 |
Previous Article | Next Article 
Journal of Neuroscience, Vol 6, 1593-1605, Copyright © 1986 by Society for Neuroscience
Diversity in the axonal transport of structural proteins: major differences between optic and spinal axons in the rat
IG McQuarrie, ST Brady and RJ Lasek
Investigations of slow axonal transport reveal variation in both protein
composition and the rate of movement. However, these studies involve a
variety of nerve preparations in different species, and most lack the
resolution needed to determine the kinetics of identified proteins. We have
compared the axonal transport of slow-transported proteins in retinal
ganglion cells and spinal motor neurons of young rats. Nine proteins that
contribute to axonal structures were examined: the neurofilament triplet
(NFT), alpha and beta tubulin, actin, fodrin, calmodulin, and clathrin.
Axonally transported proteins were pulse- labeled by intraocular or
intracord injections of 35S-methionine. After allowing sufficient time for
labeled slow-component proteins to enter the spinal or optic nerves,
consecutive 2-3 mm nerve segments were subjected to SDS-PAGE. Fluorographs
were used as templates for locating the gel regions containing the above
polypeptides, and the radioactivity in these regions was measured by
liquid-scintillation spectrometry. In retinal ganglion cells, the peak of
tubulin labeling advanced at 0.36 mm/d in association with the NFT and
fodrin. The cotransport of tubulin and the NFT identified this complex as
the slower subcomponent of slow transport, termed slow component a (SCa)
and representing the movement of the microtubule-neurofilament network. The
peaks of actin and calmodulin labeling were cotransported at 2.3 mm/d in
near-register with peaks of fodrin and clathrin labeling. These 4 proteins,
moving ahead of the NFT, identified this complex as SCb-- the faster
subcomponent of slow transport, which represents the movement of the
cytoplasmic matrix and microtrabecular lattice. Both subcomponents had the
same composition and rate as that reported for the optic axons of guinea
pigs and rabbits, establishing a basic mammalian pattern. In spinal motor
axons, the SCa tubulin peak advanced at 1.3 mm/d, and the SCb actin and
calmodulin peaks were cotransported at 3.1 mm/d. Unlike optic axons, SCa in
motor axons was more heavily labeled than SCb, and included labeled peaks
of actin, clathrin, and calmodulin moving in register with the SCa tubulin
peak. Actin was the most heavily labeled of these SCb proteins moving with
SCa, and it left a higher plateau of radioactivity behind the advancing SCa
peak. The SDS-PAGE labeling pattern for SCb did not differ from that seen
in optic axons, except that some tubulin was found to form a peak that
advanced in register with the actin and calmodulin peaks.(ABSTRACT
TRUNCATED AT 400 WORDS)
This article has been cited by other articles:

|
 |

|
 |
 
J. Bertrand, M. J. Winton, N. Rodriguez-Hernandez, R. B. Campenot, and L. McKerracher
Application of Rho Antagonist to Neuronal Cell Bodies Promotes Neurite Growth in Compartmented Cultures and Regeneration of Retinal Ganglion Cell Axons in the Optic Nerve of Adult Rats
J. Neurosci.,
February 2, 2005;
25(5):
1113 - 1121.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. E. Stokely, S. T. Brady, and T. Yorio
Effects of Endothelin-1 on Components of Anterograde Axonal Transport in Optic Nerve
Invest. Ophthalmol. Vis. Sci.,
October 1, 2002;
43(10):
3223 - 3230.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. M. Herndon
Medical Hypothesis: Why Secondary Progressive Multiple Sclerosis Is a Relentlessly Progressive Illness
Arch Neurol,
February 1, 2002;
59(2):
301 - 304.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. W. Dent, J. L. Callaway, G. Szebenyi, P. W. Baas, and K. Kalil
Reorganization and Movement of Microtubules in Axonal Growth Cones and Developing Interstitial Branches
J. Neurosci.,
October 15, 1999;
19(20):
8894 - 8908.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
F. J. Ahmad, C. J. Echeverri, R. B. Vallee, and P. W. Baas
Cytoplasmic Dynein and Dynactin Are Required for the Transport of Microtubules into the Axon
J. Cell Biol.,
January 26, 1998;
140(2):
391 - 401.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. F. Dillman III, L. P. Dabney, S. Karki, B. M. Paschal, E. L. F. Holzbaur, and K. K. Pfister
Functional Analysis of Dynactin and Cytoplasmic Dynein in Slow Axonal Transport
J. Neurosci.,
November 1, 1996;
16(21):
6742 - 6752.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Q. Jiang and M. M. Oblinger
Differential regulation of beta III and other tubulin genes during peripheral and central neuron development
J. Cell Sci.,
November 1, 1992;
103(3):
643 - 651.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Weisenberg, J Flynn, B. Gao, S Awodi, F Skee, Goodman SR, and B. Riederer
Microtubule gelation-contraction: essential components and relation to slow axonal transport
Science,
November 20, 1987;
238(4830):
1119 - 1122.
[Abstract]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Keith
Slow transport of tubulin in the neurites of differentiated PC12 cells
Science,
January 16, 1987;
235(4786):
337 - 339.
[Abstract]
[PDF]
|
 |
|
|