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Updated: Jun 19, 2026
08:49
Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes
Published on: March 14, 2021
Phospholipase D modulation by ceramide in senescence.
Lisa M Webb1, Alan T Arnholt, Mark E Venable
1Biology Department, Appalachian State University, Boone, NC 28608-2027, USA.
Molecular and Cellular Biochemistry
|October 27, 2009
Summary
Senescent cells exhibit reduced Phospholipase D (PLD) activity due to a defective membrane component. Ceramide, a sphingolipid, mediates this inhibition, impacting cellular regulation.
Area of Science:
- Cellular senescence
- Enzymology
- Molecular biology
Background:
- Phospholipase D (PLD) plays a role in cell division and its activity decreases in senescent cells.
- Replicative senescence affects cellular functions, including PLD activity.
Purpose of the Study:
- To investigate the cause of reduced Phospholipase D activity in senescent cells.
- To identify the specific cellular component responsible for PLD dysfunction during senescence.
Main Methods:
- Fractionation of cellular components from senescent and low-passage human cells.
- Recombination experiments to assess PLD activation with different cell fractions.
- Treatment with ceramide to evaluate its effect on PLD activity.
Main Results:
- Senescent cells displayed significantly lower PLD activatability compared to young cells.
- Cytosolic components were essential for optimal PLD activation.
- A defective membrane component in senescent cells impaired PLD activation, potentially involving the PLD enzyme, PKC, or ARF.
- Ceramide treatment reduced PLD activity, suggesting it mediates the inhibition.
Conclusions:
- The membrane component's defect in activating PLD is a key factor in cellular senescence.
- Ceramide acts as a mediator for PLD inhibition during senescence.
- Understanding these mechanisms is crucial for comprehending cellular aging and regulation.
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