Table 1.

Representative CPPs: sequences, applications and major related references

Peptides	Origin	Sequences	Cargo types	References
Peptides deriving from protein transduction domains
Tat	HIV-Tat protein	PGRKKRRQRRPPQ	Protein/peptide/siRNA/liposome/nanoparticle	Snyder and Dowdy (2005); Schwarze et al. (1999)
Penetratin	Homeodomain	RQIKIWFQNRRMKWKK	peptide/siRNA/liposome	Joliot and Prochiantz (2004)
Transportan	Galanin-mastoparan	GWTLNSAGYLLGKINLKALAALAKKIL	Protein/PNA/siRNA	Pooga et al. (1998)
VP-22	HSV-1 structural protein	DAATATRGRSAASRPTERPRAPAR-SASRPRRPVD	Protein	Elliott and O'Hare (1997)
Amphipathic peptides
MPG	HIV Gp41-SV40 NLS	GALFLGFLGAAGSTMGAWSQPKKKRKV	siRNA/ODN/plasmid	Morris et al. (2008)
Pep-1	Trp-rich motif-SV40 NLS	KETWWETWWTEWSQPKKKRKV	Protein/peptide	Gros et al. (2006)
MAP	Chimeric	KALAKALAKALA	Small molecule/plasmid
SAP	Proline-rich motif	VRLPPPVRLPPPVRLPPP	protein/peptide	Pujals et al. (2006)
PPTG1	Chimeric	GLFRALLRLLRSLWRLLLRA	Plasmid	Rittner et al. (2002)
Other cell-penetrating peptides: cationic peptides
Oligoarginine	Chimeric	Agr8 or Arg9	Protein/peptide/siRNA/ODN	Wender et al. (2000); Futaki et al. (2001)
hCT (9–32)	Human calcitonin	LGTYTQDFNKTFPQTAIGVGAP	Protein/plasmid DNA	Schmidt et al. (1998)
SynB	Protegrin	RGGRLSYSRRRFSTSTGR	Doxorubicin	Rousselle et al. (2001)
Pvec	Murine VE-cadherin	LLIILRRRIRKQAHAHSK	Protein/peptide	Elmquist et al. (2001)

CPP, cell-penetrating peptide; NLS, nuclear localization sequence; PNA, peptide-nucleic acid; Tat, transcription-transactivating.