Calcium-Induced Displacement of Membrane-Associated Particles Upon Aggregation of Chromaffin Granules

Schober, R.; Nitsch, Cordula; Rinne, Ulrich; Morris, Stephen

doi:10.1126/science.835010

Cited by 52 publications

(7 citation statements)

References 22 publications

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“…In stimulated mast cells pentalaminar granule-to-granule fusion sites are smooth and particle-free in freeze-fracture replicas (18), and therefore they are presumed to be areas of lipid membrane from which membrane proteins have been excluded (4,6,33). Similarly, freeze-fracture replicas of isolated chromaffin granules, induced by calcium ions to aggregate in vitro, show particle-free contact areas which correspond to pentalaminar contacts in thin sections (29). Granule-to-granule contacts, as seen either in freeze-fracture replicas or in thin sections, are comparable to the particle-free, pentalaminar contact sites formed by a secretion granule membrane with the plasma membrane in a wide variety of cells engaged in exocytosis (5,7,16,18,24,25,27,28,31).…”

Section: Discussionmentioning

confidence: 99%

“…It has been postulated that a calcium,mediated flight or lateral displacement of membrane proteins occurs as membranes which are capable of fusion approach each other (1,5,8,18,(27)(28)(29). The intramembrane particle arrays which may predetermine and delimit fusion sites in plasma and mucocyst membranes of Tetrahymena (28) have not been observed during exocytosis in mammalian secretory cells (7,18,26).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Membrane interactions between adjacent mucols secretion granules.

Neutra¹,

Schaeffer²

1977

The Journal of Cell Biology

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In primate goblet cells, the membranes of adjacent mucous granules form contact areas which appear as extensive pentalaminar fusion sites in thin sections. In freeze-fracture replicas, the same membrane areas are smooth, except for a few 6-8-nm particles which adhere to the E face. These protein-poor membrane interaction sites are relatively long-lived, and it is proposed that further stimulus may be required to trigger membrane fission.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Membrane interactions between adjacent mucols secretion granules.

Neutra¹,

Schaeffer²

1977

The Journal of Cell Biology

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“…Close apposition of membranes with particle-free fracture faces has been seen in a number of cell systems (13,15,21,25,29,35,36) . Because the areas of close contact in these membranes are focal and not ordered in periodic arrays as in myelin, structural information is available only through microscopy.…”

Section: Close Contactmentioning

confidence: 99%

Compaction and particle segregation in myelin membrane arrays

Cj¹,

Dl²,

Melchior³

et al. 1981

The Journal of Cell Biology

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Compacted membrane arrays are formed in the nerve myelin sheath by lowering the water activity (through evaporation or immersion in hypertonic solutions of nonelectrolytes or monovalent salts) or by binding specific cations (Ca", La", and tetracaine at concentrations above 5-10 mM) . X-ray diffraction observations on intact, hydrated nerves treated to induce compaction provide a control to assess the significance of structural changes seen by freeze-fracture electron microscopy . Compaction inevitably leads to lateral segregation of particles away from the closely packed membrane arrays into contiguous normal, or slightly expanded, period arrays . In the particle-enriched layers, the E fracture face is more particledense than the P face, whereas no particles are found on either face in the compacted layers . Morphologically, compaction induced by the all-or-nothing, relatively irreversible action of specific cations cannot be distinguished from compaction to the same extent induced by the graded, reversible effects of nonelectrolytes . Compaction by sodium chloride resembles that by specific-cation binding in that the repeat period is independent of reagent concentration; but, like dehydration by nonelectrolytes, the extent of compaction is reversibly related to reagent concentration . Sodium chloride-compacted myelin can be distinguished morphologically by a lack of the elongated border particles at the boundary between smooth and particleenriched membrane observed for other compacting treatments . Fracture faces in compacted arrays are not always smooth, but the unusual appearances can be duplicated in purified myelin lipid multilayers subjected to similar treatments, which indicates that the particle-free membrane fracture faces are uninterrupted lipid hydrocarbon layers . Correlation of x-ray diffraction and electron microscopy observations provides a direct basis for identifying the intramembrane particles with transmembrane protein . The transmembrane protein appears to play a significant role in maintaining the normal membrane separation ; swelling of the particleenriched arrays in myelin compacted by tetracaine at low ionic strength provides information about the charge distribution on the transmembrane protein . Swelling of the compacted arrays following irreversible particle segregation shows that the interaction properties of the particlefree membranes are similar to those of pure lipid multilayers . Compaction and the consequent particle segregation in myelin results from conditions stabilizing close apposition of the lipid bilayers . Particle segregation in areas of close contact between other cell membranes may also be driven by interbilayer attractive forces .The crystal-like array of membranes in the nerve myelin sheath can be compacted or swollen by controlled changes in the environment . Compaction occurs when the water activity is lowered (7,8,10,14,16,32) or when the concentration of

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“…However, the membranes of vesic1es on the published micrographs are fragmented so that it remains unc1ear to what extent [46][47][48].…”

Section: Fusion 01 Liposomesmentioning

confidence: 99%

Membrane fusion of secretory vesicles and liposomes Two different types of fusion

Ekerdt

Dahl²,

Gratzl³

1981

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Secretory vesieles isolated from adrenal medulla were found to fuse in vitro in response to incubation with Ca 2 +. Intervesicular fusion was detected by electron microscopy and was indicated by the appearance of twinned vesieies in freeze-fractured suspensions of vesieles and in thin-sectioned pellet. Two types of fusion could be distinguished: Type I, occurring between 10-7 M and 10-4 M Ca 2 +, was specific for ea 2 +, was inhibited by other divalent cations and was abolished by pretreatment of vesieles with glutaraldehyde, neuraminidase or trypsin. Fusion type I was linear with temperature. A second type of intervesicular fusion was elicited by Ca 2 + in concentrations higher than 2.5 mM and was morphologically characterized by multiple fusions of secretory vesicles. This type of fusion was found to be similar to fusion of liposomes prepared from the membrane lipids of adrenal medullary secretory vesieles: ea 2 + could be replaced by other divalent cations, the effect of different divalent cations was additive and pretreatments attacking membrane proteins were ineffective. Fusion type 11 of intact secretory vesieies as weil as liposome fusion was discontinuous with temperature. Liposome fusion could be detected within 35 ms and persisted for 180 min. Using liposomes containing defined Ca 2 + concentrations we have not found a major influence of Ca 2 + asymmetry on fusion. Incorporation of the ganglioside GM 3 , which is present in the membranes of intact adrenal medullary secretory vesicles did not change the properties of liposomes fusion. Using a Ca 2 +-selective electrode we have identified in secretory vesiele membranes both high affinity binding sites for Ca 2 + (/(} = 1.6 . 10-6 M) and low affinity sites (/(} = 1.2· 10-4 M).

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Calcium-Induced Displacement of Membrane-Associated Particles Upon Aggregation of Chromaffin Granules

Cited by 52 publications

References 22 publications

Membrane interactions between adjacent mucols secretion granules.

Membrane interactions between adjacent mucols secretion granules.

Compaction and particle segregation in myelin membrane arrays

Membrane fusion of secretory vesicles and liposomes Two different types of fusion

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