doi:10.1038/nindia.2015.58 Published online 7 May 2015
An interdisciplinary team of scientists has unraveled the underlying mechanism through which information is transmitted across the inner and outer layers of the cell membrane by phosphatidylserine (PS), an important phospholipid component of this membrane1.
The cell receives external cues from the environment from lipid-linked receptors on the outer surface of the cell membrane. The mechanism of this information relay was not clear till now.The researchers combined various techniques to understand the role of PS in the formation of nanoclusters of lipids, a process essential for a number of cell signaling events.
Previous work from the group had established that the actin cytoskeleton played a crucial role in nanocluster formation. How these lipids on the outer leaflet of the cell membrane “talk” to the actin beneath the inner leaflet was unclear.
Experiments showed that long-acyl chain lipid species were more likely to form nanoclusters.The researchers then identified particular lipids in the inner leaflet that have acyl-chain interactions on one hand, and bind to the actin via proteins on the other.
“By selectively masking potential candidates, we zeroed in on PS, in particular long acyl-chain PS. This is recruited in a context-dependent manner to support communication between the inner and outer leaflets of the cell membrane” says Anupama Ambika Anilkumar, one of the authors.