Posttranslational Protein Modification by Amino Acid Addition in Intact and Regenerating Axons of the Rat Sciatic Nerve
| Autor: | J. A. Sturman, M. F. Zanakis, Goutam Chakraborty, Nicholas A. Ingoglia |
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| Rok vydání: | 1984 |
| Předmět: |
Male
Hot Temperature Arginine Acylation Lysine Nerve Tissue Proteins Axonal Transport Biochemistry Cellular and Molecular Neuroscience RNA Transfer Endopeptidases Aspartic acid Animals Amino Acids chemistry.chemical_classification Molecular mass Chemistry Rats Inbred Strains Sciatic Nerve Axons Nerve Regeneration Rats Amino acid Sciatic nerve Endopeptidase K Leucine Chromatography column Protein Processing Post-Translational Ultracentrifugation |
| Zdroj: | Journal of Neurochemistry. 43:1286-1294 |
| ISSN: | 1471-4159 0022-3042 |
| Popis: | Experiments were performed to determine whether ppsttranslational addition of amino acids to axonal proteins occurs in axons of the rat sciatic nerve. Two ligatures were placed 1 cm apart on sciatic nerves. Six days later, segments proximal to each ligature were removed, homogenized, centrifuged at 150,000 ·g, and analyzed for the ability to incorporate 3H-amino acids into proteins. No incorporation of amino acids into proteins was found in the high-speed supernatant, but when the supernatant was passed through a Sephacryl S-200 chromatography column (removing molecules less than 20 kD), [3H]arginine, lysine, leucine and aspartic acid were incorporated into proteins in both proximal and distal nerve segments. Small but consistently greater amounts of radioactivity were incorporated into proteins in proximal segments compared with distal segments, indicating that the components necessary for the reaction are transported axonally. This reaction represents the posttranslational incorporation of a variety of amino acids into proteins of rat sciatic nerve axons. Other experiments showed that the incorporation of amino acids into proteins is by covalent bonding, that the amino acid donor is likely to be tRNA, and that the reaction is inhibited in vivo by a substance whose molecular mass is less than 20 kD. This inhibition is not affected by incubation with physiological concentrations of unlabeled amino acids, by boiling, or by treatment with Proteinase K. When the axonally transported component of the reaction was determined in regenerating nerves, the amount of incorporation of amino acids into protein was 15–150 times that in intact nerves. The results indicate that the components of this reaction are transported axonally in rat sciatic nerves and that the reaction is increased dramatically in growing axons during nerve regeneration. |
| Databáze: | OpenAIRE |
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