COPA and SLC4A4 are required for cellular entry of arginine-rich peptides.
Cell-penetrating peptides (CPPs) have gained attention as promising tools to enable the delivery of various molecules in a non-invasive manner. Among the CPPs, TAT and poly-arginine have been extensively utilized in numerous studies for the delivery of functional proteins, peptides, and macromolecules to analyze cellular signaling. However, the molecular mechanisms of cellular entry remain largely unknown. Here, we applied siRNA library screening to identify the regulatory genes for the cellular entry of poly-arginine peptide based on microscopic observation of the entry of fluorescent peptides in siRNA-treated cells. In this screening, we identified the cell membrane gene SLC4A4 and the trafficking regulator gene COPA, which also plays an important role in early endosome maturation. These results demonstrated that cellular entry of poly-arginine requires at least two different steps, probably binding on the cell surface and endosomal entry. The identification of genes for cellular entry of poly-arginine provides insights into its mechanisms and should further aid in the development of highly efficient cell-penetrating peptides.
Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Tomoyuki
T
Tsumuraya
Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.
Masayuki
M
Matsushita
D001120:Arginine / Q000378:metabolism*; D057846:Cell-Penetrating Peptides / Q000378:metabolism*; D020756:Coatomer Protein / Q000378:metabolism*; D004705:Endocytosis; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D015723:Gene Library; D006367:HeLa Cells; D006801:Humans; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D015203:Reproducibility of Results; D027982:Sodium-Bicarbonate Symporters / Q000235:genetics / Q000378:metabolism*; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000378:metabolism
D057846:Cell-Penetrating Peptides; D020756:Coatomer Protein; D034741:RNA, Small Interfering; C498898:SLC4A4 protein, human; D027982:Sodium-Bicarbonate Symporters; D054322:tat Gene Products, Human Immunodeficiency Virus; D001120:Arginine; D016650:Fluorescein-5-isothiocyanate