TY - JOUR
T1 - Cell-penetrating peptides
T2 - A reevaluation of the mechanism of cellular uptake
AU - Richard, Jean Philippe
AU - Melikov, Kamran
AU - Vives, Eric
AU - Ramos, Corinne
AU - Verbeure, Birgit
AU - Gait, Mike J.
AU - Chernomordik, Leonid V.
AU - Lebleu, Bernard
PY - 2003/1/3
Y1 - 2003/1/3
N2 - Cellular uptake of a family of cationic cell-penetrating peptides (examples include Tat peptides and penetratin) have been ascribed in the literature to a mechanism that does not involve endocytosis. In this work we reevaluate the mechanisms of cellular uptake of Tat 48-60 and (Arg)9. We demonstrate here that cell fixation, even in mild conditions, leads to the artifactual uptake of these peptides. Moreover, we show that flow cytometry analysis cannot be used validly to evaluate cellular uptake unless a step of trypsin digestion of the cell membrane-adsorbed peptide is included in the protocol. Fluorescence microscopy on live unfixed cells shows characteristic endosomal distribution of peptides. Flow cytometry analysis indicates that the kinetics of uptake are similar to the kinetics of endocytosis. Peptide uptake is inhibited by incubation at low temperature and cellular ATP pool depletion. Similar data were obtained for Tat-conjugated peptide nucleic acids. These data are consistent with the involvement of endocytosis in the cellular internalization of cell-penetrating peptides and their conjugates to peptide nucleic acids.
AB - Cellular uptake of a family of cationic cell-penetrating peptides (examples include Tat peptides and penetratin) have been ascribed in the literature to a mechanism that does not involve endocytosis. In this work we reevaluate the mechanisms of cellular uptake of Tat 48-60 and (Arg)9. We demonstrate here that cell fixation, even in mild conditions, leads to the artifactual uptake of these peptides. Moreover, we show that flow cytometry analysis cannot be used validly to evaluate cellular uptake unless a step of trypsin digestion of the cell membrane-adsorbed peptide is included in the protocol. Fluorescence microscopy on live unfixed cells shows characteristic endosomal distribution of peptides. Flow cytometry analysis indicates that the kinetics of uptake are similar to the kinetics of endocytosis. Peptide uptake is inhibited by incubation at low temperature and cellular ATP pool depletion. Similar data were obtained for Tat-conjugated peptide nucleic acids. These data are consistent with the involvement of endocytosis in the cellular internalization of cell-penetrating peptides and their conjugates to peptide nucleic acids.
UR - http://www.scopus.com/inward/record.url?scp=0346460957&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0346460957&partnerID=8YFLogxK
U2 - 10.1074/jbc.M209548200
DO - 10.1074/jbc.M209548200
M3 - Article
C2 - 12411431
AN - SCOPUS:0346460957
VL - 278
SP - 585
EP - 590
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 1
ER -