INTRACELLULAR TRANSPORT OF SECRETORY PROTEINS IN THE PANCREATIC EXOCRINE CELL
Open Access
- 1 December 1968
- journal article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 39 (3), 589-603
- https://doi.org/10.1083/jcb.39.3.589
Abstract
Since in the pancreatic exocrine cell synthesis and intracellular transport of secretory proteins can be uncoupled (1), it is possible to examine separately the metabolic requirements of the latter process. To this intent, guinea pig pancreatic slices were pulse labeled with leucine-(3)H for 3 min and incubated post-pulse for 37 min in chase medium containing 5 x 10(-4)M cycloheximide and inhibitors of glycolysis, respiration, or oxidative phosphorylation. In each case, the effect on transport was assessed by measuring the amount of labeled secretory proteins found in zymogen granule fractions isolated from the corresponding slices. This assay is actually a measure of the efficiency of transport of secretory proteins from the cisternae of the rough endoplasmic reticulum (RER) to the condensing vacuoles of the Golgi complex which are recovered in the zymogen granule fraction (16). The results indicate that transport is insensitive to glycolytic inhibitors (fluoride, iodoacetate) but is blocked by respiratory inhibitors (N(2), cyanide, Antimycin A) and by inhibitors of oxidative phosphorylation (dinitrophenol, oligomycin). Except for Antimycin A, the effect is reversible. Parallel radioautographic studies and cell fractionation procedures applied to microsomal subfractions have indicated that the energy-dependent step is located between the transitional elements of the RER and the small, smooth-surfaced vesicles at the periphery of the Golgi complex. Radiorespirometric data indicate that the substrates oxidized to support transport are endogenous long-chain fatty acids.Keywords
This publication has 15 references indexed in Scilit:
- INTRACELLULAR TRANSPORT OF SECRETORY PROTEINS IN THE PANCREATIC EXOCRINE CELLThe Journal of cell biology, 1968
- Metabolism of Glucose in the Islets of LangerhansJournal of Biological Chemistry, 1968
- INTRACELLULAR TRANSPORT OF SECRETORY PROTEINS IN THE PANCREATIC EXOCRINE CELLThe Journal of cell biology, 1967
- INTRACELLULAR TRANSPORT OF SECRETORY PROTEINS IN THE PANCREATIC EXOCRINE CELLThe Journal of cell biology, 1967
- The lipids of mammalian pancreasBiochemical Journal, 1966
- THE REGULATION OF PINOCYTOSIS IN MOUSE MACROPHAGESThe Journal of Experimental Medicine, 1966
- On the attachment of ribosomes to microsomal membranesJournal of Molecular Biology, 1966
- Vectorial discharge of peptides released by puromycin from attached ribosomes.Proceedings of the National Academy of Sciences of the United States of America, 1966
- Synthesis and transfer of amylase in pigeon pancreatic micromosomes.1966
- Factors Influencing the Rates of Long-Chain Fatty Acid Oxidation and Synthesis in Mammalian SystemsPhysiological Reviews, 1961