Keeping the opening wide during membrane enclosure
How can a growing membrane keep enough room to take in cell material?
How it works
During autophagy, a growing membrane surrounds material that a cell needs to recycle. The membrane must not only grow; its opening also needs to remain wide enough for the material to enter.
An open edge costs energy to maintain, so a membrane may tend to close too early. A 2023 study showed that a sorting nexin protein complex gathered at the edge of the growing membrane helps keep that opening wide.
When this control is lost, autophagosomes of nearly normal size can still form, but they are less able to enclose large pieces of cellular material. The size of the opening, not just the size of the membrane, therefore affects what can be recycled.
What we want to learn next
Published researchWe next want to understand how the amount of protein at the edge and the membrane’s flexibility together determine the opening size and the timing of closure.
Related publications & press releases
This research identifies a mechanism that helps keep the growing membrane open for efficient enclosure of cellular material.
Three-dimensional measurements and physical modeling reveal characteristic shapes formed as autophagosomes grow.