The effect of experimental diabetes on the phosphorylation of proteins in the rat sciatic nerve was studied. Nerves from animals made diabetic with streptozocin were incubated in vitro with [32P]orthophosphate and divided into segments from the proximal to the distal end, and proteins from each segment were then separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The principal labeled species were the major myelin proteins, P0, and the basic proteins. After 6 wk of diabetes, the incorporation of isotope into these proteins rose as a function of distance along the nerve in a proximal to distal direction and was significantly higher at the distal end compared with incorporation into nerves from age-matched controls. The overall level of isotope uptake was similar in nerves from diabetic animals and weight-matched controls. The distribution of 32P among proteins also differed in diabetic nerve compared with both control groups in that P0 and the small basic protein accounted for a greater proportion of total label incorporated along the entire length of nerve. In contrast to intact nerve, there was no significant difference in protein phosphorylation when homogenates from normal and diabetic nerve were incubated with [32P]-γ-ATP. The results suggest that abnormal protein phosphorylation, particularly of myelin proteins, is a feature of experimental diabetic neuropathy and that the changes are most pronounced in the distal portion of the nerve.
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Original Contributions|
November 01 1987
Altered Protein Phosphorylation in Sciatic Nerve From Rats With Streptozocin-Induced Diabetes
Loes H Schrama;
Loes H Schrama
Department of Biochemical and Biophysical Sciences, University of Houston
Houston, Texas
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Liliana N Berti-Mattera;
Liliana N Berti-Mattera
Department of Biochemical and Biophysical Sciences, University of Houston
Houston, Texas
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Joseph Eichberg
Joseph Eichberg
Department of Biochemical and Biophysical Sciences, University of Houston
Houston, Texas
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Address correspondence and reprint requests to Joseph Eichberg, PhD, Department of Biochemical and Biophysical Sciences, University of Houston, 4800 Calhoun Road, Houston, TX 77004
Diabetes 1987;36(11):1254–1260
Article history
Received:
August 11 1986
Revision Received:
April 02 1987
Accepted:
April 02 1987
PubMed:
3666317
Citation
Loes H Schrama, Liliana N Berti-Mattera, Joseph Eichberg; Altered Protein Phosphorylation in Sciatic Nerve From Rats With Streptozocin-Induced Diabetes. Diabetes 1 November 1987; 36 (11): 1254–1260. https://doi.org/10.2337/diab.36.11.1254
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