Receptor signaling signal transfer

Recent publications signal the continued interest in the function of this protein. It has been called a stress enzyme, involved in influenza virus infection (Tomas and Toparceanu, 1986). An explanation for Wilson s disease in terms of a genetic defect resulting in failure to convert from a neonatal (i.e., low) level of ceruloplasmin and copper to a normal adult level has been reported (Srai et al., 1986). Tissue specificity for the binding of ceruloplasmin to membranes was demonstrated in a study investigating the possible role of ceruloplasmin-specific receptors in the transfer of copper from ceruloplasmin to other copper-containing proteins (Orena et al, 1986). Ceruloplasmin has been shown to be effective in transferring copper to Cu,Zn-SOD in culture (Dameron and Harris, 1987), as has copper albumin. In view of the variable content of copper in this protein, it is not clear which copper is transferred. 

Sato M, Kataoka R, Dingus J, Wilcox M, Hildebrandt J, Lanier SM (1995) Factors determining speciUcity of signal transduction by G-protein-coupled receptors. IV. Regulation of signal transfer from receptor to G-protein. J Biol Chem 270 15269-15276... 

Receptors are also located on the presynaptic membrane. These autc-reivptors regulate the release and synthesis of the neurotransmitter and are part of a feedback mechanism that aims to keep the activation or inhibition within the synapse for a discrete time interval and to terminate the signal transfer once the information has reached the adjacent cell via removal (mactivation) of the neurotransmitter from the synaptic cleft. 

Signal transfer through a membrane may occur either by translocation of a species (carrier or channel facilitated) or by transduction via effector/receptor binding (see also Section 8.5.1). 

Fig. 28. Schematic representation of information and signal transfer by transduction across a membrane by means of molecular transmembrane rods (left) two possible in plane configurations with cross sections of the rods (centre) binding of the transmitter and receiver receptors to the rods respectively on the left and on the right of the membrane (right) other non-complementary receptors.

KINETIC ANALYSIS OF G PROTEIN-COUPLED RECEPTOR SIGNALING USING FLUORESCENCE RESONANCE ENERGY TRANSFER IN LIVING CELLS... 

Step 0 The SRP delivers the ribosome/nascent polypeptide complex to the SRP receptor in the ER membrane. This interaction is strengthened by binding of GTP to both the SRP and its receptor. Step Q Transfer of the ribosome/nascent polypeptide to the translocon leads to opening of this translocation channel and insertion of the signal sequence and adjacent segment of the growing polypeptide into the central pore. Both the SRP and SRP receptor, once dissociated from the translocon, hydrolyze their bound GTP and then are ready to... 

Wegener AA, Klare JP, Engelhard M, Steinhoff FU (2001) Structural insights into the early steps of receptor-transducer signal transfer in archaeal phototaxis. EMBO J 20(19) 5312-5319... 

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