Basic cell penetrating peptides induce plasma membrane positive curvature, lipid domain separation and protein redistribution.

Basic cell penetrating peptides are tools for molecular cellular internalization of nonmembrane permeable molecules. Their uptake mechanisms involve energy-dependent and energy-independent pathways such as endocytosis, direct translocation or physical endocytosis. These mechanisms are ruled by both, the peptides physicochemical properties and structure and by the membrane lipids characteristics and organization.

Lipid organization regulates annexin A2 Ca(2+)-sensitivity for membrane bridging and its modulator effects on membrane fluidity.

Annexin A2 (AnxA2) is a phospholipid binding protein that has been implicated in many membrane-related cellular functions. AnxA2 is able to bind different acidic phospholipids such as phosphatidylserine (PS) and phosphatidylinositol-4,5-bisphosphate (PI2P). This binding is mediated by Ca(2+)-dependent and Ca(2+)-independent mechanisms.