Studies on membrane fusion. III. The role of calcium-induced phase changes

Papahadjopoulos, D.; Vail, William J.; Newton, C.; Nir, Shlomo; Jacobson, Kenneth A.; Poste, George; Lazo, R.

doi:10.1016/0005-2736(77)90275-9

Cited by 435 publications

(208 citation statements)

References 37 publications

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“…In particular, observations made on the mechanism of the Ca2+-induced fusion of phosphatidylserine vesicles were taken to indicate that a phase change from a fluid to a solid state is a key factor in fusion induced by Ca2+ [42]. They proposed that the crucial event in fusion responsible for triggering most, and perhaps all membrane fusion phenomena, is a Ca2+ -induced separation of acidic phospholipids such as phosphatidylserine into rigid crystalline domains, with fusion occurring at domain boundaries between adjacent membranes [43].…”

Section: I) Cakium Ionsmentioning

confidence: 99%

Do hydrophobic sequences cleaved from cellular polypeptides induce membrane fusion reactions in vivo?

Lucy

1984

FEBS Letters

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The concept that a direct interaction between Ca2+ and phospholipids is a major factor in membrane fusion reactions is questioned. Attention is drawn to a number of findings on associations between fusion and the proteolysis of membrane proteins. It is proposed that hydrophobic polypeptides, which are functionally comparable to the fusogenic proteins of certain viruses but which are produced in cells by the endogenous proteolysis of membrane and cellular proteins, may induce membrane fusion reactions in vivo.

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Section: I) Cakium Ionsmentioning

confidence: 99%

Do hydrophobic sequences cleaved from cellular polypeptides induce membrane fusion reactions in vivo?

Lucy

1984

FEBS Letters

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“…Therefore, a marked increase of membrane fusion can be observed in the range of the specific transition temperature of the lipids investigated [10,11,58,57]. Fusion of secretory vesicles exhibits no discontinuity with temperature.…”

Section: Temperature Dependencementioning

confidence: 99%

“…Fusion of phospholipid vesicles was induced by Ca 2 + at concentrations of 0.1 mM or greater, depending on the type of phospholipids studied [11,47,51,55,57,58]. The requirement for such high concentration of Ca 2+ contrasts with the low concentrations of Ca 2 + (10-7 M) sufficient to induce fusion of secretory vesicles.…”

Section: Ca2+-speco~'icity Antagonism With Mg 2+ and Temperature Depmentioning

confidence: 99%

“…The requirement for such high concentration of Ca 2+ contrasts with the low concentrations of Ca 2 + (10-7 M) sufficient to induce fusion of secretory vesicles. In addition phospholipid fusion can also be induced by other cations [11,47,51,58], certain phospholipids being more susceptible to fusion by Ca 2+ than by Mg 2+ [51,57,58]. In contrast, fusion of secretory vesicles isolated from rat liver is specifically governed by Ca 2 +.…”

Section: Ca2+-speco~'icity Antagonism With Mg 2+ and Temperature Depmentioning

confidence: 99%

“…Membrane fluidity seems to be an important prerequisite for the fusion of pure phospholipid membranes since the rate of fusion increases dramatically at or above the phase transition of the phospholipids [10,11,57,58]. The fusion of secretory vesicles isolated from rat liver displayed no abrupt changes between 2 and 37 ~ The detection of membrane fusion of biological membranes in vitro at low temperatures is not surprising: Exposed to cold, neurohypophyses [21], synaptosomes [62], and neurosecretosomes [4] release secretory products in the absence or presence of an external stimulus.…”

Section: Ca2+-speco~'icity Antagonism With Mg 2+ and Temperature Depmentioning

confidence: 99%

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Fusion of secretory vesicles isolated from rat liver

Gratzl

Dahl

1978

J. Membrain Biol.

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Summary. Secretory vesicles isolated from rat liver were found to fuse after exposure to Ca 2 +. Vesicle fusion is characterized by the occurrence of twinned vesicles with a continuous cleavage plane between two vesicles in freeze-fracture electron microscopy. The number of fused vesicles increases with increasing Ca 2 +-concentrations and is half maximal around 10 -6 M. Other divalent cations (Ba 2+, Sr 2+, and Mg 2+) were ineffective. Mg 2+ inhibits Ca2+-induced fusion. Therefore, the fusion of secretory vesicles in vitro is Ca z+ specific and exhibits properties similar to the exocytotic process of various secretory cells.Various substances affecting secretion in vivo (microtubular inhibitors, local anesthetics, ionophores) were tested for their effect on membrane fusion in our system.The fusion of isolated secretory vesicles from liver was found to differ from that of pure phospholipid membranes in its temperature dependence, in its much lower requirement for Ca 2+, and in its Cag+-specificity. Chemical and enzymatic modifications of the vesicle membrane indicate that glycoproteins may account for these differences.Membrane fusion is an essential event in a variety of cell functions such as cell fusion, uptake of extracellular material (endocytosis) and release of cell products (exocytosis). Elucidation of the molecular mechanism of membrane fusion has been hampered by the lack of suitable systems for studying this process. Studies with intact cells have not yielded data which lead to ready interpretation concerning subcellular processes. On the other hand, studies with artificial membranes may be only tangentially related to the fusion of biological membranes.Recently our group investigated the fusion of isolated biological membranes [16,17,31,33,69,74]. We observed that Ca 2+ specifically induces the fusion of isolated secretory vesicles in a buffered sucrose medium.Intervesicular fusion of secretory vesicles, as well as the interaction between the cell membrane and the vesicle membrane, was observed in a variety of secretory cells [2,3,6,18,29,39,53,65]. Douglas [20] showed that in "compound exocytosis" by mast cells an external stimulus initiates fusion between secretory vesicle membranes and the

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Organic and Inorganic Osmolytes at Lipid Membrane Interfaces

Westh

Peters

2008

Structure and Dynamics of Membranous Interfaces

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Studies on membrane fusion. III. The role of calcium-induced phase changes

Cited by 435 publications

References 37 publications

Do hydrophobic sequences cleaved from cellular polypeptides induce membrane fusion reactions in vivo?

Do hydrophobic sequences cleaved from cellular polypeptides induce membrane fusion reactions in vivo?

Fusion of secretory vesicles isolated from rat liver

Organic and Inorganic Osmolytes at Lipid Membrane Interfaces

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