scholarly journals Active Transport of Membrane Components by Self-Organization of the Min Proteins

2018 ◽  
Author(s):  
YL Shih ◽  
LT Huang ◽  
YM Tu ◽  
BF Lee ◽  
YC Bau ◽  
...  
Keyword(s):  
Biological Membrane ◽  
Physical Principle ◽  
Cell Polarization ◽  
Heterogeneous Distribution ◽  
Peristaltic Pumping ◽  
Wave Patterns ◽  
Min Proteins ◽  
Distribution Of Components ◽  
Membrane Components ◽  
Steric Property

ABSTRACTHeterogeneous distribution of components in the biological membrane is critical in the process of cell polarization. However, little is known about the mechanisms that can generate and maintain the heterogeneous distribution of the membrane components. Here we report that the propagating wave patterns of the bacterial Min proteins can impose corresponding steric pressure on the membrane to establish a directional accumulation of the membrane components, resulting in segregation of the components in the membrane. The diffusivity, influenced by the membrane anchor of the component, and the repulsed ability, influenced by the steric property of the soluble region of the component and molecular crowding, determine the differential spatial distribution of the component in the membrane. Thus, transportation of the membrane components by the Min proteins follows a simple physical principle, which resembles a linear peristaltic pumping process, to selectively segregate and maintain heterogeneous distribution of materials in the membrane.

scholarly journals Active Transport of Membrane Components by Self-Organization of the Min Proteins

2019 ◽  
Vol 116 (8) ◽  
pp. 1469-1482 ◽  
Author(s):  
Yu-Ling Shih ◽  
Ling-Ting Huang ◽  
Yu-Ming Tu ◽  
Bo-Fan Lee ◽  
Yu-Chiuan Bau ◽  
...  
Keyword(s):  
Active Transport ◽  
Self Organization ◽  
Min Proteins ◽  
Membrane Components

Orientation and mobility of molecules in membranes studied by polarized light spectroscopy

1980 ◽  
Vol 13 (1) ◽  
pp. 63-118 ◽  
Author(s):  
Lennart B.-Å. Johansson ◽  
Göran Lindblom
Keyword(s):  
Molecular Orientation ◽  
Biological Membrane ◽  
Polarized Light ◽  
Spatial Arrangement ◽  
Chemical Processes ◽  
Orientation And Mobility ◽  
Mobility Of Molecules ◽  
Membrane Components ◽  
The Guardian ◽  
Functional Mechanisms

Biological membranes are composed of mainly lipids and proteins. The physical properties of the lipids, forming a bilayer structure, are of crucial importance for the living cell, since the plasma membrane is the guardian barrier towards the environment. Thus, the functioning cell needs a highly stable lipid bilayer, which depends on molecular packing and orientation properties of the various membrane components (Wieslander et al. 1980). The spatial arrangement of the membrane proteins incorporated in the lipid matrix plays an essential role for the different chemical processes occurring at or within the membrane. Information about molecular orientation and mobility is therefore necessary for unravelling the functional mechanisms of a biological membrane.

Lateral mobility of biological membrane components

1991 ◽  
Author(s):  
Dusan Chorvat ◽  
Peter Shvec ◽  
P. Kvasnichka ◽  
Tibor Shipocz ◽  
B. Jarkovska
Keyword(s):  
Biological Membrane ◽  
Lateral Mobility ◽  
Membrane Components

Binding of the alpha-fodrin SH3 domain to the leading lamellae of locomoting chicken fibroblasts

1993 ◽  
Vol 105 (3) ◽  
pp. 647-654
Author(s):  
J. Merilainen ◽  
R. Palovuori ◽  
R. Sormunen ◽  
V.M. Wasenius ◽  
V.P. Lehto
Keyword(s):  
Plasma Membrane ◽  
Cell Polarization ◽  
Glutathione S Transferase ◽  
Src Homology 3 ◽  
Membrane Cytoskeleton ◽  
Cytoplasmic Face ◽  
Small Domain ◽  
Skeletal Protein ◽  
Src Homology ◽  
Membrane Components

Fodrin (nonerythroid spectrin) is a membrane skeletal protein that plays an important role in the establishment and maintenance of the cell shape and polarity. We have identified in alpha-fodrin an src homology 3 (SH3)-related region, a small domain that is present in a large number of proteins that are involved in signal transduction, cell polarization and membrane-cytoskeleton interactions. In this study we have explored the function of the alpha-fodrin SH3 by incubating fixed and permeabilized cultured chicken fibroblasts with the alpha-fodrin SH3 peptide, expressed in bacteria as a fusion protein with glutathione S-transferase. Immunofluorescence and immunoelectron microscopy showed that alpha-fodrin SH3 binds to the cytoplasmic face of the plasma membrane in the leading lamellae and the pseudopodial lobes of the spreading and locomoting cells. No, or only minimal, binding was seen in immotile cells, or in the stationary trailing ends of the locomoting cells. SH3 binding was also seen in cytochalasin-D-treated cells, suggesting that actin filaments are not responsible for the binding. These findings suggest that alpha-fodrin SH3 interacts with plasma membrane components that are present in the leading lamellae exclusively or are modulated in a manner specific to the leading lamellae.

Endocytosis

1997 ◽  
Vol 77 (3) ◽  
pp. 759-803 ◽  
Author(s):  
S. Mukherjee ◽  
R. N. Ghosh ◽  
F. R. Maxfield
Keyword(s):  
Antigen Presentation ◽  
Mammalian Cells ◽  
Membrane Lipids ◽  
Extracellular Fluid ◽  
Cell Polarization ◽  
Receptor Expression ◽  
Cell Surface Receptor ◽  
Coated Pits ◽  
Surface Receptor ◽  
Membrane Components

Mammalian cells take up extracellular material by a variety of different mechanisms that are collectively termed endocytosis. Endocytic mechanisms serve many important cellular functions including the uptake of extracellular nutrients, regulation of cell-surface receptor expression, maintenance of cell polarity, and antigen presentation. Endocytic pathways are also utilized by viruses, toxins, and symbiotic microorganisms to gain entry into cells. One of the best-characterized endocytic mechanisms is receptor-mediated endocytosis via clathrin-coated pits. This type of endocytosis constitutes the major emphasis of this review, with a brief discussion of other endocytic mechanisms and their comparison with the receptor-mediated pathway. This review describes and evaluates critically current understanding of the mechanisms of entry of plasma membrane components such as the receptor-ligand complexes and membrane lipids as well as the extracellular fluid into cells. The intracellular sorting and trafficking of these molecules upon internalization are also described. The roles of endocytosis in physiological and pathological processes are discussed. These include maintenance of cell polarization, antigen presentation, glucose transport, atherosclerosis, Alzheimer's disease, and the endocytosis of toxins and viruses.

Chemotaxis of newt eosinophils: calcium regulation of chemotactic response

1993 ◽  
Vol 265 (6) ◽  
pp. C1527-C1543 ◽  
Author(s):  
R. A. Brundage ◽  
K. E. Fogarty ◽  
R. A. Tuft ◽  
F. S. Fay
Keyword(s):  
Imaging Techniques ◽  
Cell Polarization ◽  
Chemotactic Response ◽  
Microtubule Organizing Center ◽  
Acetoxymethyl Ester ◽  
Heterogeneous Distribution ◽  
Fura 2 ◽  
Organizing Center ◽  
Model Cell ◽  
Chemical Events

Local chemical events underlying chemotaxis were characterized in a new model cell, the newt eosinophil. These cells exhibit a chemotactic response to a trypsin-sensitive component of newt serum. Ca2+ plays a role in this process, since treatments expected to diminish Ca2+ availability from the medium [ethylene glycol-bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, Co2+, and verapamil], to break down transmembrane Ca2+ gradients (ionomycin), or to interfere with the function of intracellular Ca2+ stores (caffeine and neomycin) inhibited cell polarization and movement. Using imaging techniques we found that cytosolic Ca2+ concentration ([Ca2+]i) increased in response to newt serum. Migrating newt eosinophils exhibited a dynamic heterogeneous distribution of [Ca2+]i. [Ca2+]i was elevated in cells undergoing a change of direction relative to cells migrating persistently in one direction. Migrating cells contained gradients of [Ca2+]i along their long axis, with the front of the cell having consistently lower [Ca2+]i than the rear. When cells were loaded with the cell-permeant form of fura 2, fura 2 acetoxymethyl ester, a caffeine-sensitive membrane-delimited region of elevated [Ca2+]i was seen associated with the microtubule organizing center. A model is proposed relating the distribution of [Ca2+]i and the location of the external stimulus to the generation and interaction of substances within the cell that both simulate and inhibit increases in [Ca2+]i.

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