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Regulation of PLCβ2 by the electrostatic and mechanical properties of lipid bilayers.

Arduin A, Gaffney PR, Ces O - Sci Rep (2015)

Bottom Line: However, the regulatory mechanism of PLC is not yet understood in detail.Evidence was found for a direct interaction between PLC and the GTPases that mediate phospholipase activation.PLC activity was found to depend upon the electrostatic potential and the stored curvature elastic stress of the lipid membranes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemical Biology, Department of Chemical Biology, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom.

ABSTRACT
Phosphoinositide-specific phospholipase C (PLC) is an important family of enzymes constituting a junction between phosphoinositide lipid signaling and the trans-membrane signal transduction processes that are crucial to many living cells. However, the regulatory mechanism of PLC is not yet understood in detail. To address this issue, activity studies were carried out using lipid vesicles in a model system that was specifically designed to study protein-protein and lipid-protein interactions in concert. Evidence was found for a direct interaction between PLC and the GTPases that mediate phospholipase activation. Furthermore, for the first time, the relationships between PLC activity and substrate presentation in lipid vesicles of various sizes, as well as lipid composition and membrane mechanical properties, were analyzed. PLC activity was found to depend upon the electrostatic potential and the stored curvature elastic stress of the lipid membranes.

No MeSH data available.


Related in: MedlinePlus

The effect on PLCβ2 activity of lipid bilayer curvature.The bar chart shows the average activity measured in duplicate samples (± the s.e.m.). The activity was monitored using the cell-free system and with lipid vesicles of different sizes. The lipid vesicles were prepared by extrusion using various pore size filters (50, 100, 400 nm) or by sonication. The samples contained: purified PLCβ2 (0.25 ng/μl, equivalent to 2.7 nM). All other conditions are the same as for Fig. 2.
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f4: The effect on PLCβ2 activity of lipid bilayer curvature.The bar chart shows the average activity measured in duplicate samples (± the s.e.m.). The activity was monitored using the cell-free system and with lipid vesicles of different sizes. The lipid vesicles were prepared by extrusion using various pore size filters (50, 100, 400 nm) or by sonication. The samples contained: purified PLCβ2 (0.25 ng/μl, equivalent to 2.7 nM). All other conditions are the same as for Fig. 2.

Mentions: Lipid vesicles (DOPE: PtdIns(4,5)P2/[3H]-PtdIns(4,5)P2 16:1 mol/mol) of different diameters (50, 100 and 400 nm), and therefore of different membrane curvatures, were obtained by extrusion and their normal distribution was confirmed by dynamic light scattering. The data generated at this stage showed no significant variation in PLCβ2 activity in the presence of GDP and GG-Rac2, and no variation in PLCβ2 (2–803 AA) stimulation (3-fold) in the presence of GTPγS and GG-Rac2 using lipid vesicles of different membrane curvature (Fig. 4).


Regulation of PLCβ2 by the electrostatic and mechanical properties of lipid bilayers.

Arduin A, Gaffney PR, Ces O - Sci Rep (2015)

The effect on PLCβ2 activity of lipid bilayer curvature.The bar chart shows the average activity measured in duplicate samples (± the s.e.m.). The activity was monitored using the cell-free system and with lipid vesicles of different sizes. The lipid vesicles were prepared by extrusion using various pore size filters (50, 100, 400 nm) or by sonication. The samples contained: purified PLCβ2 (0.25 ng/μl, equivalent to 2.7 nM). All other conditions are the same as for Fig. 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525138&req=5

f4: The effect on PLCβ2 activity of lipid bilayer curvature.The bar chart shows the average activity measured in duplicate samples (± the s.e.m.). The activity was monitored using the cell-free system and with lipid vesicles of different sizes. The lipid vesicles were prepared by extrusion using various pore size filters (50, 100, 400 nm) or by sonication. The samples contained: purified PLCβ2 (0.25 ng/μl, equivalent to 2.7 nM). All other conditions are the same as for Fig. 2.
Mentions: Lipid vesicles (DOPE: PtdIns(4,5)P2/[3H]-PtdIns(4,5)P2 16:1 mol/mol) of different diameters (50, 100 and 400 nm), and therefore of different membrane curvatures, were obtained by extrusion and their normal distribution was confirmed by dynamic light scattering. The data generated at this stage showed no significant variation in PLCβ2 activity in the presence of GDP and GG-Rac2, and no variation in PLCβ2 (2–803 AA) stimulation (3-fold) in the presence of GTPγS and GG-Rac2 using lipid vesicles of different membrane curvature (Fig. 4).

Bottom Line: However, the regulatory mechanism of PLC is not yet understood in detail.Evidence was found for a direct interaction between PLC and the GTPases that mediate phospholipase activation.PLC activity was found to depend upon the electrostatic potential and the stored curvature elastic stress of the lipid membranes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemical Biology, Department of Chemical Biology, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom.

ABSTRACT
Phosphoinositide-specific phospholipase C (PLC) is an important family of enzymes constituting a junction between phosphoinositide lipid signaling and the trans-membrane signal transduction processes that are crucial to many living cells. However, the regulatory mechanism of PLC is not yet understood in detail. To address this issue, activity studies were carried out using lipid vesicles in a model system that was specifically designed to study protein-protein and lipid-protein interactions in concert. Evidence was found for a direct interaction between PLC and the GTPases that mediate phospholipase activation. Furthermore, for the first time, the relationships between PLC activity and substrate presentation in lipid vesicles of various sizes, as well as lipid composition and membrane mechanical properties, were analyzed. PLC activity was found to depend upon the electrostatic potential and the stored curvature elastic stress of the lipid membranes.

No MeSH data available.


Related in: MedlinePlus