The main focus of the research in the laboratory is currently split into two major directions which are apparently distinct from each other with respect to the biological systems involved, their relation to the human disease, and experimental models used. However, the main idea underlying both directions is conceptually the same - to understand how endocytosis and post-endocytic trafficking regulates function(s) of the transmembrane proteins, such as receptors and transporters. In particular, we aim at elucidating the molecular mechanisms of endocytosis of growth factor receptors using a prototypic member of the family, epidermal growth factor (EGF) receptor, and analysis of the role of endocytosis in spatial and temporal regulation of signal transduction by the EGF receptor. In the second direction, we would like to elucidate the role of trafficking processes in the regulation of dopaminergic neurotransmission by the plasma membrane dopamine transporter (DAT). By understanding how DAT activity is regulated, we will better appre­ci­ate its contribution to normal neurotransmission and to brain diseases like drug addic­tion.