Functional Reconstitution of Solubilised Receptors

Abstract

Resolution of membrane components and their reconstitution is a classic approach to the analysis of their physiological and biological function. It has been successfully used in many animal systems and more recently its possible application to plants has emerged. In particular, the possible use of reconstitution for plant hormone receptors appears of interest as much progress in this field has been made in the last few years. It is known that receptors are, in general, proteins that specifically recognize a signal (light, hormones) and interact with one or more effector systems. The receptor is activated by the ligand and consequently triggers the effector system. This transduction step may depend on receptor changes such as conformational, chemical modification, microaggregation or internalization and/or by the interaction with transducers such as G proteins, phosphoinositides, protein kinases. For plant hormone receptors only limited evidence is available so far on the mechanisms of their activation and the possible routes of signal transduction. The elements of signal perception and transduction are in a functional membrane complex; therefore their isolation and reconstitution is an important approach to identification of the specific role of each working part of the chain. Before undertaking reconstitution experiments it is first necessary to establish suitable conditions for assay, for solubilisation and for reconstitution with preservation of function. Studies with isolated membranes and with solubilised receptors are therefore important in developing suitable conditions for reconstitution. Some examples will illustrate this approach.