Abstract
The fluorescent proteins have expanded various aspects of biological research. Proteins fused to the fluorescent proteins such as green fluorescent protein (GFP) provided researchers an opportunity to visualize the intracellular trafficking of proteins in living cells. The trafficking of proteins including that of steroid receptors involves dynamic interactions with cellular proteins such as heat shock proteins, immunophilins. Such interactions, which can be monitored by GFP fusion proteins, may be altered by pathophysiological conditions and by drugs. Thus, GFP fusion proteins may be applied to the investigations for the pharmacological manipulation of protein trafficking.