Journal of Biological Chemistry
Volume 275, Issue 49, 8 December 2000, Pages 38640-38644
Journal home page for Journal of Biological Chemistry

MEMBRANE TRANSPORT STRUCTURE FUNCTION AND BIOGENESIS
The Lipids C2- and C16-Ceramide Form Large Stable Channels: IMPLICATIONS FOR APOPTOSIS*

https://doi.org/10.1074/jbc.C000587200Get rights and content
Under a Creative Commons license
open access

We report that physiological concentrations of both short- and long-chain ceramides, despite being lipids, form large stable pores in membranes. Some of these pores should be large enough to allow cytochrome c to permeate. Dihydroceramide differs from ceramide by the reduction of one double bond, and yet both its apoptogenic and channel-forming activities are greatly reduced. A structural model provides insight into how ceramides might form pores. According to a mathematical model, both the individual conductance of the channels and the overall membrane conductance are directly related to the overall concentration of ceramide in the membrane. Slight changes in concentration have dramatic effects on the size of the channels formed, providing an easy way for rapidly altering membrane permeability by changing the activity of local synthetic and catabolic enzymes. A possible role for these channels in apoptosis is discussed.

Cited by (0)

Published, JBC Papers in Press, October 10, 2000, DOI 10.1074/jbc.C000587200

*

The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

To whom correspondence and requests for materials should be addressed: E-mail: [email protected].