Journal of Neuroscience, Vol 9, 574-581, Copyright © 1989 by Society for Neuroscience
Relationship between phosphorylation and synthesis of goldfish optic nerve proteins during regeneration
DC Larrivee and B Grafstein
Department of Physiology, Cornell University Medical College, New York, New York 10021.
After intraocular injection of radiolabeled phosphate and 3H-proline, the
labeling of goldfish optic nerve proteins was monitored over a 7 week
period of regeneration following a lesion to the optic tract. Labeled
phosphate incorporation into total nerve protein increased to a peak value
about twice that in normal nerve at 3 weeks after injury, then declined to
slightly above normal by 7 weeks. Incorporation of 3H- proline showed a
higher rise and a steeper decline, with values still significantly above
normal at 7 weeks. Two-dimensional gel electrophoresis revealed that almost
all the individual proteins examined underwent an increase in 3H-proline
incorporation with a peak at about 3 weeks. However, only 4 proteins showed
an increase in incorporation of 32P correlated with the increase in
3H-proline. The closest correlation was seen for protein 4, the equivalent
of the growth-associated protein GAP-43; for the other 3 proteins (15, 31,
and 38) 32P incorporation remained elevated even when 3H-proline
incorporation had declined. Two other proteins (24e and 48) showed
increased 32P incorporation not correlated with 3H-proline changes. Several
proteins showed a decrease in 32P incorporation, even though 3H- proline
incorporation was increased. For example, the phosphorylation of ON2, a
neuronal intermediate filament protein, showed a long-lasting decline,
which was already evident at 1 week and had not yet returned to normal by 7
weeks. Other proteins in this group (33, 37, and 46) showed a faster
recovery.(ABSTRACT TRUNCATED AT 250 WORDS)