[Influence of prothymosin alpha and its mutants on activity of the p53 tumor suppressor].

Overexpression of the nuclear oncoprotein prothymosin a enhanced and, in a reciprocal experiment, down-regulation of endogenous prothymosin alpha by RNA interference approach inhibited transcriptional activity of the p53 tumor suppressor in the reporter gene assay. Ectopic expression of prothymosin alpha enhanced not only p53-dependent transcription, but also intracellular level of p53 in HeLa (but not HCT116) cells. Ability to stimulate p53-dependent transcription was lost by C-terminal mutants of prothymosin alpha with impaired nuclear accumulation, but not by N-terminal deletion mutants and by the double mutant of prothymosin alpha with impaired ability to bind Keap1, suggesting that prothymosinalpha-Keap1 interaction is dispensable for p53 response.

[Prothyomosin alpha interaction with KEAP1 doesn't lead to prothymosin alpha ubiquination and degradation].

Prothymosin alpha (ProTalpha) is a highly conserved protein in vertebrates that possesses a number of biological functions. One of these functions of ProTalpha is the ability to enhance antioxidant defence system of a cell via its interaction with Keap1 protein. Keap1 is a repressor of Nrf2, a transcription factor responsible for activation of genes that code for defensive proteins.

[Novel functions of the well-known protein--prothymosin alpha is involved in protection of cells against apoptosis and oxidative stress].

Several novel functions of the well-known and intensively studied protein prothymosin alpha have recently been revealed. In addition to such traditional functions of this protein as immunomodulatory activity and stimulation of cellular proliferation, prothymosin alpha was shown to be involved in protection of cells against apoptosis and in regulation of expression of the oxidative stress-protective genes. Methods and approaches used for revelation of prothymosin alpha novel functions are described in this review.