Human immunodeficiency virus type I (HIV-1) transactivator of transcription (TAT) is encoded by HIV-1. It is a peptide rich in basic amino acids and belongs to the protein transduction domain family. It has been found that HIV-1 TAT and its core peptide segment TAT47-57 play an important role in promoting the cellular uptake of coupled bioactive macromolecules, such as peptides, proteins, oligonucleotides, and drug molecules. HIV-1 TAT can also significantly increase the soluble expression of extrinsic proteins. However, the mechanism behind the cellular uptake of HIV-1 TAT-derived cell-penetrating peptide remains unclear. This review focuses on the research into HIV-1 TAT-derived cell-penetrating peptide over the last years. We briefly discuss TAT's structural features, functions and applications, the mechanism of its cellular internalization, current challenges, and their possible solutions. At the end of this review, we provide a summary and predict the future research directions and potential applications of HIV-1 TAT when it is used as a cell-penetrating peptide.
Keywords: Application; Cell-penetrating peptide; Endocytosis; HIV-1 TAT; Internalization; Mechanism.