Chemical labeling and freeze-fracture studies on the localization of rhodopsin in the rod outer segment disk membrane

Raubach, Rodger A.; Nemes, Péter; Dratz, Edward A.

doi:10.1016/0014-4835(74)90038-4

Cited by 79 publications

(25 citation statements)

References 25 publications

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“…The DSC results are consistent with similar studies employing Parinaric acid fluorescent probes (Sklar et al, 1979a,b;Sklar & Dratz, 1980), and with 31p NMR studies (Deese, Dratz, & Brown, 1981a;Mollevanger & DeGrip, 1984). The results obtained using DSC are compared to inferences drawn from chemical labeling experiments regarding the transmembrane distribution of the ROS disk membrane phospholipids (Raubach, Nemes & Dratz, 1974b;Smith, Fager & Litman, 1977;Crain, Marinetti & O'Brien, 1978;Drenthe et al, 1980a,b;Miljanich et al, 1981). Additional, useful information regarding the thermal stability (Hubbard, 1958;Cooper & Converse, 1976) of the integral protein components of the ROS disk membranes, viz.…”

Section: Introductionsupporting

confidence: 86%

“…Drenthe et al, 1980a,b), and any broadening or differences in the transition temperature or calorimetric enthalpy of the ROS membranes vis-a-vis the total extracted ROS phospholipids could be due to the presence of rhodopsin, or possibly cholesterol. However, a number of chemical labeling studies suggest the possibility of an asymmetric transbilayer arrangement of the phospholipid head group classes of the ROS disk merebranes (Raubach et al, 1974b;Smith et al, 1977;Crain et al, 1978;Miljanich et al, 1981). If the PC fraction is presupposed to reside largely in one monolayer of the ROS disk membrane, and if the ROS PC fraction gives rise to the observed thermotropic behavior, then one would again expect the transition temperature for the ROS disk membranes to lie between that of the total ROS phosphoJipids and the purified ROS PC fraction--contrary to experimental observation.…”

Section: Ros Membranesmentioning

confidence: 99%

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Thermotropic behavior of retinal rod membranes and dispersions of extracted phospholipids

et al. 1985

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High sensitivity, differential scanning calorimetry studies of bovine retinal rod outer segment (ROS) disk membranes and aqueous dispersions of the extracted ROS phospholipids have been performed. ROS disk membranes were found to exhibit a broad peak of excess heat capacity with a maximum at less than about 3 degrees C, ascribable to a gel-to-liquid crystalline phase transition of a fraction of the phospholipids. A similar thermotropic transition was observed for aqueous dispersions of the total extracted and purified ROS phospholipids. Comparison of the results obtained for the dispersion of total ROS phospholipids to those of the purified head group fractions suggests that the thermotropic behavior reflects a gel-to-liquid crystalline transition, leading to lateral phase separation, involving those phosphatidylcholine (PC) molecules containing saturated fatty acyl chains, possibly together with the highest melting ROS phosphatidylethanolamine (PE) and phosphatidylserine (PS) components. The interpretation of the thermal behavior of the ROS disk membranes depends on whether the transition is assumed to derive from the ROS PC and/or PE/PS fractions, and whether the transbilayer arrangement of the ROS phospholipids is assumed to be symmetric or asymmetric. The calorimetric data can be simply explained in terms of an asymmetric distribution of the major ROS disk membrane phospholipids (G.P. Miljanich et al., J. Membrane Biol. 60:249-255, 1981). In this case, the transition would arise from the PE/PS fractions in the outer ROS disk membrane monolayer, and the anticipated transition from the PC in the inner monolayer would be broadened due to interaction with cholesterol. For the ROS membranes at higher temperatures, two additional, irreversible transitions are observed at 57 and 72 degrees C, corresponding to the thermal denaturation of opsin and rhodopsin, respectively.

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Section: Introductionsupporting

confidence: 86%

Section: Ros Membranesmentioning

confidence: 99%

Thermotropic behavior of retinal rod membranes and dispersions of extracted phospholipids

et al. 1985

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“…There is reasonably strong evidence that PS is located mainly in conjunction with PE in the inner monolayer of erythrocyte membranes (e.g., Rothman and Lenard, 1977;Op den Kamp, 1979). Although there is some controversy about the location of PE and PS in retinal rod outer segment disk membranes (Drenthe et al, 1980), evidence from chemical labeling experiments suggests that these two lipids are preferentially located on the outer or cytoplasmic monolayer of the disks (Raubach et al, 1974;Smith et al, 1977;Crain et al, 1978;Dratz et al, 1979). The adsorption of Ca to PE:PS membranes is, therefore, of some biological interest.…”

Section: Pe'ps Membranesmentioning

confidence: 99%

Adsorption of divalent cations to bilayer membranes containing phosphatidylserine.

McLaughlin¹,

Mulrine²,

Gresalfi³

et al. 1981

The Journal of General Physiology

406

315

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The Stern equation, a combination of the Langmuir adsorption isotherm, the Boltzmann relation, and the Grahame equation from the theory of the diffuse double layer, provides a simple theoretical framework for describing the adsorption of charged molecules to surfaces. The ability of this equation to describe the adsorption of divalent cations to membranes containing brain phosphatidylserine (PS) was tested in the following manner. Charge reversal measurements were first made to determine the intrinsic 1:1 association constants of the divalent cations with the anionic PS molecules: when the net charge of a PS vesicle is zero one-half of the available sites are occupied by divalent cations. The intrinsic association constant, therefore, is equal to the reciprocal of the divalent cation concentration at which the mobility of a PS vesicle reverses sign. The Stern equation with this association constant is capable of accurately describing both the zeta potential data obtained with PS vesicles at other concentrations of the divalent cations and the data obtained with vesicles formed from mixtures of PS and zwitterionic phospholipids. Independent measurements of the number of ions adsorbed to sonicated PS vesicles were made with a calcium-sensitive electrode. The results agreed with the zeta potential results obtained with multilamellar vesicles. When membranes are formed at 20~ in 0.1 M NaCI, the intrinisc 1 : 1 association constants of Ni, Co, Mn, Ba, Sr, Ca, and Mg with PS are 40, 28, 25, 20, 14, 12, respectively.

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“…ROS have been the subject of a number of freeze-fracture analyses carried out primarily to understand the structure of disc membranes (2,13,14,25,41,44,45). Such studies have consistently revealed in oblique fractures, a staircase arrangement of two fracture faces for each disc (Fig.…”

Section: Membranes Of the Outer Segmentmentioning

confidence: 99%

Membrane assembly in retinal photoreceptors I. Freeze-fracture analysis of cytoplasmic vesicles in relationship to disc assembly.

Besharse¹,

Pfenninger²

1980

The Journal of Cell Biology

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To study precursor-product relationships between cytoplasmic membranes of the inner segment of photoreceptors and the continually renewed outer disc membrane, we have compared the density and size distribution of intramembrane particles (IMP) in various membrane compartments of freeze-fractured photoreceptor inner and outer segments . Both rod and cone outer segments of Xenopus laevis are characterized by a relatively uniform distribution of 4,400-4,700 IMP/ IAm2 in P-face (PF) leaflets of disc membranes . A similar distribution of IMP is found in the outer segment plasma membrane, the ciliary plasma membrane, and in the plasma membrane of the inner segment in the immediate periciliary region . In each case the size distribution of IMP can be characterized as unimodal with a mean diameter of -10 nm . PF leaflets of endoplasmic reticulum, Golgi complex, and vesicles near the cilium have IMP with a size distribution like that in the cilium and outer segment, but with an average density of^-2,000/p,m 2 . In contrast, IMP are smaller in average size (^-7 .5 nm) in PF leaflets of inner segment plasma membrane, exclusive of the periciliary region . The similarity of size distribution of IMP in inner segment cytoplasmic membranes and those within the plasmalemma of the cilium and outer segment suggest a precursor-product relationship between the two systems. The structure of the vesicle-rich periciliary region and the segregation of IMP with different size distributions in this region suggest that components destined for incorporation into the outer segment exist as preformed membrane packages (vesicles) which fuse with the inner segment plasma membrane in the periciliary region . Subsequently, membrane components may be transferred to forming discs of the outer segment via the ciliary plasma membrane .Vertebrate photoreceptors are composed of a photosensitive outer segment (ROS), an inner segment that contains the cell's metabolic machinery (i .e ., endoplasmic reticulum, Golgi complex, ribosomes, mitochondria), and a synaptic terminal at which contacts with second-order neurons of the retina are made . The photosensitive outer segment (Fig . 1) is connected to the inner segment by a modified, nonmotile cilium (42), and consists of a series of discrete membranous discs that are apparently derived from the plasma membrane in the region of the connecting cilium (32) . The process of disc assembly, which continues throughout the life of the cell (49, 50), is widely believed to involve infolding of ROS plasma membrane (32) or protrusion of ciliary plasma membrane (1) . Either

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Chemical labeling and freeze-fracture studies on the localization of rhodopsin in the rod outer segment disk membrane

Cited by 79 publications

References 25 publications

Thermotropic behavior of retinal rod membranes and dispersions of extracted phospholipids

Thermotropic behavior of retinal rod membranes and dispersions of extracted phospholipids

Adsorption of divalent cations to bilayer membranes containing phosphatidylserine.

Membrane assembly in retinal photoreceptors I. Freeze-fracture analysis of cytoplasmic vesicles in relationship to disc assembly.

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