title: Metabolic energy-independent mechanism of internalization for the cell penetrating peptide penetratin.
abstract: Cellular uptake of vector peptides used for internalization of hydrophilic molecules into cells is known to follow two different pathways: direct translocation of the plasma membrane and internalization by endocytosis followed by release into the cytosol. These pathways differ in their energy dependence. The first does not need metabolic energy while the second requires metabolic energy. Herein we used erythrocytes and plasma membrane vesicles to study membrane perturbations induced by the cell penetrating peptide penetratin. The results show that cell penetrating peptides are able to be internalized by two metabolic energy-independent pathways: direct crossing of the plasma membrane and endocytosis-like mechanisms. The last mechanism involves the induction of membrane negative curvature resulting in invaginations that mimic the endosomal uptake in the absence of ATP. This new mechanism called "physical endocytosis" or "self-induced endocytosis" might explain different data concerning the independence or dependence on metabolic energy during cellular uptake and reveals the autonomous capacity of peptides to induce their internalization.
authors.affiliation: CNRS, UMR 7203, Laboratoire des Biomolécules, Groupe N. J. Conté, Paris, France.
authors.forename: Ofelia
authors.initials: O
authors.lastname: Maniti
authors.forename: Elise
authors.initials: E
authors.lastname: Blanchard
authors.forename: Germain
authors.initials: G
authors.lastname: Trugnan
authors.forename: Antonin
authors.initials: A
authors.lastname: Lamazière
authors.forename: Jesus
authors.initials: J
authors.lastname: Ayala-Sanmartin
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D057846:Cell-Penetrating Peptides; D004285:Dogs; D004705:Endocytosis; D004734:Energy Metabolism; D004912:Erythrocytes / Q000378:metabolism; D018613:Microscopy, Confocal
chemical_list: D002352:Carrier Proteins; D057846:Cell-Penetrating Peptides; D000255:Adenosine Triphosphate; C414409:penetratin