¹Division of Biology 147-75, California Institute of Technology, Pasadena, California 91125, USA

²Institut für Pharmakologie, Freie Universität Berlin, Thielallee 69-73, 14195 Berlin, Germany

^aAuthor for correspondence

Heterotrimeric G-proteins are important signalling proteins which function in all cells of the mammalian organism. Inactivating mutations in a variety of G-protein -subunit genes in mice resulted in mostly unexpected phenotypes and have provided interesting new insight into their biological roles. Whereas the inactivation of some G genes led to mild phenotypes suggesting the presence of redundant or compensatory mechanisms, other G-proteins appear to play highly specific biological or developmental roles. The purpose of this review is to summarize the current knowledge about G-protein functions based on gene-inactivation studies.

G-protein; gene targeting; transgenic mouse; transmembrane signalling