The opsin family of proteins

Findlay, John B. C.; Pappin, Darryl

doi:10.1042/bj2380625

Cited by 249 publications

(107 citation statements)

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“…from hydropathicity analysis of the primary sequences and comparison with the opsin family of proteins, has been supported by studies utilising cleavage with proteolytic enzymes [6] or immunological mapping [13 -151. Experiments utilising a variety of techniques including photolabelled analogues of the endogenous ligands, mutations of the binding proteins and modelling analysis have suggested that the ligand-binding site for aminergic neurotransmitters resides within the hydrophobic core of the protein, intercalated among the transmembrane helices [l-7, 16, 171.…”

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confidence: 99%

Three‐Dimensional Structure of the Highly Conserved Seventh Transmembrane Domain of G‐Protein‐Coupled Receptors

Berlose

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Brunissen

et al. 1994

European Journal of Biochemistry

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The S/T-XI-X,-N-P-X,-X,-Y highly conserved sequence of the seventh transmembrane (TM VII) segment of G-protein-coupled receptors is not present in the photon receptor bacteriorhodopsin TM VII domain. Despite this noticeable discrepancy in sequence, the X-ray structure of bacteriorhodopsin is generally used as the key structure for modelling all G-protein-coupled receptors. Thus, a kinked truns-Pro helix is usually accepted for the TM VII three-dimensional structure of G-proteincoupled receptors, although Asn-Pro dipeptide mainly induces a type UIII /3-turn conformation in both model peptides and proteins. NMR studies in various solvents and molecular calculations were undertaken in order to gain insight into the conformational behaviour of a 15-residue peptide from the tachykinin NK-1 TM VII domain incorporating this common sequence. The low solubility of this membrane-embedded peptide precludes methanol or micellar systems mimicking membrane environment; thus only dimethylsulfoxide (Me,SO) or chlorofonn/Me,SO mixture could be used. We also found that perfluoro-tert-butanol, which has not been previously used for NMR studies, constitutes an excellent alternative solvent for the analysis of hydrophobic peptides. The postulated kinked truns-Pro helix was only present as a minor conformer in Me,SO and an equilibrium between helical and extended structures existed. From NOE data a type I/III ,&structure, centered around Pro9-Ile10, probably stabilized by an Asx turn, may be postulated. Addition of chloroform in Me,SO increased the percentage of folded structures but no preferential conformation could be proposed. In perfluoro-tert-butanoI/CD,OD (9 : 1) the N-and C-terminal regions presented an a-helical structure, and these two domains were linked by a hinge around Asn-Pro with a y-turn for the preceding residue Tyr7 and either a type I/III p-turn around Pro9-IlelO or cxR orientations for these residues, which are both stabilized by an Asx turn. As determined by energy calculations, these structures were equally as stable as the kinked truns-Pro helix and could constitute key structures for analysing the conformational changes and/or the dynamics of TM VII segment induced by the ligand when interacting with the receptor.The apparent similarity in the hydropathicity profiles of G-protein-coupled receptors [ 1 -41 with that of bacteriorhodopsin [5] has led to the use of this integral membrane protein as a starting point for predicting their three-dimensional structures [6-121, even though bacteriorhodopsin is not coupled to G-proteins. The currently accepted proposal for the topography of G-protein-coupled receptors includes seven transmembrane-spanning domains (TM I-VII) joined together by extracellular and cytoplasmic loops, with the Nterminal side in the extracellular cleft and the C-terminal residues in the cytoplasm. This model, which was first deduced Correspondence to S .

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confidence: 99%

Three‐Dimensional Structure of the Highly Conserved Seventh Transmembrane Domain of G‐Protein‐Coupled Receptors

Berlose

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Brunissen

et al. 1994

European Journal of Biochemistry

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“…[29][30][31] A counterion, negatively charged amino acid residue, stabilizes the protonated Schiff base and is essential for visible light absorption by opsin-based pigments (Figure 2). Mutational analyses using varied opsin-based pigments have revealed that the position of the counterion is different between bleaching and bistable pigments.…”

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confidence: 99%

Evolution and diversity of opsins

Terakita

Kawano‐Yamashita

Koyanagi

2011

WIREs Membr Transp Signal

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Many animals capture light information via opsin-based pigments. Several thousands of opsins have been identified thus far and the opsin family is divided into eight groups. Members belonging to four out of the eight groups have been elucidated to couple to transducin, Go, Gs, and Gq, respectively, in photoreceptor cells. Accumulated evidence suggests a novel classification of the animal phototransductions, cyclic nucleotide signaling mediated by transducin, Go or Gs in ciliary photoreceptor cells and phosphoinositol signaling mediated by Gq in rhabdomeric photoreceptor cells. Varied opsin-based pigments are spectroscopically classified into two types, bleaching and bistable pigments; that is, the photoproduct of vertebrate visual pigments dissociates its chromophore retinal over time and bleaches, whereas most other opsin-based pigments convert to a stable photoproduct, which can revert to original dark state by subsequent light absorption. Mutational analyses of the both types of pigments implied that during molecular evolution of the vertebrae visual pigments, displacement of the counterion, important amino acid residue for visible light absorption of opsin-based pigment, resulted in not only unique bleaching property but also acquisition of red-sensitive visual pigment and higher G-protein activation ability generated by larger light-induced conformational change of the pigment. Interestingly, a bleaching pigment rhodopsin and parapinopsin, which closely relates to the vertebrate visual pigment but has a bistable nature, couple to visual arrestin and β arrestin, respectively, in the lamprey pineal organ, suggesting the bleaching property also might facilitate the evolution of visual arrestin which is specialized for vertebrate visual function. 

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“…The photoreceptor pigment, rhodopsin, is the best characterized of the receptor proteins (Findlay & Pappin, 1986) and has become the model for others. Biophysical measurements of rhodopsin (Chabre, 1985) and the deduced amino acid sequences of other receptors are consistent with the structure shown in Fig.…”

Section: Structure and Function In G Protein Signalling Pathwaysmentioning

confidence: 99%

“…While these approaches may eventually answer the most fundamental question in pharmacology, the nature of receptor activation, we do not have the answer yet. The structures and functions of this family of G protein-linked receptors are described in greater detail in many recent reviews (Findlay & Pappin, 1986;Dohlman et al, 1987;Chabre & Deterre, 1989;Ross, 1989;Strader et al, 1989;O'Dowd et al, 1989). In contrast to receptors and G proteins, the effectors they regulate appear to have little in common.…”

Section: Structure and Function In G Protein Signalling Pathwaysmentioning

confidence: 99%

“…The membranes of vertebrate retinal discs, enriched in highly unsaturated lipids and deficient in cholesterol, are unusually fluid (Findlay & Pappin, 1986). Indeed, rhodopsin is among the most mobile of integral membrane proteins with a diffusion coefficient some 10 times greater than the integral proteins of most membranes (Poo & Cone, 1974 (Foster, 1980;Saibil & Hewat, 1987).…”

Section: Sensitivity Of Receptorsmentioning

confidence: 99%

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The role of G proteins in transmembrane signalling

Taylor

1990

Biochemical Journal

226

113

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INTRODUCTIONIn some transmembrane signalling systems detection of the extracellular stimulus and generation of an intracellular response are properties of the same protein or protein complex. Binding of acetylcholine to the a subunits of the pentameric nicotinic receptor, for example, opens a cation-selective channel formed by parts of each of the receptor subunits, and insulin when it binds to the extracellular domain of its receptor activates a protein tyrosine kinase activity in the intracellular domain of the same protein. Rodbell and his collaborators (Rodbell et al., 1971) were the first to provide evidence for a more complex class of signalling pathway where the sensor and intracellular effector are separate proteins that communicate through a guanine nucleotide-dependent regulatory protein or G protein. The G protein cycles between inactive GDP-bound and active GTPbound forms. Activation is catalysed by receptors and deactivation is an intrinsic property of the G protein, its GTPase activity. The developments that followed Rodbell's pioneering studies have established that many different receptors regulate many intracellular effectors through a family of closely related G proteins (Citri & Schramm, 1980;Rodbell, 1980;Schramm & Selinger, 1984;Northup, 1985;Levitzki, 1988). Many excellent recent reviews have focused on various aspects of these interactions between receptors, G proteins and intracellular effectors (Casperson & Bourne, 1987;Gilman, 1987;Allende, 1988;Lochrie & Simon, 1988;Weiss et al., 1988;Chabre & Deterre, 1989;Ross, 1989;Houslay, 1990).The G protein cycle, at the centre of the conversation between receptors and their effectors, provides one solution to the compromise that cells must make between responding rapidly and being able to respond to very low concentrations of extracellular stimulus. In this review I will consider how different signalling mechanisms are adapted to the cellular processes they control by comparing the properties of the signalling pathways that involve G proteins with the simpler pathways that do not.

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The opsin family of proteins

Cited by 249 publications

References 274 publications

Three‐Dimensional Structure of the Highly Conserved Seventh Transmembrane Domain of G‐Protein‐Coupled Receptors

Three‐Dimensional Structure of the Highly Conserved Seventh Transmembrane Domain of G‐Protein‐Coupled Receptors

Evolution and diversity of opsins

The role of G proteins in transmembrane signalling

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