Seven-transmembrane segment receptors

Dohlman, H. G., Thorner, J., Caron, M. G., and Lefkowitz, R. J. (1991) Model systems for the study of seven-transmembrane-segment receptors. Annu. Rev. Biochem. 60, 653-688. 

Figure 6.3. G Protein-coupled receptor retrieved from GPCRDB.Seven transmembrane segment receptor for serotonin retrieved from GPCRDB is visualized in a snake-like plot. The colored groups of residues show a correlated behavior as determined by correlated mutation analysis (CMA). The colored positions are hyperlinked to their corresponding residue locations in the multiple sequence alignments.

Farzan, M., Choe, H Martin, K Marcon, L., Hofmann, W Karlsson, G., et al. (1997) Two orphan seven-transmembrane segment receptors which are expressed in CD4-positive cells support simian immunodeficiency virus infection.. /. Exp. Med. 186,405 411. 

Gerard, G., and Gerard, N. P. (1994). G5A anaphylatoxin and its seven transmembrane-segment receptor. Annu. Rev. Immunol. 12, 775-808. 

Several human receptors for the neurohypophyseal hormones have been cloned and the sequences elucidated. The human V2 receptor for antidiuretic hormone presumably contains 371 amino acids and seven transmembrane segments and activates cycHc AMP (76). The oxytocin receptor is a classic G-protein-coupled type of receptor with a proposed membrane topography also involving seven transmembrane components (84). A schematic representation of the oxytocin receptor stmcture within the membrane is shown in Eigure 4 (85). 

Several nonconventional cadherins that contain cadherin repeats have been described but they have specific features not found in the classical cadherins [1]. The cadherin Flamingo, originally detected in Drosophila, contains seven transmembrane segments and in this respect resembles G protein-coupled receptors. The extracellular domain of Flamingo and its mammalian homologs is composed of cadherin repeats as well as EGF-like and laminin motifs. The seven transmembrane span cadherins have a role in homotypic cell interactions and in the establishment of cell polarity. The FAT-related cadherins are characterized by a large number of cadherin repeats (34 in FAT and 27 in dachsous). Their cytoplasmic domains can bind to catenins. T- (=truncated-)cadherin differs from other cadherins in that it has no transmembrane domain but is attached to the cell membrane via a glycosylpho-sphatidylinositol anchor. 

G-Protein-Coupled Receptors Comprise a Very Large Superfamily of Proteins with Seven Transmembrane Segments... 

A membrane receptor that is functional, linked to the activation of a trimeric G protein complex characterized by the presence of seven transmembrane segments. 

Hydropathy plot. The hydropathic index is plotted on they axis, with hydrophobic domains at the top and hydrophilic domains at the bottom. The x axis shows the amino-acid residue number from the amino to the carboxy terminus. The protein shown is a 7-transmembrane receptor (the serotonin receptor), analogous to the epinephrine (adrenalin) receptor. The approximate positions of the seven transmembrane segments are indicated by the purple bars. (Original plot graciously provided by... 

Particularly common are the iV myristoyl- and S-palmitoyl anchoring motifs shown here. AAmyristoylation al ys occurs at an iV-terminal glycine residue, whereas thioester linkages occur at cysteine residues within the polypeptide chain. G-protein—coupled receptors, with seven transmembrane segments, may contain one (and sometimes two) palmitoyl anchors in thioester linkage to cysteine residues in the C-terminal segment of the protein. 

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