Chitin perception in plasmodesmata identifies subcellular, context-specific immune signalling in plants

AbstractThe plasma membrane (PM) that lines plasmodesmata has a distinct protein and lipid composition, underpinning specific regulation of these connections between cells. The plasmodesmal PM can integrate extracellular signals differently from the cellular PM, but it is not known how this specificity is established or how a single stimulus can trigger independent signalling cascades in neighbouring membrane domains. Here we have used the fungal elicitor chitin to investigate signal integration and responses at the plasmodesmal PM. We found that the plasmodesmal PM employs a receptor complex composed of the LysM receptors LYM2 and LYK4 which respectively change their location and interactions in response to chitin. Downstream, signalling is transmitted via a specific phosphorylation signature of an NADPH oxidase and localised callose synthesis that causes plasmodesmata closure. This demonstrates the plasmodesmal PM deploys both plasmodesmata-specific components and differential activation of PM-common components to independently integrate an immune signal.

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Altered 5'-nucleotidase specific activity and distribution between two plasma membrane domains of ascites tumor cells with modified lipid composition

International Journal of Biochemistry ◽

10.1016/0020-711x(88)90010-9 ◽

1988 ◽

Vol 20 (1) ◽

pp. 55-60 ◽

Cited By ~ 5

Author(s):

E.W. Haeffner ◽

S. Seibicke ◽

C.J.K. Hoffmann

Keyword(s):

Plasma Membrane ◽

Tumor Cells ◽

Lipid Composition ◽

Specific Activity ◽

Membrane Domains ◽

Ascites Tumor ◽

Plasma Membrane Domains

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Lipid accumulation promotes scission of caveolae

10.1101/2020.01.22.915173 ◽

2020 ◽

Author(s):

Madlen Hubert ◽

Elin Larsson ◽

Naga Venkata Gayathri Vegesna ◽

Maria Ahnlund ◽

Annika I. Johansson ◽

...

Keyword(s):

Plasma Membrane ◽

Cell Surface ◽

Lipid Composition ◽

Lipid Accumulation ◽

Membrane Lipid ◽

Membrane Domains ◽

Surface Stability ◽

Plasma Membrane Lipid ◽

Restraining Force ◽

Neck Diameter

ABSTRACTCaveolae, bulb-shaped invaginations of the plasma membrane (PM), show distinct behaviors of scission and fusion at the cell surface. Although it is known that caveolae are enriched in cholesterol and sphingolipids, exactly how lipid composition influences caveolae surface stability has not yet been elucidated. Accordingly, we inserted specific lipids into the PM of cells via membrane fusion and studied acute effects on caveolae dynamics. We demonstrate that cholesterol and glycosphingolipids specifically accumulate in caveolae, which decreases their neck diameter and drives their scission from the cell surface. The lipid-induced scission was counteracted by the ATPase EHD2. We propose that lipid accumulation in caveolae generates an intrinsically unstable domain prone to scission if not balanced by the restraining force of EHD2 at the neck. Our work advances the understanding of how lipids contribute to caveolae dynamics, providing a mechanistic link between caveolae and their ability to sense the PM lipid composition.SUMMARYCaveolae serve as mechanoprotectors and membrane buffers but their specific role in sensing plasma membrane lipid composition remains unclear. Hubert et al. show that cholesterol and glycosphingolipids accumulate in caveolae and drive subsequent scission from the cell surface. These results provide new insight into how lipids contribute to budding and scission of membrane domains in cells.

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Membrane microdomains: lessons from microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100140257 ◽

1995 ◽

Vol 53 ◽

pp. 776-777

Author(s):

J.M. Robinson ◽

J.M Oliver

Keyword(s):

Spatial Distribution ◽

Plasma Membrane ◽

Epithelial Cells ◽

Plasma Membranes ◽

Cell Types ◽

Imaging Modalities ◽

Membrane Microdomains ◽

Membrane Domains ◽

Lateral Heterogeneity ◽

Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

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