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. 1990 Jul 1;111(1):79–86. doi: 10.1083/jcb.111.1.79

Anchorage of secretion-competent dense granules on the plasma membrane of bovine platelets in the absence of secretory stimulation

PMCID: PMC2116172  PMID: 2365736

Abstract

The ultrastructural changes in electropermeabilized bovine platelets that accompany the Ca2(+)-induced secretion of serotonin were investigated in ultra-thin sections of chemically fixed cells. Such preparations permitted us to study both the localization of and the structures associated with serotonin-containing dense granules. Localization of dense granules within cells was examined by measuring the shortest distances between the granular membranes and the plasma membrane. About 40% of total granules were located close to the plasma membrane at an average distance of 10.8 +/- 1.6 nm. 71% of the total number of granules were localized at a similar average distance of 12.5 +/- 2.7 nm in intact platelets. The percentage of granules apposed to the plasma membrane corresponded closely to the percentage of total serotonin that was maximally secreted after stimulation of the permeabilized (38 +/- 4.9%) and the intact platelets (72 +/- 3.6%). Furthermore, the percentage of granules anchored to the membrane, but not of those in other regions of permeabilized cells, decreased markedly when cells were stimulated for 30 s by extracellularly added Ca2+. The decrease in the numbers of granules in the vicinity of the plasma membrane corresponded to approximately 22% of the total number of dense granules that were used for measurements of the distances between the two membranes and corresponded roughly to the overall decrease (15%) in the average number of the granules per cell. Most dense granules were found to be associated with meshwork structures of microfilaments. Upon secretory stimulation, nonfilamentous, amorphous structures found between the plasma membrane and the apposed granules formed a bridge-like structure that connected both membranes without any obvious accompanying changes in the microfilament structures. These results suggest that the dense granules that are susceptible to secretory stimulation are anchored to the plasma membrane before stimulation, and that the formation of the bridge-like structure may participate in the Ca2(+)-regulated exocytosis.

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Selected References

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  1. Begg D. A., Rodewald R., Rebhun L. I. The visualization of actin filament polarity in thin sections. Evidence for the uniform polarity of membrane-associated filaments. J Cell Biol. 1978 Dec;79(3):846–852. doi: 10.1083/jcb.79.3.846. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bennett H., Condeelis J. Decoration with myosin subfragment-1 disrupts contacts between microfilaments and the cell membrane in isolated Dictyostelium cortices. J Cell Biol. 1984 Oct;99(4 Pt 1):1434–1440. doi: 10.1083/jcb.99.4.1434. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Burgoyne R. D. Mechanisms of secretion from adrenal chromaffin cells. Biochim Biophys Acta. 1984 Jun 25;779(2):201–216. doi: 10.1016/0304-4157(84)90009-1. [DOI] [PubMed] [Google Scholar]
  4. Chandler D. E., Heuser J. E. Arrest of membrane fusion events in mast cells by quick-freezing. J Cell Biol. 1980 Aug;86(2):666–674. doi: 10.1083/jcb.86.2.666. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Durham A. C. A unified theory of the control of actin and myosin in nonmuscle movements. Cell. 1974 Jul;2(3):123–135. doi: 10.1016/0092-8674(74)90087-7. [DOI] [PubMed] [Google Scholar]
  6. Fowler V. M., Pollard H. B. Chromaffin granule membrane-F-actin interactions are calcium sensitive. Nature. 1982 Jan 28;295(5847):336–339. doi: 10.1038/295336a0. [DOI] [PubMed] [Google Scholar]
  7. Fowler V. M., Pollard H. B. In vitro reconstitution of chromaffin granule-cytoskeleton interactions: ionic factors influencing the association of F-actin with purified chromaffin granule membranes. J Cell Biochem. 1982;18(3):295–311. doi: 10.1002/jcb.1982.240180305. [DOI] [PubMed] [Google Scholar]
  8. Holz R. W., Bittner M. A., Peppers S. C., Senter R. A., Eberhard D. A. MgATP-independent and MgATP-dependent exocytosis. Evidence that MgATP primes adrenal chromaffin cells to undergo exocytosis. J Biol Chem. 1989 Apr 5;264(10):5412–5419. [PubMed] [Google Scholar]
  9. Kelly R. B. The cell biology of the nerve terminal. Neuron. 1988 Aug;1(6):431–438. doi: 10.1016/0896-6273(88)90174-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Knight D. E., Niggli V., Scrutton M. C. Thrombin and activators of protein kinase C modulate secretory responses of permeabilised human platelets induced by Ca2+. Eur J Biochem. 1984 Sep 3;143(2):437–446. doi: 10.1111/j.1432-1033.1984.tb08391.x. [DOI] [PubMed] [Google Scholar]
  11. Kondo H., Wolosewick J. J., Pappas G. D. The microtrabecular lattice of the adrenal medulla revealed by polyethylene glycol embedding and stereo electron microscopy. J Neurosci. 1982 Jan;2(1):57–65. doi: 10.1523/JNEUROSCI.02-01-00057.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Maupin P., Pollard T. D. Improved preservation and staining of HeLa cell actin filaments, clathrin-coated membranes, and other cytoplasmic structures by tannic acid-glutaraldehyde-saponin fixation. J Cell Biol. 1983 Jan;96(1):51–62. doi: 10.1083/jcb.96.1.51. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Nakata T., Hirokawa N. Cytoskeletal reorganization of human platelets after stimulation revealed by the quick-freeze deep-etch technique. J Cell Biol. 1987 Oct;105(4):1771–1780. doi: 10.1083/jcb.105.4.1771. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Oho C., Takisawa H. Distinct occurrence of phosphatidylinositol 4,5-bisphosphate-induced Ca2+ release and inositol 1,4,5-triphosphate-induced release in ATP-dependent Ca2+-transporting platelet microsomes. J Biochem. 1986 Oct;100(4):911–921. doi: 10.1093/oxfordjournals.jbchem.a121804. [DOI] [PubMed] [Google Scholar]
  15. Schäfer T., Karli U. O., Schweizer F. E., Burger M. M. Docking of chromaffin granules--a necessary step in exocytosis? Biosci Rep. 1987 Apr;7(4):269–279. doi: 10.1007/BF01121448. [DOI] [PubMed] [Google Scholar]
  16. WEISSBACH H., WAALKES T. P., UDENFRIEND S. A simplified method for measuring serotonin in tissues; simultaneous assay of both serotonin and histamine. J Biol Chem. 1958 Feb;230(2):865–871. [PubMed] [Google Scholar]
  17. White J. G. The secretory pathway of bovine platelets. Blood. 1987 Mar;69(3):878–885. [PubMed] [Google Scholar]

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