engleski

Influence of extracellular p27 on the signal transduction pathways

TAT protein, a basic domain of human immunodeficiency virus type 1 (HIV-1), possess the ability to traverse biological membranes efficiently in a process termed &laquo ; protein transduction&raquo ; . Protein transduction can be described as the direct uptake by the cell of exogenous proteins/peptides, as a result of a specific property of the protein/peptide component. The mechanism is unknown. Transduction occurs in receptor-transporter- independent manner that appears to target the lipid bilayer directly. In the rpesent study, transduction of full-length Tat-p27, pt-mutated Tat-p27 and N'- Tat-p27 (truncated p27 on the C-terminal end) fusion proteins into human tumor cell lines was examined. How these proteins affected on the signal transduction pthways, responsable for proliferation and apoptosis, was also investigated. The proteins (p27, p23, Mp27) were transdused into different cell lines (NALM, MOLT, Raji, SuDHL, K562, RKO and MiaPaCa2) and their effect on proliferation of the cells were measured. The fusion proteins influenced moderately on the proliferation of different cell lines and varied among the proteins and type of the cells. A transduced p27 did not remarkable influence on proliferation of examined cell lines. Mutated p27 inhibited the proliferation of examined cell lines up to 30 %. On the other hand, a transduction of p23 protein, truncated form of p27, inhibited the proliferation all of examined cell lines 30-60 %. Also the effects on expression of host p27 protein were examined, as well as an influence on induction of apoptosis. The expression of cell cycle regulatory proteins (cycD2, D3, cycE) were not remarkable affected with transduced proteins. It seems that transduced proteins induced apoptosis in examined cell lines. According the results, different apoptotic pathways were induced, depending on the type of cells.

p27; apoptosis; cell lines

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