Exploring membrane organization at varying spatiotemporal resolutions utilizing fluorescence-based approaches: implications in membrane biology

2019 ◽  
Vol 21 (22) ◽  
pp. 11554-11563 ◽  
Author(s):  
Parijat Sarkar ◽  
Amitabha Chattopadhyay
Keyword(s):  
Fluorescence Microscopy ◽  
Membrane Lipids ◽  
Membrane Organization ◽  
Membrane Biology ◽  
Experimental Approaches ◽  
Dynamic Fluorescence

Representative experimental approaches based on dynamic fluorescence microscopy to analyze organization and dynamics of membrane lipids and proteins.

The organization of cell surface membrane domains

1989 ◽  
Vol 47 ◽  
pp. 804-805
Author(s):  
Michael Edidin
Keyword(s):  
Cell Surface ◽  
Membrane Lipids ◽  
Surface Membrane ◽  
Lateral Diffusion ◽  
Cell Types ◽  
Membrane Domains ◽  
Membrane Biology ◽  
Morphological Polarity ◽  
Discrete Domains ◽  
Membrane Components

Cell surface membranes are based on a fluid lipid bilayer and models of the membranes' organization have emphasised the possibilities for lateral motion of membrane lipids and proteins within the bilayer. Two recent trends in cell and membrane biology make us consider ways in which membrane organization works against its inherent fluidity, localizing both lipids and proteins into discrete domains. There is evidence for such domains, even in cells without obvious morphological polarity and organization [Table 1]. Cells that are morphologically polarised, for example epithelial cells, raise the issue of membrane domains in an accute form.The technique of fluorescence photobleaching and recovery, FPR, was developed to measure lateral diffusion of membrane components. It has also proven to be a powerful tool for the analysis of constraints to lateral mobility. FPR resolves several sorts of membrane domains, all on the micrometer scale, in several different cell types.

scholarly journals Exofacial membrane composition and lipid metabolism regulates plasma membrane P4-ATPase substrate specificity

2020 ◽  
Author(s):  
Bartholomew P. Roland ◽  
Bhawik K. Jain ◽  
Todd R. Graham
Keyword(s):  
Plasma Membrane ◽  
Membrane Lipids ◽  
Asymmetric Distribution ◽  
Membrane Composition ◽  
Membrane Biology ◽  
Membrane Asymmetry ◽  
Type Iv ◽  
Lipid Species ◽  
Endogenous Lipid ◽  
A Cell

AbstractThe plasma membrane of a cell is characterized by an asymmetric distribution of lipid species across the exofacial and cytofacial aspects of the bilayer. The regulation of membrane asymmetry is a fundamental characteristic of membrane biology, and is crucial for signal transduction, vesicle transport, and cell division. The type-IV family of P-ATPases, or P4-ATPases, establish membrane asymmetry by selection and transfer of a subset of membrane lipids from the lumenal or exofacial leaflet to the cytofacial aspect of the bilayer. It is still unclear how these enzymes sort through the spectrum of lipids within the membrane to identify their desired substrate(s) and how the membrane environment modulates this activity. Therefore, we tested how the yeast plasma membrane P4-ATPase, Dnf2, responds to changes in membrane composition induced by perturbation of endogenous lipid biosynthetic pathways or exogenous application of lipid. The primary substrates of Dnf2 are two chemically divergent lipids, glucosylceramide (GlcCer) and phosphatidylcholine ((PC) or their lyso-lipid derivatives), and we find that these substrates compete with each other for transport. Acutely inhibiting sphingolipid synthesis using myriocin attenuates transport of exogenously applied GlcCer without perturbing PC transport. Deletion of genes controlling later steps of glycosphingolipid production also perturb GlcCer transport to a greater extent than PC transport. Surprisingly, application of lipids that are poor transport substrates differentially affect PC and GlcCer transport by Dnf2, thus altering substrate preference. Our data indicate that Dnf2 exhibits exquisite sensitivity to the membrane composition; thus, providing feedback onto the function of the P4-ATPases.

scholarly journals Phosphatidylcholine biosynthesis in Mitis group streptococci via host metabolite scavenging

2019 ◽  
Author(s):  
Luke R. Joyce ◽  
Ziqiang Guan ◽  
Kelli L. Palmer
Keyword(s):  
Membrane Lipids ◽  
Cellular Membrane ◽  
Human Pathogen ◽  
Opportunistic Pathogens ◽  
Membrane Biology ◽  
Host Interactions ◽  
Fundamental Information ◽  
Phosphatidylcholine Biosynthesis ◽  
Health And Disease ◽  
Mechanistic Basis

AbstractThe Mitis group streptococci include the major human pathogenStreptococcus pneumoniaeand the opportunistic pathogensS. mitisandS. oraliswhich are human oral cavity colonizers and agents of bacteremia and infective endocarditis in immunocompromised patients. Bacterial membrane lipids play crucial roles in microbe-host interactions, yet for many pathogens, the composition of the membrane is poorly understood. In this study, we characterized the lipidomes of selected species of Mitis group streptococci and investigated the mechanistic basis for biosynthesis of the phospholipid phosphatidylcholine (PC). PC is a major lipid in eukaryotic cellular membranes, but it is considered to be comparatively rare in bacterial taxa. Using liquid chromatography/mass spectrometry (LC/MS) in conjunction with stable isotope tracing, we determined that Mitis group streptococci synthesize PC via the rare host metabolite scavenging pathway, the glycerophosphocholine (GPC) pathway, which is largely uncharacterized in bacteria. Our work demonstrates that Mitis group streptococci includingS. pneumoniaeremodel their membrane in response to the major human metabolites GPC and lysoPC.ImportanceWe lack fundamental information about the composition of the cellular membrane even for the best studied pathogens of critical significance for human health. The Mitis group streptococci are closely linked to humans in health and disease, yet their membrane biology is poorly understood. Here, we demonstrate that these streptococci scavenge major human metabolites and use them to synthesize the membrane phospholipid phosphatidylcholine. Our work is significant because it identifies a mechanism by which the major human pathogenS. pneumoniaeand the primary human oral colonizersS. mitisandS. oralisremodel their membrane in response to host metabolites.

scholarly journals Phosphatidylcholine Biosynthesis in Mitis Group Streptococci via Host Metabolite Scavenging

2019 ◽  
Vol 201 (22) ◽  
Author(s):  
Luke R. Joyce ◽  
Ziqiang Guan ◽  
Kelli L. Palmer
Keyword(s):  
Membrane Lipids ◽  
Cellular Membrane ◽  
Human Pathogen ◽  
Content Type ◽  
Membrane Biology ◽  
Host Interactions ◽  
Fundamental Information ◽  
Phosphatidylcholine Biosynthesis ◽  
Health And Disease ◽  
Mechanistic Basis

ABSTRACT The mitis group streptococci include the major human pathogen Streptococcus pneumoniae and the opportunistic pathogens Streptococcus mitis and Streptococcus oralis, which are human oral cavity colonizers and agents of bacteremia and infective endocarditis in immunocompromised patients. Bacterial membrane lipids play crucial roles in microbe-host interactions; for many pathogens, however, the composition of the membrane is poorly understood. In this study, we characterized the lipidomes of selected species of mitis group streptococci and investigated the mechanistic basis for biosynthesis of the phospholipid phosphatidylcholine (PC). PC is a major lipid in eukaryotic cellular membranes, but it is considered to be comparatively rare in bacterial taxa. Using liquid chromatography-mass spectrometry in conjunction with stable isotope tracing, we determined that mitis group streptococci synthesize PC via a rare host-metabolite-scavenging pathway, the glycerophosphocholine (GPC) pathway, which is largely uncharacterized in bacteria. Our work demonstrates that mitis group streptococci, including S. pneumoniae, remodel their membranes in response to the major human metabolites GPC and lysophosphatidylcholine. IMPORTANCE We lack fundamental information about the composition of the cellular membrane even for the best-studied pathogens of critical significance for human health. The mitis group streptococci are closely linked to humans in health and disease, but their membrane biology is poorly understood. Here, we demonstrate that these streptococci scavenge major human metabolites and use them to synthesize the membrane phospholipid PC. Our work is significant because it identifies a mechanism by which the major human pathogen S. pneumoniae and the primary human oral colonizers S. mitis and S. oralis remodel their membranes in response to host metabolites.

Lipid domain association of influenza virus proteins detected by dynamic fluorescence microscopy techniques

2012 ◽  
Vol 15 (2) ◽  
pp. 179-189 ◽  
Author(s):  
Michael Veit ◽  
Stephanie Engel ◽  
Bastian Thaa ◽  
Silvia Scolari ◽  
Andreas Herrmann
Keyword(s):  
Influenza Virus ◽  
Fluorescence Microscopy ◽  
Lipid Domain ◽  
Microscopy Techniques ◽  
Dynamic Fluorescence ◽  
Virus Proteins
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