Review The odd couple: signal transduction and endocytosis

Cell surface receptors are used to transmit ex- tracellular information. The activation of cell surface re- ceptors initiates signal transduction and receptor endocy- tosis. Signal transduction and the endosomal transport of activated receptors require precise regulation. New con- cepts for the integration of endocytosis and signaling arise from recent findings that suggest bidirectional in-