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Efficient entry of cell-penetrating peptide nona-arginine into adherent cells involves a transient increase in intracellular calcium.
- Source :
-
Biochemical Journal . 10/15/2015, Vol. 471 Issue 2, p221-230. 10p. - Publication Year :
- 2015
-
Abstract
- Understanding the mechanism of entry of cationic peptides such as nona-arginine (R9) into cells remains an important challenge to their use as efficient drug-delivery vehicles. At nanomolar to low micromolar R9 concentrations and at physiological temperature, peptide entry involves endocytosis. In contrast, at a concentration ≽10 µM,R9 induces a very effective non-endocytic entry pathway specific for cationic peptides. We found that a similar entry pathway is induced at 1-2 µM concentrations of R9 if peptide application is accompanied by a rapid temperature drop to 15°C. Both at physiological and at sub-physiological temperatures, this entry mechanism was inhibited by depletion of the intracellular ATP pool. Intriguingly, we found that R9 at 10-20 µM and 37°C induces repetitive spikes in intracellular Ca2+ concentration. This Ca2+ signalling correlated with the efficiency of the peptide entry. Pre-loading cells with the Ca2+ chelator BAPTA(1,2-bis(oaminophenoxy) ethane-N,N,N',N'-tetraacetic acid) inhibited both Ca2+ spikes and peptide entry, suggesting that an increase in intracellular Ca2+ precedes and is required for peptide entry. One of the hallmarks of Ca2+ signalling is a transient cell-surface exposure of phosphatidylserine (PS), a lipid normally residing only in the inner leaflet of the plasma membrane. Blocking the accessible PS with the PS-binding domain of lactadherin strongly inhibited non-endocytic R9 entry, suggesting the importance of PS externalization in this process. To conclude, we uncovered a novel mechanistic link between calcium signalling and entry of cationic peptides. This finding will enhance our understanding of the properties of plasma membrane and guide development of future drug-delivery vehicles. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02646021
- Volume :
- 471
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Biochemical Journal
- Publication Type :
- Academic Journal
- Accession number :
- 110123655
- Full Text :
- https://doi.org/10.1042/BJ20150272