|[Frontiers in Bioscience 1, d19-29 March 1, 1996]|
MICROINJECTION STRATEGIES FOR THE STUDY OF MITOGENIC SIGNALING
IN MAMMALIAN CELLS
Ned J.C.Lamb, Cecile Gauthier-Rouviere and Anne Fernandez.
Cell Biology Unit, C R B M , CNRS-INSERM, 1919, Route de Mende, F-34033, Montpellier Cedex. France.
Received 15/12/95; Accepted 30/01/96; On-line 03/01/96
As a whole, microinjection provides a powerful and unique tool to analyze the processes involved in cell activation and growth. Carefully controlled, it can be used to specifically interfere with transcriptional activation, post-transitional modification or the expression of particular proteins. In many cases, microinjection of specific inhibitors or activators facilitates the study of short term cellular events in a temporally controlled manner. Cellular processes can be shut-down, inhibited, prevented, activated or competed, in a direct way at precise and chosen moments. Through microinjection of different solutions on the same dish or coverslip, many potential artifacts can be controlled for in a single experiment, providing that a statistically valid number of cells can be injected with facility.
As the nature and complexity of cellular regulation grows continuously, the capacity to directly manipulate given targeted processes becomes more important. In allowing targeted manipulation of cell environment in the context of the living cell, microinjection provides a unique window on cellular events. Only by directly manipulating single cellular components, will it become possible to identify subtle nuances in the inter-relation between different proteins and cellular pathways. With the rapid advance of the identification of gene sequences encoding all human proteins, we will soon be at the point where many structural motifs, post-transitional modifications and protein interaction sites will also be identified. By allowing the direct manipulation of cellular processes, protein expression, activity and cytolocalization, microinjection should play an integral role in the dissection of the events involved in mitogenic activation. The uses we have described in this review represent some of the initial learning steps that will pave the way to unveil the intricate processes involved in mitogenesis.