5 interacts with Sec6 suggesting that the exocyst is a Rab11 effector that facilitates protein transport to the apical rhabdomere in Drosophila PRCs.

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