title: Cellular uptake of arginine-rich peptides: roles for macropinocytosis and actin rearrangement.
abstract: The use of membrane-permeable peptides as carrier vectors for the intracellular delivery of various proteins and macromolecules for modifying cellular function is well documented. Arginine-rich peptides, including those derived from human immunodeficiency virus 1 Tat protein, are among the representative classes of these vectors. The internalization mechanism of these vector peptides and their protein conjugates was previously regarded as separate from endocytosis, but more recent reevaluations have concluded that endocytosis is involved in their internalization. In this report, we show that the uptake of octa-arginine (R8) peptide by HeLa cells was significantly suppressed by the macropinocytosis inhibitor ethylisopropylamiloride (EIPA) and the F-actin polymerization inhibitor cytochalasin D, suggesting a role for macropinocytosis in the uptake of the peptide. In agreement with this we observed that treatment of the cells with R8 peptide induced significant rearrangement of the actin cytoskeleton. The internalization efficiency and contribution of macropinocytosis were also observed to have a dependency on the chain length of the oligoarginine peptides. Uptake of penetratin, another representative peptide carrier, was less sensitive to EIPA and penetratin did not have such distinct effects on actin localization. The above observations suggest that penetratin and R8 peptides have distinct internalization mechanisms.
authors.affiliation: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
authors.forename: Ikuhiko
authors.initials: I
authors.lastname: Nakase
authors.forename: Miki
authors.initials: M
authors.lastname: Niwa
authors.forename: Toshihide
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sonomura
authors.forename: Noriko
authors.initials: N
authors.lastname: Kawabata
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Koike
authors.forename: Masanori
authors.initials: M
authors.lastname: Takehashi
authors.forename: Seigo
authors.initials: S
authors.lastname: Tanaka
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Ueda
authors.forename: Jeremy C
authors.initials: JC
authors.lastname: Simpson
authors.forename: Arwyn T
authors.initials: AT
authors.lastname: Jones
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sugiura
authors.forename: Shiroh
authors.initials: S
authors.lastname: Futaki
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D001120:Arginine / Q000032:analysis*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D057846:Cell-Penetrating Peptides; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D010873:Pinocytosis; D021381:Protein Transport
chemical_list: D000199:Actins; D002352:Carrier Proteins; D057846:Cell-Penetrating Peptides; D009842:Oligopeptides; D010455:Peptides; C500307:octa-arginine peptide; D001120:Arginine; C414409:penetratin