Skip to main content
NCBI home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1963 Jan 1;16(1):1–23. doi: 10.1083/jcb.16.1.1

SYNTHESIS AND MIGRATION OF PROTEINS IN THE CELLS OF THE EXOCRINE PANCREAS AS REVEALED BY SPECIFIC ACTIVITY DETERMINATION FROM RADIOAUTOGRAPHS

H Warshawsky 1, C P Leblond 1, B Droz 1
PMCID: PMC2106192  PMID: 13999005

Abstract

Radioautographs of pancreatic acinar cells were prepared in rats and mice sacrificed at various times after injection of leucine-, glycine-, or methionine-H3. Measurements of radioactivity concentration (number of silver grains per unit area) and relative protein concentration (by microspectrophotometry of Millon-treated sections) yielded the mean specific activity of proteins in various regions of the acinar cells. The 2 to 5 minute radioautographs as well as the specific activity time curves demonstrate protein synthesis in ergastoplasm. From there, most newly synthesized proteins migrate to and accumulate in the Golgi zone. Then they spread to the whole zymogen region and, finally, enter the excretory ducts. An attempt at estimating turnover times indicated that two classes of proteins are synthesized in the ergastoplasm: "sedentary" with a slow turnover (62.5 hours) and "exportable" with rapid turnover (4.7 minutes). It is estimated that the exportable proteins spend approximately 11.7 minutes in the Golgi zone where they are built up into zymogen granules, and thereafter 36.0 minutes as fully formed zymogen granules, before they are released outside the acinar cell as pancreatic secretion. The mean life span of a zymogen granule in the cell is estimated to be 47.7 minutes.

Full Text

The Full Text of this article is available as a PDF (1.8 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BORSOOK H., DEASY C. L., HAAGENSMIT A. J., KEIGHLEY G., LOWY P. H. Metabolism of C14 labeled glycine, L-histidine, L-leucine, and L-lysine. J Biol Chem. 1950 Dec;187(2):839–848. [PubMed] [Google Scholar]
  2. CARO L. G. Electron microscopic radioautography of thin sections: the Golgi zone as a site of protein concentration in pancreatic acinar cells. J Biophys Biochem Cytol. 1961 May;10:37–45. doi: 10.1083/jcb.10.1.37. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. CARO L. G., PALADE G. E. [The role of the Golgi apparatus in the secretory process. Autoradiographic study]. C R Seances Soc Biol Fil. 1961;155:1750–1762. [PubMed] [Google Scholar]
  4. DESNUELLE P., ROVERY M. The proteins of the exocrine pancreas. Adv Protein Chem. 1961;16:139–195. doi: 10.1016/s0065-3233(08)60029-7. [DOI] [PubMed] [Google Scholar]
  5. DOUGHERTY J., GROSS J., LEBLOND C. P. Steady state of the thyroidal iodine. Endocrinology. 1951 Jun;48(6):700–713. doi: 10.1210/endo-48-6-700. [DOI] [PubMed] [Google Scholar]
  6. EARTLY H., GRAD B., LEBLOND C. P. The antagonistic relationship between testosterone and thyroxine in maintaining the epidermis of the male rat. Endocrinology. 1951 Dec;49(6):677–686. doi: 10.1210/endo-49-6-677. [DOI] [PubMed] [Google Scholar]
  7. FARQUHAR M. G., WELLINGS S. R. Electron microscopic evidence suggesting secretory granule formation within the Golgi apparatus. J Biophys Biochem Cytol. 1957 Mar 25;3(2):319–322. doi: 10.1083/jcb.3.2.319. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. GODIN C. Amino acid-protein interactions. Can J Biochem Physiol. 1960 Jul;38:805–806. [PubMed] [Google Scholar]
  9. HENDERSON L. M., SCHURR P. E., ELVEHJEM C. A. The influence of fasting and nitrogen deprivation on the concentration of free amino acids in rat plasma. J Biol Chem. 1949 Feb;177(2):815–823. [PubMed] [Google Scholar]
  10. LEBLOND C. P., EVERETT N. B., SIMMONS B. Sites of protein synthesis as shown by radioautography after administration of S35-labelled methionine. Am J Anat. 1957 Sep;101(2):225–271. doi: 10.1002/aja.1001010203. [DOI] [PubMed] [Google Scholar]
  11. MENDELSOHN M. L. The two-wavelength method of microspectrophotometry. II. A set of tables to facilitate the calculations. J Biophys Biochem Cytol. 1958 Jul 25;4(4):415–424. doi: 10.1083/jcb.4.4.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. MORRIS A. J., DICKMAN S. R. Biosynthesis of ribonuclease in mouse pancreas. J Biol Chem. 1960 May;235:1404–1408. [PubMed] [Google Scholar]
  13. ORNSTEIN L. The distributional error in microspectrophotometry. Lab Invest. 1952;1(2):250–265. [PubMed] [Google Scholar]
  14. PALADE G. E., SIEKEVITZ P. Pancreatic microsomes; an integrated morphological and biochemical study. J Biophys Biochem Cytol. 1956 Nov 25;2(6):671–690. doi: 10.1083/jcb.2.6.671. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. PATAU K. Absorption microphotometry of irregular-shaped objects. Chromosoma. 1952;5(4):341–362. doi: 10.1007/BF01271492. [DOI] [PubMed] [Google Scholar]
  16. SHEFFNER A. L., BERGEIM O. Effects of adrenocorticotropic hormone (ACTH) upon free amino acid levels of plasma and tissues. Arch Biochem Biophys. 1954 Apr;49(2):327–334. doi: 10.1016/0003-9861(54)90202-7. [DOI] [PubMed] [Google Scholar]
  17. SHELDON H., KIMBALL F. B. Studies on cartilage. III. The occurrence of collagen within vacuoles of the golgi apparatus. J Cell Biol. 1962 Mar;12:599–613. doi: 10.1083/jcb.12.3.599. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. SIEKEVITZ P., PALADE G. E. A cytochemical study on the pancreas of the guinea pig. 5. In vivo incorporation of leucine-1-C14 into the chymotrypsinogen of various cell fractions. J Biophys Biochem Cytol. 1960 Jul;7:619–630. doi: 10.1083/jcb.7.4.619. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. SIEKEVITZ P., PALADE G. E. A cytochemical study on the pancreas of the guinea pig. II. Functional variations in the enzymatic activity of microsomes. J Biophys Biochem Cytol. 1958 May 25;4(3):309–318. doi: 10.1083/jcb.4.3.309. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. SJOSTRAND F. S., HANZON V. Ultrastructure of Golgi apparatus of exocrine cells of mouse pancreas. Exp Cell Res. 1954 Nov;7(2):415–429. doi: 10.1016/s0014-4827(54)80087-5. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES