First step of the cell-penetrating peptide mechanism involves Rac1 GTPase-dependent actin-network remodelling
Version of Record online: 9 JAN 2012
2007 Société Française des Microscopies and Société Biologie Cellulaire de France
Biology of the Cell
Volume 99, Issue 4, pages 223–238, April 2007
How to Cite
Gerbal-Chaloin, S., Gondeau, C., Aldrian-Herrada, G., Heitz, F., Gauthier-Rouvière, C. and Divita, G. (2007), First step of the cell-penetrating peptide mechanism involves Rac1 GTPase-dependent actin-network remodelling. Biology of the Cell, 99: 223–238. doi: 10.1042/BC20060123
- Issue online: 9 JAN 2012
- Version of Record online: 9 JAN 2012
- Received 16 January 2007; Accepted 18 January 2007
- cell-penetrating peptide (CPP);
- cellular uptake mechanism;
- Rac1 GTPase;
Background information. Application of CPPs (cell-penetrating peptides) constitutes a promising strategy for the intracellular delivery of therapeutic molecules. The non-covalent approach based on the amphipathic peptide MPG has been successfully used to improve the delivery of biologically active macromolecules, both in cellulo and in vivo, through a mechanism independent of the endosomal pathway and mediated by the membrane potential.
Results. In the present study, we have investigated the first step of the cellular uptake mechanism of MPG and shown that both MPG and MPG—cargo complexes interact with the extracellular matrix through the negatively charged heparan sulfate proteoglycans. We demonstrated that initiation of cellular uptake constitutes a highly dynamic mechanism where the binding of MPG or the MPG—cargo to the extracellular matrix is rapidly followed by a remodelling of the actin network associated with the activation of the GTPase Rac1. We suggest that MPG-induced clustering of the glycosaminoglycan platform constitutes the ‘onset’ of the cellular uptake mechanism, thereby increasing membrane dynamics and membrane fusion processes. This process favours cell entry of MPG or MPG—DNA complexes, which is further controlled by the ability of MPG to induce a local membrane destabilization.
Conclusions. Although CPPs are taken up through different pathways and mechanisms, the initial step involves electrostatic interactions with the glycosaminoglycan platform, and the dynamics of associated membrane microdomains can be generalized to most non-viral delivery systems.