The origin and evolution of terpenoid messengers

Abstract

Within organisms, terpenoids are known for their physiological activities on cell level. They can influence cell stage and mitosis, resulting in changes in morphology and differentiation. Terpenoid endproducts and certain precursors of the mevalonate metabolism and other exogenous terpenoids can affect the synthesis of endproducts and intermediates of other branches or interfere with gene expression, or more directly, act as enzyme or key enzyme regulators. The preciseness with which the enzymes of the various steps of the biosynthesis of terpenoid endproducts operate and the effective feedback systems acting on enzymes and key enzymes are the result of a long evolutionary process. Between organisms, functions of specific terpenoids as messengers are likewise the outcome of a long process of selection of adequate production and reception. This chapter covers the basic regulatory processes involved in the biosynthesis of isoprene units in plants, insects and vertebrates. As in many biochemical processes, overproduction of endproducts is in some way prevented. Once produced in an efficient way, the same terpenoid can acquire a number of messenger functions in completely different organisms. Chapter 3 will discuss the development of regulatory mechanisms during evolution, whereas chapter 4 focusses on the relationship between chemical and physical characteristics of terpenoids and their effects on the receptor sites.