Receptors dual-function

A second difference between the antibody and the TCR is that the antibody can be produced in two forms, secreted or membrane-bound, whereas the TCR is always membrane-bound. The secreted antibody has a dual function where the V domains bind antigens and the C domain binds to the Fc receptors. 

Since ACTH receptors stimulate adenylyl cyclase via Gs, the simplest explanation for the above data is that Gs may have the dual function of stimulating adenylyl cyclase and, albeit transiently, plasma membrane Ca2+ channels. 

Another endogenous peptide which has been implicated in pain transmission and the central integration of pain responses is neurotensin (NeT) (Dobner, 2006 Gui et al., 2004 Pettibone et al., 2002). NeT is a brain-gut tridecapeptide that fulfils a dual function as a neurotransmitter/neuromodulator in the nervous system, and as a paracrine and circulating hormone at the periphery. Three NeT receptors, NTRl,... 

It is believed that the insulin receptor kinase might activate other serine-specific kinases which have a dual function, i.e. further transduction of the... 

Michelson, A.M., Gisselbrecht, S., Zhou, Y., Back, K.H., and Buff, E.M. (1998b). Dual functions of the heartless fibroblast growth factor receptor in development of the Drosophila embryonic mesoderm. Dev. Genet. 22 212-229. 

Fig. 11.17 The dual function of pseudoprolines is demonstrated for the example of proline-rich peptides as ligands for Src homology domains (SH3). Wro building blocks induce the relevant PPM conformation of the ligand and allow in addition the modulation of affinity and specificity by tuning van der Waals contacts and hydrogen bonding interactions of the substituents Rat C2 of YPro to the receptor molecule [195].

Initiates cotranslational translocation of the protein through the combined action of the SRP and SRP receptor. Once the N-terminus of the growing polypeptide enters the lumen of the ER, the signal sequence is cleaved, and the growing chain continues to be extruded across the ER membrane. However, unlike the case with secretory proteins, a sequence of about 22 hydrophobic amino acids in the middle of a type I protein stops transfer of the nascent chain through the translo-con (Figure 16-11). This Internal sequence, because of Its hydrophobicity, can move laterally between the protein subunits that form the wall of the translocon and become anchored in the phospholipid bilayer of the membrane, where It remains. Because of its dual function, this sequence Is called a stop-transfer anchor sequence. 

Ardini, E., Pesole, G., Tagliabue, E., Magnifico, A., Castronovo, V., Sobel, M.E., Colnaghi, M.I., and Menard, S. (1998). The 67-kDa laminin receptor originated from a ribosomal protein that acquired a dual function during evolution. Md. Bid. Evd. 15, 1017-1025. 

A. Cambi, C.G. Figdor, Dual function of C-type lectin-like receptors in the immune system, Curr. Opin. Cell Biol. 2003, 15, 539-546. 

Moniri NH, Covington-Strachan D, Booth RG. Ligand-directed functional heterogeneity of histamine Hi receptors novel dual-function ligands selectively activate and block Hi-mediated phospholipase C and adenylyl cyclase signaling. J Pharmacol Exp Ther 2004 311 274-281. 

In bacteria like E. coli and Salmonella, some chemotactic stimuli bind directly to chemotaxis-specific receptors, whereas others bind first to a primary receptor, which then interacts with a chemotaxis-specific receptor (Figure 12). The chemotaxis-specific receptors are the MCPs, mentioned in Section 5. The primary receptors are dual function in the sense that they are involved in both chemotaxis and transport of the stimulants. 

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