Catecholamine-induced changes in plasma membrane biochemistry and function

1987 ◽  
Vol 7 (2) ◽  
pp. 183-226 ◽  
Author(s):  
Hartmut Porzig
1980 ◽  
Vol 85 (2) ◽  
pp. 213-227 ◽  
Author(s):  
J Beisson ◽  
J Cohen ◽  
M Lefort-Tran ◽  
M Pouphile ◽  
M Rossignol

Previous studies on exocytosis in Paramecium using mutants affecting trichocyst extrusion permitted us to analyze the assembly and function of three intramembrane particle arrays ("ring" and "rosette" in the plasma membrane, "annulus" in the trichocyst membrane) involved in the interaction between these two membranes. Using a conditional mutation, nd9, which blocks rosette assembly and prevents exocytosis at the nonpermissive temperature, we have analyzed the effect of temperature on the secretory capacity of nd9 cells. By combining several techniques (physiological studies, microinjections, inhibition of fatty acid synthesis, and freeze-fracture analysis) we demonstrate (a) that the product of the mutated allele nd9 is not thermolabile but that its activity is dependent upon temperature-induced changes in the membrane lipid composition and (b) that the product of the nd9 locus is a diffusible cytoplasmic component whose interaction with both plasma membrane and trichocyst membrane is required for rosette assembly and exocytosis. The data provide physiological evidence for the existence of a molecular complex(es) linking the two membranes and involved in the control of membrane fusion; we discuss the possible nature and function of these links.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 823E-823
Author(s):  
Gene E. Lester ◽  
Bruce D. Whitaker

Postharvest gamma-irradiation of melons at low dosage has been reported to extend shelf life. This study assessed how irradiation alters the structure and function of plasma membrane (PM) from hypodermal-mesocarp tissue. Administration of gamma rays (1 kGy at 0.017 kGy/min) to mature melon (Cucumis melo L.) fruit caused a 14% drop in H+-ATPase activity within 4 h. Total protein content did not differ in PM from non-irradiated (NIR) vs. irradiated (IR) fruits. Following storage (7 days at 7C then 3 days at 21C), H+-ATPase activity was ≈10% to 20% lower in PM from both groups of fruit, with no difference between the two. Total PM protein had declined by 34% and 49% in IR and NIR fruits, respectively. After irradiation, the phospholipid to protein ratio (PL:protein) was substantially higher in PM from IR fruit (0.67 vs. 0.58 in NIR). With storage, PL:protein dropped to 0.52 in NIR fruit PM, but changed little (0.65) in IR fruit PM. These results may indicate that irradiation stimulates PL synthesis or inhibits PL catabolism. Further analyses of PM lipid content and composition are underway.


1984 ◽  
Vol 99 (1) ◽  
pp. 95s-103s ◽  
Author(s):  
P Mangeat ◽  
K Burridge

In this review we discuss some of the proteins for which a role in linking actin to the fibroblast plasma membrane has been suggested. We focus on the family of proteins related to erythrocyte spectrin, proteins that have generally been viewed as having an organization and a function in actin-membrane attachment similar to those of erythrocyte spectrin. Experiments in which we precipitated the nonerythrocyte spectrin within living fibroblasts have led us to question this supposed similarity of organization and function of the nonerythrocyte and erythrocyte spectrins. Intracellular precipitation of fibroblast spectrin does not affect the integrity of the major actin-containing structures, the stress fiber microfilament bundles. Unexpectedly, however, we found that the precipitation of spectrin results in a condensation and altered distribution of the vimentin class of intermediate filaments in most cells examined. Although fibroblast spectrin may have a role in the attachment of some of the cortical, submembranous actin, it is surprising how little the intracellular immunoprecipitation of the spectrin affects the cells. Several proteins have been found concentrated at the ends of stress fibers, where the actin filaments terminate at focal contacts. Two of these proteins, alpha-actinin and fimbrin, have properties that suggest that they are not involved in the attachment of the ends of the bundles to the membrane but are more probably involved in the organization and cross-linking of the filaments within the bundles. On the other hand, vinculin and talin are two proteins that interact with each other and may form part of a chain of attachments between the ends of the microfilament bundles and the focal contact membrane. Their role in this attachment, however, has not been established and further work is needed to examine their interaction with actin and to identify any other components with which they may interact, particularly in the plasma membrane.


2021 ◽  
Vol 7 (7) ◽  
pp. 514
Author(s):  
Mariangela Dionysopoulou ◽  
George Diallinas

Recent biochemical and biophysical evidence have established that membrane lipids, namely phospholipids, sphingolipids and sterols, are critical for the function of eukaryotic plasma membrane transporters. Here, we study the effect of selected membrane lipid biosynthesis mutations and of the ergosterol-related antifungal itraconazole on the subcellular localization, stability and transport kinetics of two well-studied purine transporters, UapA and AzgA, in Aspergillus nidulans. We show that genetic reduction in biosynthesis of ergosterol, sphingolipids or phosphoinositides arrest A. nidulans growth after germling formation, but solely blocks in early steps of ergosterol (Erg11) or sphingolipid (BasA) synthesis have a negative effect on plasma membrane (PM) localization and stability of transporters before growth arrest. Surprisingly, the fraction of UapA or AzgA that reaches the PM in lipid biosynthesis mutants is shown to conserve normal apparent transport kinetics. We further show that turnover of UapA, which is the transporter mostly sensitive to membrane lipid content modification, occurs during its trafficking and by enhanced endocytosis, and is partly dependent on autophagy and Hect-type HulARsp5 ubiquitination. Our results point out that the role of specific membrane lipids on transporter biogenesis and function in vivo is complex, combinatorial and transporter-dependent.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Catarina Dias ◽  
Jesper Nylandsted

AbstractMaintenance of plasma membrane integrity is essential for normal cell viability and function. Thus, robust membrane repair mechanisms have evolved to counteract the eminent threat of a torn plasma membrane. Different repair mechanisms and the bio-physical parameters required for efficient repair are now emerging from different research groups. However, less is known about when these mechanisms come into play. This review focuses on the existence of membrane disruptions and repair mechanisms in both physiological and pathological conditions, and across multiple cell types, albeit to different degrees. Fundamentally, irrespective of the source of membrane disruption, aberrant calcium influx is the common stimulus that activates the membrane repair response. Inadequate repair responses can tip the balance between physiology and pathology, highlighting the significance of plasma membrane integrity. For example, an over-activated repair response can promote cancer invasion, while the inability to efficiently repair membrane can drive neurodegeneration and muscular dystrophies. The interdisciplinary view explored here emphasises the widespread potential of targeting plasma membrane repair mechanisms for therapeutic purposes.


2008 ◽  
Vol 6 (32) ◽  
pp. 293-306 ◽  
Author(s):  
A Valentín ◽  
L Cardamone ◽  
S Baek ◽  
J.D Humphrey

Arteries exhibit a remarkable ability to adapt to sustained alterations in biomechanical loading, probably via mechanisms that are similarly involved in many arterial pathologies and responses to treatment. Of particular note, diverse data suggest that cell and matrix turnover within vasoaltered states enables arteries to adapt to sustained changes in blood flow and pressure. The goal herein is to show explicitly how altered smooth muscle contractility and matrix growth and remodelling work together to adapt the geometry, structure, stiffness and function of a representative basilar artery. Towards this end, we employ a continuum theory of constrained mixtures to model evolving changes in the wall, which depend on both wall shear stress-induced changes in vasoactive molecules (which alter smooth muscle proliferation and synthesis of matrix) and intramural stress-induced changes in growth factors (which alter cell and matrix turnover). Simulations show, for example, that such considerations help explain the different rates of experimentally observed adaptations to increased versus decreased flows as well as differences in rates of change in response to increased flows or pressures.


Endocrinology ◽  
2012 ◽  
Vol 153 (12) ◽  
pp. 6126-6135 ◽  
Author(s):  
L. S. Loubière ◽  
E. Vasilopoulou ◽  
J. D. Glazier ◽  
P. M. Taylor ◽  
J. A. Franklyn ◽  
...  

Author(s):  
Sherin Saheera ◽  
Vivek P Jani ◽  
Kenneth W Witwer ◽  
Shelby Kutty

Extracellular vesicles (EVs) are nanosized lipid bilayer-delimited particles released from cells that mediate intercellular communications and play a pivotal role in various physiological and pathological processes. Subtypes of EVs may include plasma-membrane ectosomes or microvesicles and endosomal-origin exosomes, although functional distinctions remain unclear. EVs carry cargo proteins, nucleic acids (RNA and DNA), lipids, and metabolites. By presenting or transferring this cargo to recipient cells, EVs can trigger cellular responses. Here, we summarize what is known about EV biogenesis, composition, and function, with an emphasis on the role of EVs in cardiovascular system. Additionally, we provide an update on the function of EVs in cardiovascular pathophysiology, further highlighting their potential for diagnostic and therapeutic applications.


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