Sticholysin recognition of ceramide-phosphoethanolamine
Carmen García-Montoya1, Diego Heras-Márquez1, Rafael Amigot-Sánchez1
1Departamento de Bioquímica y Biología Molecular, Facultades de Ciencias Biológicas y Ciencias Químicas, Universidad Complutense, Madrid, Spain.
Archives of Biochemistry and Biophysics
|May 19, 2023
Summary
Sea anemone toxins, actinoporins, bind cell membranes. Researchers found these toxins also recognize ceramide-phosphoethanolamine (CPE) lipids, similar to sphingomyelin, expanding understanding of toxin-lipid interactions.
Area of Science:
- Biochemistry
- Molecular Biology
- Toxicology
Background:
- Actinoporins are sea anemone pore-forming toxins.
- Sphingomyelin (SM) is a known lipid receptor for actinoporins.
- The role of ceramide-phosphoethanolamine (CPE) in actinoporin binding was unclear.
Purpose of the Study:
- To investigate if actinoporins recognize ceramide-phosphoethanolamine (CPE) as a lipid receptor.
- To determine if cholesterol is required for CPE recognition by actinoporins.
Main Methods:
- Used sticholysins from Stichodactyla helianthus.
- Tested actinoporin activity on liposomes composed of phosphatidylcholine (PC) and CPE, with and without cholesterol.
- Measured calcein release from vesicles as an indicator of pore formation.
Main Results:
- Sticholysins induced calcein release from PC:CPE vesicles lacking cholesterol.
- This activity was comparable to that observed on PC:SM membranes.
- Demonstrated that CPE can act as a lipid receptor for actinoporins independently of cholesterol.
Conclusions:
- Actinoporins can recognize and bind to ceramide-phosphoethanolamine (CPE) in cell membranes.
- Cholesterol is not required for CPE recognition by actinoporins.
- These findings expand the known lipid interactions of actinoporins.
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