FUNCTIONAL EXPRESSION OF GREEN FLUORESCENT PROTEIN DERIVATIVES IN HALOBACTERIUM-SALINARUM

We investigated the applicability of the green fluorescent protein (GF P) of Aequorea victor ia as a reporter for gene expression in an extre mely halophilic organism: Halobacterium salinarum. Two recombinant GFP s were fused with bacteriorhodopsin, a typical membrane protein of H. salinarum. These fusion proteins preserved the intrinsic functions of each component, bacteriorhodopsin and GFP, were expressed in H. salina rum under conditions with an extremely high salt concentration, and we re proved to be properly localized in its plasma membrane. These resul ts suggest that GFP could be used as a versatile reporter of gene expr ession in H. salinarum for investigations of various halophilic membra ne proteins, such as sensory rhodopsin or phoborhodopsin. (C) 1998 Fed eration of European Microbiological Societies. Published by Elsevier S cience B.V. All rights reserved.