Functional Role of Protein Phosphatase-6 (PPP6c): Regulation of Expression and Modulation of Activity

This review produces information about the role of protein phosphatase-6 (<i>PPP6C</i>) in various biological processes such as cell proliferation, cell cycle regulation, apoptosis, autophagy, cell migration and differentiation, and DNA damage repair. The issues of the participation of <i>PPP6C</i> in the formation of tumor progression and the role of PPP6C in the epigenetic regulation of the tumor process are covered. The article presents in detail the classification of mutations depending on the biological effects they have. It has been shown that various types of mutations in the <i>PPP6C</i> gene can change the composition of the heterotrimeric complex, favoring some regulatory subunits over others, which promotes selective dephosphorylation of substrates to maintain cell viability and change their biological behavior. In particular, their proliferative activity is disrupted, leading to mitosis arrest at various cell cycle stages. An increase in the activity of Aurora A or a decrease in the activity of DNA-dependent protein kinase is considered the main molecular mechanism of tumor development associated with the inactivation of the pp6c protein. The article also discusses the topic of pharmacological modulation of <i>PPP6C</i> activity. PP6 is a protein involved in many biological processes. In this regard, it is especially important to clarify the role of each PP6 holoenzyme and the molecular mechanisms that regulate the formation of the PP6 complex. Changes in the activity of this phosphatase can disrupt cell functioning.