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. 1976 Jun 1;67(6):691–702. doi: 10.1085/jgp.67.6.691

Patterns of proteins synthesized in the R15 neuron of Aplysia. Temporal studies and evidence for processing

PMCID: PMC2214982  PMID: 932671

Abstract

The time-course of changes in the pattern of newly synthesized proteins in the R15 neuron of the parietovisceral ganglion of Aplysia californica has been studied at 14 degrees C. 5% polyacrylamide gels containing sodium dodecyl sulfate (SDS) have been used to separate newly synthesized (leucine-labeled) proteins from the neuron. We have demonstrated that the pattern of newly synthesized proteins from the R15 neuron does not change significantly if 5-h pulses of labeled leucine are given during the first 72 h of in vitro incubation of the excised ganglion. However, the level of leucine incorporation begins to decline somewhere between 17 and 43 h after the ganglion is isolated; at 43 and 69 h the levels of incorporation fell to 29 and 10% of the initial level, respectively. A number of conclusions have been drawn from the use of a sequential, double-label type of experiment in the same cell. There is processing of SDS-soluble, 12,000-dalton (12k) material to 6,000-9,000-dalton (6-9k) material. These materials are the two major peaks on gels after long labeling periods and together account for about 35% of all newly synthesized proteins. After synthesis of 12k material, there is a gradual disappearance of 12k (half-life about 8 h) and simultaneous appearance of 6-9k material on the gels, as the postsynthesis "chase" period of ganglia incubation is increased. The processing of 12k to 6-9k material occurs even in the presence of anisomycin, a protein syntehsis inhibitor, during the chase period. While the rate of 12k to 6-9k conversion can vary from cell to cell, it appears to remain consistent within, and is characteristic of, any individual R15. We detect no circadian rhythm in either the rate of 12k synthesis or the rate of 12k to 6-9k processing with 5-h label periods. These results are discussed in relation to the roles of 12k and 6-9k material in the R15 neuron.

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Selected References

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  1. Arch S. Biosynthesis of the egg-laying hormone (ELH) in the bag cell neurons of Aplysia californica. J Gen Physiol. 1972 Jul;60(1):102–119. doi: 10.1085/jgp.60.1.102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Audesirk G., Strumwasser F. Circadian Rhythm of Neuron R15 of Aplysia californica: In Vivo Photoentrainment. Proc Natl Acad Sci U S A. 1975 Jun;72(6):2408–2412. doi: 10.1073/pnas.72.6.2408. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Berry R. W. Functional correlates of low molecular weight peptide synthesis in Aplysia neurons. Brain Res. 1975 Mar 21;86(2):323–333. doi: 10.1016/0006-8993(75)90706-4. [DOI] [PubMed] [Google Scholar]
  4. EAGLE H. Amino acid metabolism in mammalian cell cultures. Science. 1959 Aug 21;130(3373):432–437. doi: 10.1126/science.130.3373.432. [DOI] [PubMed] [Google Scholar]
  5. Gainer H., Barker J. L. Selective modulation and turnover of proteins in identified neurons of Aplysia. Comp Biochem Physiol B. 1975 Jun 15;51(2):221–227. doi: 10.1016/0305-0491(75)90212-6. [DOI] [PubMed] [Google Scholar]
  6. Gainer H., Barker J. L. Synaptic regulation of specific protein synthesis in an identified neuron. Brain Res. 1974 Sep 27;78(2):314–319. doi: 10.1016/0006-8993(74)90555-1. [DOI] [PubMed] [Google Scholar]
  7. Gainer H. Micro disc electrophoresis in sodium dodecyl sulfate: an application to the study of protein synthesis in individual, identified neurons. Anal Biochem. 1971 Dec;44(2):589–605. doi: 10.1016/0003-2697(71)90248-x. [DOI] [PubMed] [Google Scholar]
  8. Gainer H., Wollberg Z. Specific protein metabolism in identifiable neurons of Aplysia californica. J Neurobiol. 1974;5(3):243–261. doi: 10.1002/neu.480050306. [DOI] [PubMed] [Google Scholar]
  9. Kupfermann I., Weiss K. Water regulation by a presumptive hormone contained in identified neurosecretory cell R15 of Aplysia. J Gen Physiol. 1976 Jan;67(1):113–123. doi: 10.1085/jgp.67.1.113. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Lickey M. E. Seasonal modulation and non-24-hour entrainment of a circadian rhythm in a single neuron. J Comp Physiol Psychol. 1969 May;68(1):9–17. doi: 10.1037/h0027634. [DOI] [PubMed] [Google Scholar]
  11. Loh Y. P., Gainer H. Low molecular weight specific proteins in identified molluscan neurons. II. Processing, turnover, and transport. Brain Res. 1975 Jul 11;92(2):193–205. doi: 10.1016/0006-8993(75)90269-3. [DOI] [PubMed] [Google Scholar]
  12. Loh Y. P., Peterson R. P. Protein synthesis in phenotypically different, single neurons of Aplysia. Brain Res. 1974 Sep 20;78(1):83–98. doi: 10.1016/0006-8993(74)90355-2. [DOI] [PubMed] [Google Scholar]
  13. Schwartz J. H., Castellucci V. F., Kandel E. R. Functioning of identified neurons and synapses in abdominal ganglion of Aplysia in absence of protein synthesis. J Neurophysiol. 1971 Nov;34(6):939–953. doi: 10.1152/jn.1971.34.6.939. [DOI] [PubMed] [Google Scholar]
  14. Strumwasser F. Seventeenth Bowditch lecture. Neural and humoral factors in the temporal organization of behavior. Physiologist. 1973 Feb;16(1):9–42. [PubMed] [Google Scholar]
  15. Strumwasser F. The cellular basis of behavior in Aplysia. J Psychiatr Res. 1971 Aug;8(3):237–257. doi: 10.1016/0022-3956(71)90022-7. [DOI] [PubMed] [Google Scholar]
  16. Ward S., Wilson D. L., Gilliam J. J. Methods for fractionation and scintillation counting of radioisotope-labeled polyacrylamide gels. Anal Biochem. 1970 Nov;38(1):90–97. doi: 10.1016/0003-2697(70)90158-2. [DOI] [PubMed] [Google Scholar]
  17. Wilson D. L., Berry R. W. The effect of synaptic stimulation of RNA and protein metabolism in the R2 soma of aplysia. J Neurobiol. 1972;3(4):369–379. doi: 10.1002/neu.480030409. [DOI] [PubMed] [Google Scholar]
  18. Wilson D. L. Molecular weight distribution of proteins synthesized in single, identified neurons of Aplysia. J Gen Physiol. 1971 Jan;57(1):26–40. doi: 10.1085/jgp.57.1.26. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Wilson D. L. Protein synthesis and nerve cell specificity. J Neurochem. 1974 Mar;22(3):465–467. doi: 10.1111/j.1471-4159.1974.tb07616.x. [DOI] [PubMed] [Google Scholar]

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