[Diversity of proBDNF and mBDNF functions in the central nervous system]

Brain-derived neurotrophic factor (BDNF) is one of the major protein regulators of diverse biological functions in the nervous system. It is synthesized as a precursor protein (proBDNF) that undergoes proteolytic cleavage in order to become a mature molecule. It was repeatedly shown that the proBDNF/ mBDNF ratio is determined by concomitant neuronal activity. A growing body of evidence argues that proBDNF has its own biological functions, oftentimes in opposition to functions of the mature molecule. Therefore, the balance of concentrations of proBDNF and mature neurotrophin is an important constituent of in any biological processes in nerve cells. Current review is dedicated to key aspects of proBDNF expression, its proteolysis to mBDNF, and its function in developing nervous system, long-term synaptic plasticity, memory consolidation and extinction and possible involvement in pathologies of nervous system.