scholarly journals Plasma Membrane Fluidity: An Environment Thermal Detector in Plants

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2778
Author(s):  
Dora L. Cano-Ramirez ◽  
Laura Carmona-Salazar ◽  
Francisco Morales-Cedillo ◽  
Jorge Ramírez-Salcedo ◽  
Edgar B. Cahoon ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Fluidity ◽  
Thermal Detector ◽  
Natural Habitats ◽  
Thermal Plasticity ◽  
Thermal Signal ◽  
Temperature Detection ◽  
Temperature Detector ◽  
A Cell ◽  
Response To Temperature

The lipid matrix in cell membranes is a dynamic, bidimensional array of amphipathic molecules exhibiting mesomorphism, which contributes to the membrane fluidity changes in response to temperature fluctuation. As sessile organisms, plants must rapidly and accurately respond to environmental thermal variations. However, mechanisms underlying temperature perception in plants are poorly understood. We studied the thermal plasticity of membrane fluidity using three fluorescent probes across a temperature range of −5 to 41 °C in isolated microsomal fraction (MF), vacuolar membrane (VM), and plasma membrane (PM) vesicles from Arabidopsis plants. Results showed that PM were highly fluid and exhibited more phase transitions and hysteresis, while VM and MF lacked such attributes. These findings suggest that PM is an important cell hub with the capacity to rapidly undergo fluidity modifications in response to small changes of temperatures in ranges spanning those experienced in natural habitats. PM fluidity behaves as an ideal temperature detector: it is always present, covers the whole cell, responds quickly and with sensitivity to temperature variations, functions with a cell free-energy cost, and it is physically connected with potential thermal signal transducers to elicit a cell response. It is an optimal alternative for temperature detection selected for the plant kingdom.

scholarly journals CMOS based thermal detector for processor

2020 ◽  
Vol 18 (1) ◽  
pp. 276
Author(s):  
Lee Che Yang ◽  
Warsuzarina Mat Jubadi
Keyword(s):  
Average Power ◽  
Cmos Technology ◽  
Processing Unit ◽  
Thermal Detector ◽  
Detection Range ◽  
Analog To Digital ◽  
Central Processing ◽  
Temperature Detection ◽  
Temperature Detector ◽  
Low Power Cmos

<p>This project proposed a design of low power CMOS-based thermal detector which can detect the temperature of processor such as in Central Processing Unit. By re-designing temperature detector circuit using CMOS technology, the reduction in power consumption and area size of the thermal detector can be obtained.  In this paper, the design of thermal detector consists of temperature sensing core, amplifier, and Analog to Digital Converter (ADC), respectively. The sensor was designed using 0.13 µm CMOS technology and operates by sensing the temperature of processor and produced a digital output value. The temperature detection range was setup between 0 °C to 80 °C with 10 °C resolution. The temperature detector was capable to show temperature readings in binary value. It consumed an average power of 558.2 µW and a space occupancy of 0.0118 mm².</p>

scholarly journals A cell-free assay for the insertion of a viral glycoprotein into the plasma membrane.

1986 ◽  
Vol 103 (5) ◽  
pp. 1829-1835 ◽  
Author(s):  
P G Woodman ◽  
J M Edwardson
Keyword(s):  
Influenza Virus ◽  
Plasma Membrane ◽  
Trichloroacetic Acid ◽  
Plasma Membranes ◽  
Semliki Forest Virus ◽  
Fusion Reaction ◽  
Viral Glycoprotein ◽  
Acetylneuraminic Acid ◽  
Donor And Acceptor ◽  
A Cell

A cell-free assay has been developed for the delivery of influenza virus neuraminidase to the plasma membrane. Two types of postnuclear supernatant, which acted as donor and acceptor of the enzyme, were prepared from baby hamster kidney cells. Donor preparations were obtained from cells infected with influenza virus and containing neuraminidase en route to the plasma membrane. Acceptor preparations were obtained from cells containing, bound to their plasma membranes, Semliki Forest virus with envelope glycoproteins bearing [3H]N-acetylneuraminic acid. Fusion between vesicles from these two preparations permits access of the enzyme to its substrate, which results in the release of free [3H]N-acetylneuraminic acid. This release was detected through the transfer of radioactivity from a trichloroacetic acid-insoluble to a trichloroacetic acid-soluble fraction. An ATP-dependent component of release was found, which appears to be a consequence of vesicle fusion. This component was enhanced when the donor was prepared from cells in which the enzyme had been concentrated in a compartment between the Golgi complex and the plasma membrane, which indicates that a specific exocytic fusion event has been reconstituted. The extent of fusion is greatly reduced by pre-treatment of donor and acceptor preparations with trypsin, which points to the involvement of proteins in the fusion reaction.

Time-Course of Changes in the Plasma–Membrane Lipid Bilayer and Cellular Ultrastructure Induced by Tumour Necrosis Factor-α in K 562 and Daudi Cells

1995 ◽  
Vol 23 (4) ◽  
pp. 254-263 ◽  
Author(s):  
M Marutaka ◽  
H Iwagaki ◽  
K Mizukawa ◽  
N Tanaka ◽  
K Orita
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Fluidity ◽  
Time Course ◽  
Membrane Lipid ◽  
Plasma Membrane Lipid ◽  
Membrane Lipid Bilayer ◽  
Cell Membrane Fluidity ◽  
K 562 Cells ◽  
Factor Α

The time-course of changes in the plasma-membrane lipid bilayer induced by tumour necrosis factor-α (TNF) were investigated in cultured cells using spin-label electron-spin-resonance techniques. Treatment of K 562 cells, a human chronic myelocytic leukaemia cell line, in suspension culture with TNF for up to 6 h caused an initial increase in cell-membrane fluidity, which returned to the control level after 12 h of treatment. After 24 h of treatment, the cell-membrane fluidity had decreased and this decrease was maintained after 48 h of treatment. In Daudi cells, a human malignant lymphoma cell line, TNF, did not induce any changes in cell-membrane fluidity, indicating that the effect of TNF on membrane structure is cell-specific. The early and transient change in membrane fluidity in K 562 cells is probably related to signal generation, while the later, persistent change may reflect the phenotype of TNF-treated cells, in particular, changes in the plasma membrane-cytoplasmic complex. Histochemical electron microscopic studies indicated that the membrane fluidity changes induced by TNF have an ultrastructural correlate.

The influence of dietary lipids on the composition and membrane fluidity of rat hepatocyte plasma membrane

Lipids ◽  
1997 ◽  
Vol 32 (2) ◽  
pp. 179-184 ◽  
Author(s):  
A. G. Clamp ◽  
S. Ladha ◽  
D. C. Clark ◽  
R. F. Grimble ◽  
E. K. Lund
Keyword(s):  
Plasma Membrane ◽  
Membrane Fluidity ◽  
Dietary Lipids ◽  
Rat Hepatocyte

Plasma membrane fluidity in isolated rat hepatocytes: A comparative study using DPH and TMA-DPH as fluorescent probes

1989 ◽  
Vol 4 (3) ◽  
pp. 221-227 ◽  
Author(s):  
ANTONIO BENEDETTI ◽  
GIANNA FERRETTI ◽  
GIOVANNA CURATOLA ◽  
EUGENIO BRUNELLI ◽  
ANNE MARIE JÉZÉQUEL ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Comparative Study ◽  
Membrane Fluidity ◽  
Fluorescent Probes ◽  
Rat Hepatocytes ◽  
Isolated Rat Hepatocytes ◽  
Plasma Membrane Fluidity ◽  
Isolated Rat

scholarly journals Asterosap, an Egg Jelly Peptide, Elevate Intracellular Ca2+ and Activate the Motility of Spermatozoa

2013 ◽  
Vol 19 (1) ◽  
pp. 79-88 ◽  
Author(s):  
MS Islam ◽  
T Akhter ◽  
M Matsumoto
Keyword(s):  
Plasma Membrane ◽  
Cyclic Gmp ◽  
Guanylyl Cyclase ◽  
Acrosome Reaction ◽  
Nickel Chloride ◽  
Selective Inhibitor ◽  
Ion Flux ◽  
Intracellular Ca ◽  
A Cell ◽  
Egg Jelly

Components from the outer envelopes of the egg that influence the flagellar beating and acrosome reaction of spermatozoa are regulated by ion flux across the plasma membrane. Asterosap, a sperm-activating peptide from the starfish egg jelly layer, causes a transient increase in intracellular cyclic GMP (cGMP) through the activation of the asterosap receptor, a guanylyl cyclase (GC), and causes an increase in intracellular Ca2+. Here we describe the pathway of asterosap-induced Ca2+ elevation using different Ca2+ channel antagonists. Fluo-4 AM, a cell permeable Ca2+ sensitive dye was used to determine the channel caused by the asterosap-induced Ca2+ elevation in spermatozoa. Different L-type Ca2+ channel antagonists, a non specific Ca2+ channel antagonist (nickel chloride), and a store-operated Ca2+ channel (SOC) antagonist do not show any significant response on asterosap-induced Ca2+ elevation, whereas KB-R7943, a selective inhibitor against Na+/Ca2+ exchanger (NCX) inhibited effectively. We also analyzed the flagellar movement of spermatozoa in artificial seawater (ASW) containing the asterosap at 100 nM ml?1. We found that spermatozoa swam vigorously with more symmetrical flagellar movement in asterosap than in ASW and KB-R7943 significantly inhibited the flagellar movement.DOI: http://dx.doi.org/10.3329/pa.v19i1.17358 Progress. Agric. 19(1): 79 - 88, 2008 

scholarly journals Electron donor cytochrome b5 is required for hyphal tip accumulation of sterol-rich plasma membrane domains and membrane fluidity in Aspergillus fumigatus

2020 ◽  
Author(s):  
Chi Zhang ◽  
Yiran Ren ◽  
Lu Gao ◽  
Huiyu Gu ◽  
Ling Lu
Keyword(s):  
Plasma Membrane ◽  
Aspergillus Fumigatus ◽  
Membrane Fluidity ◽  
Electron Donor ◽  
Cytochrome B5 ◽  
Normal Growth ◽  
Ergosterol Biosynthesis ◽  
Membrane Domains ◽  
Growth Defects ◽  
C Terminus

The electron donor cytochrome b5 (CybE/Cyb5) fuels the activity of the ergosterol biosynthesis-related P450 enzymes/P450s by providing electrons to P450s to promote ergosterol biosynthesis. Previous studies reported that lack of Aspergillus fumigatus (A. fumigatus) CybE reduces the proportion of ergosterol in total sterols and induces severe growth defects. However, the molecular characteristics of CybE and the underlying mechanism for CybE maintaining A. fumigatus growth remain poorly understood. Here, we found that CybE locates at the endoplasmic reticulum by its C-terminus with two transmembrane regions. Therefore, lack of the C-terminus of CybE is able to phenocopy a cybE deletion. Notably, cybE deletion reduced the accumulation of the sterol-rich plasma membrane domains (SRDs, the assembly platform of polarity factors/cell end markers and growth machinery) in hyphal tips and decreased membrane fluidity, which correspond to tardiness of hyphal extension and hypersensitivity to low temperature in cybE deletion mutant. Additionally, overexpressing another electron donor-heme-independent P450 reductase (CPR) significantly rescued growth defects and recovered SRD accumulation in deletion of cybE almost to the wild-type level, suggesting CybE maintaining the growth and deposition of SRDs in hyphal tips attributes to its nature as an electron donor. Protein pull-down assays revealed that CybE probably participates in metabolism and transfer of lipids, construction of cytoskeleton and mitochondria-associated energy metabolism to maintain the SRD accumulation in hyphal tips, membrane fluidity and hyphal extension. Findings in this study give a hint that inhibition of CybE may be an effective strategy for resisting the infection of the human pathogen A. fumigatus. Importance Investigating the knowledge of the growth regulation in the human opportunistic pathogen A. fumigatus is conducive to design new antifungal approach. The electron donor cytochrome b5 (CybE) plays a crucial role in maintaining the normal growth of A. fumigatus, however, the potential mechanism remains elusive. Herein, we characterized the molecular features of CybE and found the C-terminus with two transmembrane domains are required for its ER localization and functions. In addition, we demonstrated that CprA, an electron donor-heme-independent P450 reductase, provides a reciprocal function for the missing cytochrome b5 protein-CybE in A. fumigatus. CybE maintains the normal growth probably via supporting two crucial physiological processes, the SRD accumulation in hyphal tips and membrane fluidity. Therefore, our finding reveals the mechanisms underlying the regulatory effect of CybE on A. fumigatus growth and indicates that inhibition of CybE might be an effective approach for alleviating A. fumigatus infection.

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