Evidence that microtubules do not mediate opsin vesicle transport in photoreceptors
| Autor: | Brian Matsumoto, Kenneth A. Linberg, Steven K. Fisher, Irene L. Hale, Dana K. Vaughan, S. A. Bernstein |
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| Rok vydání: | 1989 |
| Předmět: |
Fluorescent Antibody Technique
Biology Microtubules Models Biological Cell membrane Xenopus laevis chemistry.chemical_compound Organ Culture Techniques medicine Animals Photoreceptor Cells Cytochalasin Cytoskeleton Fluorescent Dyes Cytochalasin D Cell Membrane Biological membrane Articles Cell Biology Rod Cell Outer Segment Isoquinolines Cell biology Kinetics Microscopy Electron Nocodazole medicine.anatomical_structure Membrane chemistry sense organs Colchicine |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| DOI: | 10.1083/jcb.109.6.3053 |
| Popis: | The organization of the rod photoreceptor cytoskeleton suggests that microtubules (MTs) and F actin are important in outer segment (OS) membrane renewal. We studied the role of the cytoskeleton in this process by first quantifying OS membrane assembly in rods from explanted Xenopus eyecups with a video assay for disc morphogenesis and then determining if the rate of assembly was reduced after drug disassembly of either MTs or F actin. Membrane assembly was quantified by continuously labeling newly forming rod OS membranes with Lucifer Yellow VS (LY) and following the tagged membranes' distal displacement along the OS. LY band displacement displayed a linear increase over 16 h in culture. These cells possessed a longitudinally oriented network of ellipsoid MTs between the sites of OS protein synthesis and OS membrane assembly. Incubation of eyecups in nocodazole, colchicine, vinblastine, or podophyllotoxin disassembled the ellipsoid MTs. Despite their absence, photoreceptors maintained a normal rate of OS assembly. In contrast, photoreceptors displayed a reduced distal displacement of LY-labeled membranes in eyecups treated with cytochalasin D, showing that our technique can detect drug-induced changes in basal rod outer segment assembly. The reduction noted in the cytochalasin-treated cells was due to the abnormal lateral displacement of newly added OS disc membranes that occurs with this drug (Williams, D. S., K. A. Linberg, D. K. Vaughan, R. N. Fariss, and S. K. Fisher. 1988. J. Comp. Neurol. 272:161-176). Together, our results indicate that the vectorial transport of OS membrane constituents through the ellipsoid and their assembly into OS disc membranes are not dependent on elliposid MT integrity. |
| Databáze: | OpenAIRE |
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