Highly efficient cellular uptake of a cell-penetrating peptide (CPP) derived from the capsid protein of porcine circovirus type 2.
J Biol Chem
; 293(39): 15221-15232, 2018 09 28.
Article
em En
| MEDLINE
| ID: mdl-30108178
ABSTRACT
Porcine circovirus type 2 (PCV2) is one of the smallest, nonenveloped, single-stranded DNA viruses. The PCV2 capsid protein (Cap) is the sole viral structural protein and main antigenic determinant. Previous sequence analysis has revealed that the N terminus of the PCV2 Cap contains a nuclear localization signal (NLS) enriched in positively charged residues. Here, we report that PCV2's NLS can function as a cell-penetrating peptide (CPP). We observed that this NLS can carry macromolecules, e.g. enhanced GFP (EGFP), into cells when they are fused to the NLS, indicating that it can function as a CPP, similar to the classical CPP derived from HIV type 1 transactivator of transcription protein (HIV TAT). We also found that the first 17 residues of the NLS (NLS-A) have a key role in cellular uptake. In addition to entering cells via multiple endocytic processes, NLS-A was also rapidly internalized via direct translocation enabled by increased membrane permeability and was evenly distributed throughout cells when its concentration in cell cultures was ≥10 µm Of note, cellular NLS-A uptake was â¼10 times more efficient than that of HIV TAT. We inferred that the externalized NLS of the PCV2 Cap may accumulate to a high concentration (≥10 µm) at a local membrane area, increasing membrane permeability to facilitate viral entry into the cell to release its genome into a viral DNA reproduction center. We conclude that NLS-A has potential as a versatile vehicle for shuttling foreign molecules into cells, including pharmaceuticals for therapeutic interventions.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sinais de Localização Nuclear
/
Proteínas do Capsídeo
/
Produtos do Gene rev do Vírus da Imunodeficiência Humana
/
Peptídeos Penetradores de Células
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article