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Updated: Jul 28, 2026
13:54
Preparation of Cell-lines for Conditional Knockdown of Gene Expression and Measurement of the Knockdown Effects on E4orf4-Induced Cell Death
Published on: October 21, 2012
Functional expression cloning reveals proapoptotic role for protein phosphatase 4.
M Mourtada-Maarabouni1, L Kirkham, B Jenkins
1School of Life Sciences, Keele University, Keele, T5 5BG, UK.
Cell Death and Differentiation
|August 23, 2003
Summary
Functional expression cloning identified protein phosphatase 4 (PP4) as a key regulator of apoptosis. Downregulating PP4 in T lymphocytes conferred resistance to cell death induced by dexamethasone and UV radiation, suggesting a proapoptotic role.
Area of Science:
- Molecular Biology
- Cell Biology
- Immunology
Background:
- Apoptosis, or programmed cell death, is critical for T lymphocyte homeostasis.
- Understanding the molecular mechanisms controlling apoptosis is essential for immune system regulation.
- Functional expression cloning offers a powerful, unbiased approach to identify novel apoptosis regulators.
Purpose of the Study:
- To identify novel proteins involved in the control of apoptosis using functional expression cloning.
- To investigate the role of protein phosphatase 4 (PP4) in T lymphocyte survival and death pathways.
Main Methods:
- Applied functional expression cloning to isolate cDNAs conferring resistance to dexamethasone and gamma-irradiation.
- Utilized transfection with a partial PP4 cDNA in an expression vector.
- Assessed cellular resistance using membrane integrity and colony-forming assays.
Main Results:
- Successfully isolated a partial cDNA for the catalytic subunit of protein phosphatase 4 (PP4).
- Transfection with PP4 cDNA led to PP4 downregulation and conferred resistance to dexamethasone and UV radiation.
- Demonstrated resistance through membrane integrity and colony-forming assays.
Conclusions:
- Protein phosphatase 4 (PP4) plays a significant proapoptotic role in T lymphocytes.
- PP4 is a critical mediator in the cellular decision between survival and death.
- Targeting PP4 may offer therapeutic strategies for modulating T cell apoptosis.
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