Related Experiment Video
Updated: Aug 13, 2026
Investigating the Spreading and Toxicity of Prion-like Proteins Using the Metazoan Model Organism C. elegans
Published on: January 8, 2015
A genome-wide CRISPR screen implicates plasma membrane asymmetry in exogenous C6-ceramide toxicity
Siti Nur Sarah Morris1,2, Kirandeep K Deol1,2, Mike Lange1,2
1Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
Abstract:
The bioactive sphingolipid ceramide impacts diverse cellular processes (e.g. apoptosis and cell proliferation) through its effects on membrane dynamics and intracellular signaling pathways. The dysregulation of ceramide metabolism has been implicated in cancer evasion of apoptosis and targeting ceramide metabolism has potential therapeutic benefits as a strategy to kill cancer cells and slow tumor growth. However, the mechanisms of cancer cell resistance to ceramide-mediated cell death are vastly intertwined and incompletely understood. To shed light on this mystery, we performed a genome-wide CRISPR-Cas9 screen to systematically identify regulators of cancer resistance to the soluble short chain ceramide, C6 ceramide (C6-Cer). Our results reveal a complex landscape of genetic modifiers of C6-Cer toxicity, including genes associated with ceramide and sphingolipid metabolism, vesicular trafficking, and membrane biology. Furthermore, we find that loss of the phospholipid flippase subunit TMEM30A impairs the plasma membrane trafficking of its binding partner, the P4-type ATPase ATP11B, and depletion of TMEM30A or ATP11B disrupts plasma membrane asymmetry and promotes resistance to C6-Cer toxicity. Together, our findings provide a resource of genetic modifiers of C6-Cer toxicity and reveal an unexpected role of plasma membrane asymmetry in C6-Cer induced cell death.
Insights
Cancer cells resist ceramide-induced death through complex genetic mechanisms. Loss of TMEM30A or ATP11B disrupts membrane asymmetry, promoting this resistance, offering new therapeutic targets.
Area of Science:
- Cell Biology
- Biochemistry
- Cancer Research
Background:
- Ceramide, a bioactive sphingolipid, regulates cell processes like apoptosis and proliferation.
- Dysregulated ceramide metabolism is linked to cancer's evasion of apoptosis, making it a therapeutic target.
- Mechanisms of cancer cell resistance to ceramide-mediated death are complex and poorly understood.
Purpose of the Study:
- To identify genetic regulators of cancer cell resistance to C6 ceramide (C6-Cer).
- To elucidate the role of plasma membrane asymmetry in ceramide toxicity.
Main Methods:
- Genome-wide CRISPR-Cas9 screening was employed to identify resistance regulators.
- Investigated the function of TMEM30A and its interaction with ATP11B.
- Assessed the impact of TMEM30A/ATP11B depletion on plasma membrane asymmetry and C6-Cer sensitivity.
Main Results:
- A wide range of genetic modifiers of C6-Cer toxicity were identified, including genes in sphingolipid metabolism and membrane trafficking.
- Loss of TMEM30A impairs ATP11B trafficking to the plasma membrane.
- Depletion of TMEM30A or ATP11B disrupts plasma membrane asymmetry and confers resistance to C6-Cer.
Conclusions:
- The study provides a comprehensive resource of genetic modifiers influencing C6-Cer toxicity.
- Plasma membrane asymmetry plays a critical, previously unrecognized role in ceramide-induced cell death.
- Targeting TMEM30A/ATP11B and plasma membrane asymmetry may offer novel cancer therapeutic strategies.
