Coupling by Colocalization

The colocalization of signaling proteins at the cell membrane is mediated by 

By bringing together two signaling proteins at the same site of the cell (e.g., in focal adhesion points of the cell membrane) an efficient communication between the pro- 

The colocalization of signaling proteins is essential for the signaling at the cell membrane. The transduction of signals by transmembrane receptors into the interior of the cell occurrs in multiprotein complexes assembled specifically at the inner face of the cell membrane. A large part of the Ras signaling pathway (see Chapter 9) is intimately linked to the cytoplasmic side of the membrane. If membrane association of the components of the Ras signaling pathway is prevented, signal transduction is shut down. 

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