title: Modulation of nuclear internalization of Tat peptides by fluorescent dyes and receptor-avid peptides.
abstract: The nuclear internalization of biomolecules by Tat peptide provides a mechanism to deliver drugs to cells. However, translocation of molecular imaging probes to the nucleus may induce undesirable mutagenesis. To assess the feasibility of retaining its cell permeating effect without nuclear translocation, Tat-peptide was conjugated with a somatostatin receptor (STR)-avid ligand (Oct) and labeled with fluorescent dyes. The results show that Tat-Oct-5-FAM (fluorescein 5'-carboxylic acid) remained in the cytoplasm of STR-positive AR42J cells. Co-incubation of Tat-Oct-5-FAM with ATP induced nuclear translocation. These data suggest that both dye and Oct-STR endocytosis complex could modulate nuclear internalization of Tat peptides.
authors.affiliation: Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, United States.
authors.forename: Duanwen
authors.initials: D
authors.lastname: Shen
authors.forename: Kexian
authors.initials: K
authors.lastname: Liang
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Ye
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tetteh
authors.forename: Samuel
authors.initials: S
authors.lastname: Achilefu
mesh_terms: D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D000818:Animals; D002232:Carbocyanines / Q000138:chemical synthesis / Q000493:pharmacokinetics; D002467:Cell Nucleus / Q000378:metabolism*; D004705:Endocytosis; D005456:Fluorescent Dyes / Q000493:pharmacokinetics*; D015696:Gene Products, tat / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics*; D006801:Humans; D008954:Models, Biological; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000493:pharmacokinetics*; D051381:Rats; D017481:Receptors, Somatostatin / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014966:Xanthenes / Q000138:chemical synthesis / Q000493:pharmacokinetics; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D002232:Carbocyanines; D005456:Fluorescent Dyes; D015696:Gene Products, tat; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D017481:Receptors, Somatostatin; C520543:Tat-octreotate-Cypate2; C520544:Tat-octreotate-fluorescein 5'-carboxylic acid; D014966:Xanthenes; D054322:tat Gene Products, Human Immunodeficiency Virus; C520542:tat peptide (48-57), Human immunodeficiency virus 1