title: Translocation of cell-penetrating peptides across the plasma membrane is controlled by cholesterol and microenvironment created by membranous proteins.
abstract: Despite the extensive research in the field of CPPs' cell entry the exact mechanisms underlying their cellular uptake and the role of involved cell surface molecules in the internalization process have remained controversial. The present study focused on the interactions between CPPs and plasma membrane compounds using giant plasma membrane vesicles (GPMVs). GPMVs have shown to be a suitable model to study the translocation of CPPs across the plasma membrane in conditions lacking endocytosis. Our results show that higher cholesterol content and tighter packing of membrane predominantly reduce the accumulation of transportan, TP10 and model amphipathic peptide (MAP) in vesicles, indicating that the internalization of CPPs takes place preferentially via the more dynamic membrane regions. The partial digestion of membrane proteins from GPMVs' surface, on the other hand, drastically reduced the accumulation of nona-arginine and Tat peptide into vesicles, suggesting that proteins play a crucial role in the uptake of arginine-rich CPPs.
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
authors.forename: Janely
authors.initials: J
authors.lastname: Pae
authors.affiliation: Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.
authors.forename: Pille
authors.initials: P
authors.lastname: Säälik
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
authors.forename: Laura
authors.initials: L
authors.lastname: Liivamägi
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Lubenets
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Piret
authors.initials: P
authors.lastname: Arukuusk
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia; Department of Neurochemistry, Stockholm University, Stockholm, Sweden.
authors.forename: Ülo
authors.initials: Ü
authors.lastname: Langel
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia. Electronic address: mpooga@ut.ee.
authors.forename: Margus
authors.initials: M
authors.lastname: Pooga
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability; D057846:Cell-Penetrating Peptides / Q000737:chemistry / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism*; D004705:Endocytosis; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D051381:Rats
chemical_list: D057846:Cell-Penetrating Peptides; D008565:Membrane Proteins; D002784:Cholesterol
keywords: Cell-penetrating peptide; Direct translocation; Nona-arginine; Plasma membrane vesicles; Tat peptide; Transportan