Signal transduction via G protein coupled receptors: a personal outlook.

Intense research continues to address transmembrane signal transduction. Here we recall seven fundamental concepts governing this field. Only signal transduction via G protein coupled receptors (GPCR), is explicitly considered. But the fundamental concepts apply also to other transmembrane receptors such as receptor protein kinases. Although elements of the signal transduction complexes are readily exchangeable, it appears very likely that these complexes are highly organized in situ; how such organization is achieved remains puzzling, and an important question to be answered. Research in signal transduction can continue to explore with 'reductionist' approaches the fine details of individual molecular properties of signaling proteins and sub-cellular events. Attempts of comprehensive description of the biology of signal transduction cannot--at the present time--take into account the whole complexity of the systems involved. Nevertheless, it appears worthwhile to attempt more wholesome approaches, the results of which might turn out to be quite useful in medicine and pharmacology.