Identification of G protein-coupled receptors in insect cells.

Abstract

Communication processes lay at the very basis of physiological functioning and therefore, probably at the true basis of Life itself (as outlined by De Loof and Vanden Broeck1). All communication systems, including modern forms of human communication as well as biological communication systems, are based on similar fundamental principles or requirements and typically consist of the following three main parts: (1) the environment or a “sender-encoder” system which produces a signal or a message that is transmitted via a (2) “communication channel” towards a (3) “receiver-decoder-amplifier-responder.”2 In biological systems, physiological responses to extracellular signals and messages are generated by a process called signal transduction which is elicited by activation of specific receptor proteins. Interestingly, the four main classes of signaltransducing receptor proteins (ligand-gated ion channels, single-transmembrane proteins, seven-transmembrane G protein–coupled receptors [GPCRs], and nuclear receptors) are present in all metazoans.3 This review deals with the different kinds of GPCRs already identified in insect cells.