Abstract
Polypeptides in the dorsal root ganglion (L5) of the adult rat were radioactively labeled, and components slowly migrating in the sciatic nerve (peripheral axons) and dorsal root (central axons) were analyzed, using SDS-polyacrylamide slab gel electrophoresis and fluorography. In particular, the transport rates and amounts of six major polypeptides, i.e., the triplet (reference 15; with mol wts of 200,000, 160,000, and 68,000 daltons), alpha- and beta-tubulins and actin were compared between the two axon branches. In peripheral axons, fronts of the triplet, tubulins, and actin migrate at 2-3 mm/d, 9-13 mm/d and approximately 19 mm/d, respectively. The corresponding values in central axons are 1-2 mm/d, 3-4 mm/d, and approximately 4 mm/d, indicating an obvious asymmetry in the transport rate between the two branches of bifurcating axons. A greater amount of labeled triplet, tubulins, and actin each is found to migrate in peripheral than in central axons. Another striking aspect of asymmetry between the two branches relates to the tubulins/triplet ratio which is significantly higher in the peripheral branch. Considerable proportions of radioactivities associated with tubulins and actin in the ganglion are nonmigratory, which are thought to derive mostly from periaxonal satellite cells. In contrast, most if not all of the labeled triplet is migratory, suggesting a virtual absence of triplet polypeptides in satellite cells. The possible significance of peripheral-central inequalities in slow axoplasmic transport is discussed from the viewpoints of axon volume and axonal outgrowth.
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Selected References
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- Abe T., Haga T., Kurokawa M. Rapid transport of phosphatidylcholine occurring simultaneously with protein transport in the frog sciatic nerve. Biochem J. 1973 Nov;136(3):731–740. doi: 10.1042/bj1360731. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bodian D. Development of fine structure of spinal cord in monkey fetuses. II. Pre-reflex period to period of long intersegmental reflexes. J Comp Neurol. 1968 Jun;133(2):113–166. doi: 10.1002/cne.901330202. [DOI] [PubMed] [Google Scholar]
- Bonner W. M., Laskey R. A. A film detection method for tritium-labelled proteins and nucleic acids in polyacrylamide gels. Eur J Biochem. 1974 Jul 1;46(1):83–88. doi: 10.1111/j.1432-1033.1974.tb03599.x. [DOI] [PubMed] [Google Scholar]
- Burgess R. R. Separation and characterization of the subunits of ribonucleic acid polymerase. J Biol Chem. 1969 Nov 25;244(22):6168–6176. [PubMed] [Google Scholar]
- Carmel P. W., Stein B. M. Cell changes in sensory ganglia following proximal and distal nerve section in the monkey. J Comp Neurol. 1969 Feb;135(2):145–166. doi: 10.1002/cne.901350203. [DOI] [PubMed] [Google Scholar]
- Cragg B. G. What is the signal for chromatolysis? Brain Res. 1970 Sep 29;23(1):1–21. doi: 10.1016/0006-8993(70)90345-8. [DOI] [PubMed] [Google Scholar]
- Czéh G., Kudo N., Kuno M. Membrane properties and conduction velocity in sensory neurones following central or peripheral axotomy. J Physiol. 1977 Aug;270(1):165–180. doi: 10.1113/jphysiol.1977.sp011944. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feit H., Slusarek L., Shelanski M. L. Heterogeneity of tubulin subunits. Proc Natl Acad Sci U S A. 1971 Sep;68(9):2028–2031. doi: 10.1073/pnas.68.9.2028. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fine R. E., Bray D. Actin in growing nerve cells. Nat New Biol. 1971 Nov 24;234(47):115–118. doi: 10.1038/newbio234115a0. [DOI] [PubMed] [Google Scholar]
- Friede R. L., Samorajski T. Axon caliber related to neurofilaments and microtubules in sciatic nerve fibers of rats and mice. Anat Rec. 1970 Aug;167(4):379–387. doi: 10.1002/ar.1091670402. [DOI] [PubMed] [Google Scholar]
- Ha H. Axonal bifurcation in the dorsal root ganglion of the cat: a light and electron microscopic study. J Comp Neurol. 1970 Oct;140(2):227–240. doi: 10.1002/cne.901400206. [DOI] [PubMed] [Google Scholar]
- Haga T., Kurokawa M. Microtubule formation from two components separated by gel filtration of a tubulin preparation. Biochim Biophys Acta. 1975 Jun 12;392(2):335–345. doi: 10.1016/0304-4165(75)90015-x. [DOI] [PubMed] [Google Scholar]
- Hoffman P. N., Lasek R. J. The slow component of axonal transport. Identification of major structural polypeptides of the axon and their generality among mammalian neurons. J Cell Biol. 1975 Aug;66(2):351–366. doi: 10.1083/jcb.66.2.351. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KOENIG H. An autoradiographic study of nucleic acid and protein turnover in the mammalian neuraxis. J Biophys Biochem Cytol. 1958 Nov 25;4(6):785–792. doi: 10.1083/jcb.4.6.785. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Komiya Y., Kurokawa M. Asymmetry of protein transport in two branches of bifurcating axons. Brain Res. 1978 Jan 13;139(2):354–358. doi: 10.1016/0006-8993(78)90936-8. [DOI] [PubMed] [Google Scholar]
- Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
- Laskey R. A., Mills A. D. Quantitative film detection of 3H and 14C in polyacrylamide gels by fluorography. Eur J Biochem. 1975 Aug 15;56(2):335–341. doi: 10.1111/j.1432-1033.1975.tb02238.x. [DOI] [PubMed] [Google Scholar]
- Metuzals J., Tasaki I. Subaxolemmal filamentous network in the giant nerve fiber of the squid (Loligo pealei L.) and its possible role in excitability. J Cell Biol. 1978 Aug;78(2):597–621. doi: 10.1083/jcb.78.2.597. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Micko S., Schlaepfer W. W. Protein composition of axons and myelin from rat and human peripheral nerves. J Neurochem. 1978 May;30(5):1041–1049. doi: 10.1111/j.1471-4159.1978.tb12397.x. [DOI] [PubMed] [Google Scholar]
- Peters A., Vaughn J. E. Microtubules and filaments in the axons and astrocytes of early postnatal rat optic nerves. J Cell Biol. 1967 Jan;32(1):113–119. doi: 10.1083/jcb.32.1.113. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schlaepfer W. W., Freeman L. A. Neurofilament proteins of rat peripheral nerve and spinal cord. J Cell Biol. 1978 Sep;78(3):653–662. doi: 10.1083/jcb.78.3.653. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schlaepfer W. W., Micko S. Chemical and structural changes of neurofilaments in transected rat sciatic nerve. J Cell Biol. 1978 Aug;78(2):369–378. doi: 10.1083/jcb.78.2.369. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smith D. E. The location of neurofilaments and microtubules during the postnatal development of Clarke's nucleus in the kitten. Brain Res. 1973 May 30;55(1):41–53. doi: 10.1016/0006-8993(73)90487-3. [DOI] [PubMed] [Google Scholar]
- Wessells N. K., Spooner B. S., Ash J. F., Bradley M. O., Luduena M. A., Taylor E. L., Wrenn J. T., Yamada K. Microfilaments in cellular and developmental processes. Science. 1971 Jan 15;171(3967):135–143. doi: 10.1126/science.171.3967.135. [DOI] [PubMed] [Google Scholar]
- Yamada K. M., Spooner B. S., Wessells N. K. Ultrastructure and function of growth cones and axons of cultured nerve cells. J Cell Biol. 1971 Jun;49(3):614–635. doi: 10.1083/jcb.49.3.614. [DOI] [PMC free article] [PubMed] [Google Scholar]