Abstract
Eukaryotic cells use membrane organelles, like the endoplasmic reticulum or the Golgi, to carry out different functions. Vertebrate rod photoreceptors use hundreds of membrane sacs (the disks) for the detection of light. We have used fluorescent tracers and single cell imaging to study the properties of rod photoreceptor disks. Labeling of intact rod photoreceptors with membrane markers and polar tracers revealed communication between intradiskal and extracellular space. Internalized tracers moved along the length of the rod outer segment, indicating communication between the disks as well. This communication involved the exchange of both membrane and aqueous phase and had a time constant in the order of minutes. The communication pathway uses approximately 2% of the available membrane disk area and does not allow the passage of molecules larger than 10 kDa. It was possible to load the intradiskal space with fluorescent Ca(2+) and pH dyes, which reported an intradiskal Ca(2+) concentration in the order of 1 microM and an acidic pH 6.5, both of them significantly different than intracellular and extracellular Ca(2+) concentrations and pH. The results suggest that the rod photoreceptor disks are not discrete, passive sacs but rather comprise an active cellular organelle. The communication between disks may be important for membrane remodeling as well as for providing access to the intradiskal space of the whole outer segment.
Full Text
The Full Text of this article is available as a PDF (315.0 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anderson D. H., Fisher S. K. Disc shedding in rodlike and conelike photoreceptors of tree squirrels. Science. 1975 Mar 14;187(4180):953–955. doi: 10.1126/science.1145180. [DOI] [PubMed] [Google Scholar]
- Apte D. V., Ebrey T. G., Dawson M. J. Decreased energy requirement of toad retina during light adaptation as demonstrated by 31P nuclear magnetic resonance. J Physiol. 1993 May;464:291–306. doi: 10.1113/jphysiol.1993.sp019635. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Basinger S., Hoffman R. Phosphatidyl choline metabolism in the frog rod photoreceptor. Exp Eye Res. 1976 Aug;23(2):117–126. doi: 10.1016/0014-4835(76)90195-0. [DOI] [PubMed] [Google Scholar]
- Besharse J. C., Hollyfield J. G., Rayborn M. E. Turnover of rod photoreceptor outer segments. II. Membrane addition and loss in relationship to light. J Cell Biol. 1977 Nov;75(2 Pt 1):507–527. doi: 10.1083/jcb.75.2.507. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Betz W. J., Mao F., Bewick G. S. Activity-dependent fluorescent staining and destaining of living vertebrate motor nerve terminals. J Neurosci. 1992 Feb;12(2):363–375. doi: 10.1523/JNEUROSCI.12-02-00363.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Betz W. J., Mao F., Smith C. B. Imaging exocytosis and endocytosis. Curr Opin Neurobiol. 1996 Jun;6(3):365–371. doi: 10.1016/s0959-4388(96)80121-8. [DOI] [PubMed] [Google Scholar]
- Bibb C., Young R. W. Renewal of fatty acids in the membranes of visual cell outer segments. J Cell Biol. 1974 May;61(2):327–343. doi: 10.1083/jcb.61.2.327. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bibb C., Young R. W. Renewal of glycerol in the visual cells and pigment epithelium of the frog retina. J Cell Biol. 1974 Aug;62(2):378–389. doi: 10.1083/jcb.62.2.378. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blaurock A. E., Wilkins M. H. Structure of frog photoreceptor membranes. Nature. 1969 Aug 30;223(5209):906–909. doi: 10.1038/223906a0. [DOI] [PubMed] [Google Scholar]
- Boesze-Battaglia K., Lamba O. P., Napoli A. A., Jr, Sinha S., Guo Y. Fusion between retinal rod outer segment membranes and model membranes: a role for photoreceptor peripherin/rds. Biochemistry. 1998 Jun 30;37(26):9477–9487. doi: 10.1021/bi980173p. [DOI] [PubMed] [Google Scholar]
- Boesze-Battaglia K., Yeagle P. L. Rod outer segment disc membranes are capable of fusion. Invest Ophthalmol Vis Sci. 1992 Mar;33(3):484–493. [PubMed] [Google Scholar]
- Cohen A. I. Electron microscope observations on form changes in photoreceptor outer segments and their saccules in response to osmotic stress. J Cell Biol. 1971 Mar;48(3):547–565. doi: 10.1083/jcb.48.3.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen A. I. New evidence supporting the linkage to extracellular space of outer segment saccules of frog cones but not rods. J Cell Biol. 1968 May;37(2):424–444. doi: 10.1083/jcb.37.2.424. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Corless J. M., Costello M. J. Paracrystalline inclusions associated with the disk membranes of frog retinal rod outer segments. Exp Eye Res. 1981 Feb;32(2):217–228. doi: 10.1016/0014-4835(81)90010-5. [DOI] [PubMed] [Google Scholar]
- Dudley P. A., Anderson R. E. Phospholipid transfer protein from bovine retina with high activity towards retinal rod disc membranes. FEBS Lett. 1978 Nov 1;95(1):57–60. doi: 10.1016/0014-5793(78)80051-9. [DOI] [PubMed] [Google Scholar]
- Fain G. L., Schröder W. H. Calcium content and calcium exchange in dark-adapted toad rods. J Physiol. 1985 Nov;368:641–665. doi: 10.1113/jphysiol.1985.sp015881. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fain G. L., Schröder W. H. Light-induced calcium release and re-uptake in toad rods. J Neurosci. 1990 Jul;10(7):2238–2249. doi: 10.1523/JNEUROSCI.10-07-02238.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Flanagan M. T., Hesketh T. R., Chung S. H. Procion yellow M-4RS binding to neuronal membranes. J Histochem Cytochem. 1974 Oct;22(10):952–961. doi: 10.1177/22.10.952. [DOI] [PubMed] [Google Scholar]
- Giusto N. M., Pasquaré S. J., Salvador G. A., Castagnet P. I., Roque M. E., Ilincheta de Boschero M. G. Lipid metabolism in vertebrate retinal rod outer segments. Prog Lipid Res. 2000 Jul;39(4):315–391. doi: 10.1016/s0163-7827(00)00009-6. [DOI] [PubMed] [Google Scholar]
- Gray-Keller M. P., Detwiler P. B. The calcium feedback signal in the phototransduction cascade of vertebrate rods. Neuron. 1994 Oct;13(4):849–861. doi: 10.1016/0896-6273(94)90251-8. [DOI] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- He L., Poblenz A. T., Medrano C. J., Fox D. A. Lead and calcium produce rod photoreceptor cell apoptosis by opening the mitochondrial permeability transition pore. J Biol Chem. 2000 Apr 21;275(16):12175–12184. doi: 10.1074/jbc.275.16.12175. [DOI] [PubMed] [Google Scholar]
- Henkel A. W., Lübke J., Betz W. J. FM1-43 dye ultrastructural localization in and release from frog motor nerve terminals. Proc Natl Acad Sci U S A. 1996 Mar 5;93(5):1918–1923. doi: 10.1073/pnas.93.5.1918. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hollyfield J. G., Rayborn M. E. Endocytosis in the inner segment of rod photoreceptors: analysis of Xenopus laevis retinas using horseradish peroxidase. Exp Eye Res. 1987 Nov;45(5):703–719. doi: 10.1016/s0014-4835(87)80119-7. [DOI] [PubMed] [Google Scholar]
- Kemble G. W., Danieli T., White J. M. Lipid-anchored influenza hemagglutinin promotes hemifusion, not complete fusion. Cell. 1994 Jan 28;76(2):383–391. doi: 10.1016/0092-8674(94)90344-1. [DOI] [PubMed] [Google Scholar]
- Kim J. H., Lingwood C. A., Williams D. B., Furuya W., Manolson M. F., Grinstein S. Dynamic measurement of the pH of the Golgi complex in living cells using retrograde transport of the verotoxin receptor. J Cell Biol. 1996 Sep;134(6):1387–1399. doi: 10.1083/jcb.134.6.1387. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Korenbrot J. I., Brown D. T., Cone R. A. Membrane characteristics and osmotic behavior of isolated rod outer segments. J Cell Biol. 1973 Feb;56(2):389–398. doi: 10.1083/jcb.56.2.389. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Koutalos Y., Brown R. L., Karpen J. W., Yau K. W. Diffusion coefficient of the cyclic GMP analog 8-(fluoresceinyl)thioguanosine 3',5' cyclic monophosphate in the salamander rod outer segment. Biophys J. 1995 Nov;69(5):2163–2167. doi: 10.1016/S0006-3495(95)80090-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Koutalos Y., Nakatani K., Yau K. W. Cyclic GMP diffusion coefficient in rod photoreceptor outer segments. Biophys J. 1995 Jan;68(1):373–382. doi: 10.1016/S0006-3495(95)80198-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kushmerick M. J., Podolsky R. J. Ionic mobility in muscle cells. Science. 1969 Dec 5;166(3910):1297–1298. doi: 10.1126/science.166.3910.1297. [DOI] [PubMed] [Google Scholar]
- Laties A. M., Bok D., Liebman P. Procion yellow: a marker dye for outer segment disc patency and for rod renewal. Exp Eye Res. 1976 Aug;23(2):139–148. doi: 10.1016/0014-4835(76)90197-4. [DOI] [PubMed] [Google Scholar]
- Liebman P. A., Entine G. Lateral diffusion of visual pigment in photorecptor disk membranes. Science. 1974 Aug 2;185(4149):457–459. doi: 10.1126/science.185.4149.457. [DOI] [PubMed] [Google Scholar]
- Llopis J., McCaffery J. M., Miyawaki A., Farquhar M. G., Tsien R. Y. Measurement of cytosolic, mitochondrial, and Golgi pH in single living cells with green fluorescent proteins. Proc Natl Acad Sci U S A. 1998 Jun 9;95(12):6803–6808. doi: 10.1073/pnas.95.12.6803. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Matsumoto B., Besharse J. C. Light and temperature modulated staining of the rod outer segment distal tips with Lucifer yellow. Invest Ophthalmol Vis Sci. 1985 May;26(5):628–635. [PubMed] [Google Scholar]
- NILSSON S. E. THE ULTRASTRUCTURE OF THE RECEPTOR OUTER SEGMENTS IN THE RETINA OF THE LEOPARD FROG (RANA PIPIENS). J Ultrastruct Res. 1965 Feb;12:207–231. doi: 10.1016/s0022-5320(65)80016-8. [DOI] [PubMed] [Google Scholar]
- Nakatani Kei, Chen Chunhe, Koutalos Yiannis. Calcium diffusion coefficient in rod photoreceptor outer segments. Biophys J. 2002 Feb;82(2):728–739. doi: 10.1016/S0006-3495(02)75435-0. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pinton P., Pozzan T., Rizzuto R. The Golgi apparatus is an inositol 1,4,5-trisphosphate-sensitive Ca2+ store, with functional properties distinct from those of the endoplasmic reticulum. EMBO J. 1998 Sep 15;17(18):5298–5308. doi: 10.1093/emboj/17.18.5298. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Poo M., Cone R. A. Lateral diffusion of rhodopsin in the photoreceptor membrane. Nature. 1974 Feb 15;247(5441):438–441. doi: 10.1038/247438a0. [DOI] [PubMed] [Google Scholar]
- Sampath A. P., Matthews H. R., Cornwall M. C., Fain G. L. Bleached pigment produces a maintained decrease in outer segment Ca2+ in salamander rods. J Gen Physiol. 1998 Jan;111(1):53–64. doi: 10.1085/jgp.111.1.53. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scandella C. J., Devaux P., McConnell H. M. Rapid lateral diffusion of phospholipids in rabbit sarcoplasmic reticulum. Proc Natl Acad Sci U S A. 1972 Aug;69(8):2056–2060. doi: 10.1073/pnas.69.8.2056. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schnetkamp P. P. Calcium translocation and storage of isolated intact cattle rod outer segments in darkness. Biochim Biophys Acta. 1979 Jul 5;554(2):441–459. doi: 10.1016/0005-2736(79)90383-3. [DOI] [PubMed] [Google Scholar]
- Thomas J. A., Buchsbaum R. N., Zimniak A., Racker E. Intracellular pH measurements in Ehrlich ascites tumor cells utilizing spectroscopic probes generated in situ. Biochemistry. 1979 May 29;18(11):2210–2218. doi: 10.1021/bi00578a012. [DOI] [PubMed] [Google Scholar]
- Townes-Anderson E., MacLeish P. R., Raviola E. Rod cells dissociated from mature salamander retina: ultrastructure and uptake of horseradish peroxidase. J Cell Biol. 1985 Jan;100(1):175–188. doi: 10.1083/jcb.100.1.175. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wetzel M. G., Besharse J. C. Transport of phosphatidylcholine to Xenopus photoreceptor rod outer segments in the presence of tunicamycin. J Neurocytol. 1994 Jun;23(6):333–342. doi: 10.1007/BF01666523. [DOI] [PubMed] [Google Scholar]
- Winkler B. S. Glycolytic and oxidative metabolism in relation to retinal function. J Gen Physiol. 1981 Jun;77(6):667–692. doi: 10.1085/jgp.77.6.667. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Young R. W. The renewal of photoreceptor cell outer segments. J Cell Biol. 1967 Apr;33(1):61–72. doi: 10.1083/jcb.33.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]