scholarly journals Correlation of rhodopsin biogenesis with ultrastructural morphogenesis in the chick retina.

1975 ◽  
Vol 64 (1) ◽  
pp. 235-241 ◽  
Author(s):  
W T Mason ◽  
K J Bighouse
Keyword(s):  
Outer Segment ◽  
Receptor Cell ◽  
Rod Outer Segments ◽  
Membrane Biogenesis ◽  
Rod Outer Segment ◽  
Rods And Cones ◽  
Outer Segments ◽  
Chick Retina ◽  
Disk Membrane ◽  
Detergent Extraction

The developing chick retina from stages 39-45 has been examined by biochemical and electron microscope techniques. The levels of rhodopsin contained in the maturing chick retina were evaluated by detergent extraction and correlated with rod outer segment formation. It was found that the appearance of rhodopsin in significant levels preceded outer segment formation by at least 2 days, thus implying that rhodopsin is synthesized in the receptor cell inner segment and translocated to the outer limb when disk membrane biogenesis occurs. The level of rhodopsin continues to rise as the rod outer segment develops. Development of both rods and cones originates and proceeds most rapidly in the fundus or central region and proceeds toward the periphery. In general, rod outer segments were noted to develop far more rapidly than cone outer segments.

scholarly journals MEMBRANE CHARACTERISTICS AND OSMOTIC BEHAVIOR OF ISOLATED ROD OUTER SEGMENTS

1973 ◽  
Vol 56 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Juan I. Korenbrot ◽  
Dennis T. Brown ◽  
Richard A. Cone
Keyword(s):  
Plasma Membrane ◽  
Outer Segment ◽  
Receptor Cell ◽  
Water Flux ◽  
Rod Outer Segments ◽  
Repeat Distance ◽  
Permeability Constant ◽  
Outer Segments ◽  
Length Reduction ◽  
Osmotic Behavior

Freshly isolated frog rod outer segments are sensitive osmometers which retain their photosensitivity; their osmotic behavior reveals essentially the same light-sensitive Na+ influx observed electrophysiologically in the intact receptor cell. Using appropriate osmotic conditions we have examined freeze-etch replicas of freshly isolated outer segments to identify the membrane which regulates the flow of water and ions. Under isosmotic conditions we find that the disc to disc repeat distance is almost exactly twice the thickness of a disc. This ratio appears to be the same in a variety of vertebrate rod outer segments and can be reliably measured in freeze-etch images. Under all our osmotic conditions the discs appear nearly collapsed. However, when the length of the outer segment is reduced by hyperosmotic shocks the discs move closer together. This markedly reduces the ratio of repeat distance to disc thickness since disc thickness remains essentially constant. Thus, the length reduction of isolated outer segments after hyperosmotic shocks primarily results from reduction of the extradisc volume. Since the discs are free floating and since they undergo negligibly small changes in volume, the plasma membrane alone must be primarily responsible for regulating the water flux and the light-sensitive Na+ influx in freshly isolated outer segments. On this basis we calculate, from the osmotic behavior, that the plasma membrane of frog rod outer segment has a Na+ permeability constant of about 2.8 x 10-6 cm/s and an osmotic permeability coefficient of greater than 2 x 10-3 cm/s.

scholarly journals Localization of peripherin/rds in the disk membranes of cone and rod photoreceptors: relationship to disk membrane morphogenesis and retinal degeneration.

1992 ◽  
Vol 116 (3) ◽  
pp. 659-667 ◽  
Author(s):  
K Arikawa ◽  
L L Molday ◽  
R S Molday ◽  
D S Williams
Keyword(s):  
Plasma Membrane ◽  
Retinal Degeneration ◽  
Outer Segment ◽  
Photoreceptor Cells ◽  
Growth Stages ◽  
Rod Outer Segments ◽  
Rod Photoreceptor ◽  
Outer Segments ◽  
Disk Membrane ◽  
Membrane Morphogenesis

The outer segments of vertebrate rod photoreceptor cells consist of an ordered stack of membrane disks, which, except for a few nascent disks at the base of the outer segment, is surrounded by a separate plasma membrane. Previous studies indicate that the protein, peripherin or peripherin/rds, is localized along the rim of mature disks of rod outer segments. A mutation in the gene for this protein has been reported to be responsible for retinal degeneration in the rds mouse. In the present study, we have shown by immunogold labeling of rat and ground squirrel retinas that peripherin/rds is present in the disk rims of cone outer segments as well as rod outer segments. Additionally, in the basal regions of rod and cone outer segments, where disk morphogenesis occurs, we have found that the distribution of peripherin/rds is restricted to a region that is adjacent to the cilium. Extension of its distribution from the cilium coincides with the formation of the disk rim. These results support the model of disk membrane morphogenesis that predicts rim formation to be a second stage of growth, after the first stage in which the ciliary plasma membrane evaginates to form open nascent disks. The results also indicate how the proteins of the outer segment plasma membrane and the disk membranes are sorted into their separate domains: different sets of proteins may be incorporated into membrane outgrowths during different growth stages of disk morphogenesis. Finally, the presence of peripherin/rds protein in both cone and rod outer segment disks, together with the phenotype of the rds mouse, which is characterized by the failure of both rod and cone outer segment formation, suggest that the same rds gene is expressed in both types of photoreceptor cells.

scholarly journals Comparison of the phosphodiesterase inhibitory subunit interactions of frog and bovine rod outer segments

1989 ◽  
Vol 259 (1) ◽  
pp. 13-19 ◽  
Author(s):  
M M Whalen ◽  
M W Bitensky
Keyword(s):  
Catalytic Activity ◽  
Binding Sites ◽  
Outer Segment ◽  
Rod Outer Segments ◽  
Rod Outer Segment ◽  
Outer Segments ◽  
Frog Retina ◽  
Inhibitory Site ◽  
Alpha Beta ◽  
Gamma S

The rod outer segments of the bovine and frog retina possess a cyclic GMP phosphodiesterase (PDE) that is composed of two larger subunits, alpha and beta (P alpha beta), which contain the catalytic activity and a smaller gamma (P gamma) subunit which inhibits the catalytic activity. We studied the binding of P gamma to P alpha beta in both the bovine and frog rod outer segment membranes. Analysis of these data indicates that there are two classes of P gamma binding sites per P alpha beta in both species. The activation of PDE by the guanosine 5′-[gamma-thio]triphosphate form of the alpha subunit of transducin, T alpha.GTP gamma S, was also studied. These data indicate that the two classes of P gamma binding sites contribute to the formation of two classes of binding sites for T alpha.GTP gamma S. We demonstrate solubilization of a portion of the P gamma by T alpha.GTP gamma S in both species. There is also present, in both species, a second class of P gamma which is not solubilized even when it is dissociated from its inhibitory site on P alpha beta by T alpha.GTP gamma S. The amount of full PDE activity which results from release of the solubilizable P gamma is about 50% in the frog PDE but only approx. 17% in the bovine PDE. We also show that activation of frog rod outer segment PDE by trypsin treatment releases the PDE from the membranes. This type of release by trypsin has already been demonstrated in bovine rod outer segments [Wensel & Stryer (1986) Proteins: Struct. Funct. Genet. 1, 90-99].

Movement of retinal along cone and rod photoreceptors

1994 ◽  
Vol 11 (2) ◽  
pp. 389-399 ◽  
Author(s):  
Jing Jin ◽  
Gregor J. Jones ◽  
M. Carter Cornwall
Keyword(s):  
Cell Body ◽  
Dark Adaptation ◽  
Visual Pigment ◽  
Outer Segment ◽  
Light Adaptation ◽  
Rod Photoreceptors ◽  
Rod Outer Segment ◽  
Rods And Cones ◽  
Outer Segments ◽  
Rod Cell

AbstractSingle isolated photoreceptors can be taken through a visual cycle of light adaptation by bleaching visual pigment, followed by dark adaptation when supplied with 11–cis retinal. Light adaptation after bleaching is manifested by faster response kinetics and a permanent reduction in sensitivity to light flashes, presumed to be due to the presence of bleached visual pigment. The recovery of flash sensitivity during dark adaptation is assumed to be due to regeneration of visual pigment to pre-bleach levels. In previous work, the outer segments of bleached, light-adapted cells were exposed to 11–cis retinal. In the present work, the cell bodies of bleached photoreceptors were exposed. We report a marked difference between rods and cones. Bleached cones recover sensitivity when their cell bodies are exposed to 11–cis retinal. Bleached rods do not. These results imply that retinal can move freely along the cone photoreceptor, but retinal either is not taken up by the rod cell body or retinal cannot move from the rod cell body to the rod outer segment. The free transfer of retinal along cone but not along rod photoreceptors could explain why, during dark adaptation in the retina, cones have access to a store of 11–cis retinal which is not available to rods. Additional experiments investigated the movement of retinal along bleached rod outer segments. The results indicate that retinal can move along the rod outer segment, but that this movement is slow, occurring at about the same rate as the regeneration of visual pigment.

Proton Uptake by Light Induced Interaction between Rhodopsin and G-Protein

1985 ◽  
Vol 40 (5-6) ◽  
pp. 400-405 ◽  
Author(s):  
Andreas Schleicher ◽  
Klaus Peter Hofmann
Keyword(s):  
G Protein ◽  
Outer Segment ◽  
Bromocresol Purple ◽  
Rod Outer Segments ◽  
Rod Outer Segment ◽  
Outer Segments ◽  
Proton Uptake ◽  
Indicator Dye ◽  
Ph Electrode

Abstract The light-induced proton uptake of rod outer segment disc membranes has been investigated in the absence and presence of G-protein. Proton uptake was measured as the alkalisation of the suspending medium using a pH electrode and/or the indicator dye bromocresol purple. It was found that besides the known proton uptake of photolysed rhodopsin additional uptake of one proton accompanies formation of the complex between rhodopsin and G-protein. No measurable proton uptake was found under conditions of rapid redissociation of the complex indicating an only transient protonation during its lifetime. Proton uptake was the same in washed membra­nes recombined with G-protein and in ordinarily stacked rod outer segments. The additional proton uptake reported here is not due to enhanced metarhodopsin II.

scholarly journals Rhodopsin in the rod outer segment plasma membrane.

1976 ◽  
Vol 69 (1) ◽  
pp. 29-42 ◽  
Author(s):  
S Basinger ◽  
D Bok ◽  
M Hall
Keyword(s):  
Plasma Membrane ◽  
Gel Electrophoresis ◽  
Visual Pigment ◽  
Outer Segment ◽  
Gel Filtration ◽  
Acid Mixture ◽  
Rod Outer Segments ◽  
Gel Filtration Chromatography ◽  
Rod Outer Segment ◽  
Outer Segments

Isolated frog retinas were incubated in vitro with a 4-h pulse of [3H]leucine, then chased for 32 h with a nonradioactive amino acid mixture. At the end of the incubation, light and electron microscope autoradiograms were prepared from some of the retinas. The autoradiograms revealed: (a) intense radioactivity in the basal disks of the rod outer segments, (b) diffuse label evenly distributed throughout the rod outer segments, and (c) a high concentration of label in the entire rod outer segment plasma membrane. Incubation under identical conditions, but with puromycin added, significantly inhibited the labeling of all of these components. To identify the labeled proteins, purified outer segments from the remaining retinas were analyzed biochemically by SDS disc gel electrophoresis and gel filtration chromatography. SDS gel electrophoresis showed that about 90% of the total rod outer segment radioactivity chromatographed coincident with visual pigment, suggesting that the radiolabeled protein in the plasma membrane is visual pigment. Gel filtration chromatography demonstrated that the radiolabeled protein co-chromatographed with rhodopsin rather than opsin, and that the newly synthesized visual pigment is both the basal disks and the plasma membrane is present in the native configuration.

scholarly journals Preparation and characterization of monoclonal antibodies to several frog rod outer segment proteins.

1984 ◽  
Vol 84 (2) ◽  
pp. 251-263 ◽  
Author(s):  
P L Witt ◽  
H E Hamm ◽  
M D Bownds
Keyword(s):  
Monoclonal Antibodies ◽  
G Protein ◽  
Protein Fraction ◽  
Outer Segment ◽  
Solid Phase ◽  
Detection System ◽  
Rod Outer Segments ◽  
Western Blots ◽  
Rod Outer Segment ◽  
Outer Segments

Monoclonal antibodies to proteins important in phototransduction in the frog rod outer segment have been obtained. These include 6 different antibodies to rhodopsin, 50 to a guanine nucleotide binding protein (G-protein; 40,000 daltons), and 2 to cytoplasmic proteins. The antigens used were Percoll-purified rod outer segments, a rod outer segment soluble protein fraction, or a soluble plus peripheral membrane protein fraction. Antibodies were assayed by solid phase assay using a fluorogenic detection system. Proteins to which antibodies bound were assayed on Western blots, and the sensitivities of three different detection systems were compared. Most antibodies bound to only one rod outer segment protein band on Western blots. Immunofluorescence microscopy demonstrated binding of both anti-rhodopsin and anti-G-protein to isolated frog rod outer segments. Antibodies were purified from either culture supernatants or ascites fluid on protein A affinity columns. Two purified anti-G-protein antibodies have binding affinities to 125I-labeled G-protein of less than 10(-6) M-1. Of 11 antibodies to frog or bovine G-protein tested in solid phase and Western blot assays, all bind to the alpha rather than the beta or gamma subunits. Procedures developed here are being used in preparing other antibodies that affect reactions in the phototransduction pathway.

THE STRUCTURE OF RHODOPSIN AND ITS DISPOSITION IN THE ROD OUTER SEGMENT DISK MEMBRANE

1979 ◽  
Vol 29 (4) ◽  
pp. 661-670 ◽  
Author(s):  
E. A. Dratz ◽  
G. P. Miljanich ◽  
P. P. Nemes ◽  
J. E. Gaw ◽  
S. Schwartz
Keyword(s):  
Outer Segment ◽  
Rod Outer Segment ◽  
Disk Membrane

scholarly journals THE RENEWAL OF ROD AND CONE OUTER SEGMENTS IN THE RHESUS MONKEY

1971 ◽  
Vol 49 (2) ◽  
pp. 303-318 ◽  
Author(s):  
Richard W. Young
Keyword(s):  
Rhesus Monkey ◽  
Rhesus Monkeys ◽  
Outer Segment ◽  
Pigment Epithelium ◽  
Renewal Processes ◽  
Visual Cells ◽  
Rods And Cones ◽  
Outer Segments ◽  
Retinal Rod ◽  
Assembly Site

The renewal of retinal rod and cone outer segments has been studied by radioautography in rhesus monkeys examined 2 and 4 days after injection of leucine-3H. The cell outer segment consists of a stack of photosensitive, membranous discs. In both rods and cones some of the newly formed (radioactive) protein became distributed throughout the outer segment. Furthermore, in rods (but not in cones), there was a transverse band of concentrated radioactive protein slightly above the outer segment base 2 days after injection. This was due to the formation of new discs, into which labeled protein had been incorporated. At 4 days, these radioactive discs were located farther from the outer segment base. Repeated assembly of new discs had displaced them away from the basal assembly site and along the outer segment. Measurements of the displacement rate indicated that each retinal rod produces 80–90 discs per day, and that the entire complement of outer segment discs is replaced every 9–13 days. To compensate for the continual formation of new discs, groups of old discs are intermittently shed from the apical end of the cell and phagocytized by the pigment epithelium. Each pigment epithelial cell engulfs and destroys about 2000–4000 rod outer segment discs daily. The similarity between visual cells in the rhesus monkey and those in man suggests that the same renewal processes occur in the human retina.

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