Researcher Reviews Ionic Protein-lipid Interaction at The Plasma Membrane

Acidic phospholipids are minor phospholipid species on the biomembrane, but they have important physiological functions. A growing number of studies show that acidic phospholipids can regulate protein structure and function through its ionic interaction with proteins via polybasic sequences.

Prof. XU Chenqi from the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, CAS was invited to review the ionic protein–lipid interaction at the plasma membrane (PM). This review summarizes five mechanisms in the regulation of protein by acidic phospholipids. They are the targeting of cytoplasmic soluble proteins to the PM, the mediation of cross-membrane protein interactions, the induction of membrane protein clustering, the sequestration of protein functional sites, and regulation of protein conformations. At the end of the article, the regulation of ionic protein–lipid interactions by calcium was discussed. Calcium can neutralize the negative charge of acidic phospholipids, regulate the local concentrations of acidic phospholipids and activate calmodulin to repel polybasic proteins from the PM. The review entitled “Ionic protein–lipid interaction at the plasma membrane: what can the charge do?” was published online in Trends in Biochemical Sciences on Feb 15, 2014.

XU Chenqi’s lab focuses on the study of T cell signaling. They found that TCR functional sites can be sequestrated via ionic protein-lipid interaction (Xu et al, 2008, Cell). Calcium can neutralize the negative charge of acidic phospholipids and disrupt this interaction (Shi et al, 2013, Nature). They also collaborated with other groups and found that ionic protein-lipid interaction plays an important role in the regulation of EGFR and BCR. Research in XU Chenqi’s group was funded by Ministry of Science & Technology of China, National Natural Science Foundation of China, and Shanghai Municipality.