Latrotoxin-induced fusion of liposomes with bilayer phospholipid membranes

Sokolov, Yuri; Chanturia, Alexander N.; Lishko, V. K.

doi:10.1016/0005-2736(87)90345-2

Cited by 15 publications

(9 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The direct observation of tetramers inserted into artificial lipid membrane (Orlova et al 2000) indicates that the “bowl” formed by the body domains is immersed deeply in the lipid, while the wing domains remain splayed on, and slightly buried into, the extracellular surface of the bilayer, while the heads are exposed to the extracellular space (Figure 2). In this model, some regions of the body domains are exposed to the cytosol, consistent with the observation that protease treatment from that side of the lipid bilayer modifies the inserted channel (Robello et al 1984; Chanturia and Lishko 1992) and supportive of the hypotheses that α-LTX could interact with intracellular release machinery (Khvotchev et al 2000) or act as a fusogen catalysing vesicle fusion (Sokolov et al 1987; Lishko et al 1990). …”

Section: Membrane Poresupporting

confidence: 84%

α-Latrotoxin and Its Receptors

Ushkaryov

Rohou

Sugita

2008

Handbook of Experimental Pharmacology

View full text Add to dashboard Cite

alpha-Latrotoxin (alpha-LTX) from black widow spider venom induces exhaustive release of neurotransmitters from vertebrate nerve terminals and endocrine cells. This 130-kDa protein has been employed for many years as a molecular tool to study exocytosis. However, its action is complex: in neurons, alpha-LTX induces massive secretion both in the presence of extracellular Ca(2+) (Ca(2+) (e)) and in its absence; in endocrine cells, it usually requires Ca(2+) (e). To use this toxin for further dissection of secretory mechanisms, one needs an in-depth understanding of its functions. One such function that explains some alpha-LTX effects is its ability to form cation-permeable channels in artificial lipid bilayers. The mechanism of alpha-LTX pore formation, revealed by cryo-electron microscopy, involves toxin assembly into homotetrameric complexes which harbor a central channel and can insert into lipid membranes. However, in biological membranes, alpha-LTX cannot exert its actions without binding to specific receptors of the plasma membrane. Three proteins with distinct structures have been found to bind alpha-LTX: neurexin Ialpha, latrophilin 1, and receptor-like protein tyrosine phosphatase sigma. Upon binding a receptor, alpha-LTX forms channels permeable to cations and small molecules; the toxin may also activate the receptor. To distinguish between the pore- and receptor-mediated effects, and to study structure-function relationships in the toxin, alpha-LTX mutants have been used.

show abstract

Section: Membrane Poresupporting

confidence: 84%

α-Latrotoxin and Its Receptors

Ushkaryov

Rohou

Sugita

2008

Handbook of Experimental Pharmacology

View full text Add to dashboard Cite

show abstract

“…We supposed that LTX by itself could trigger the fusion process. The experiments with the model liposome-planar lipid membrane system [3] and with cell-free model of neurosecretion consisting of synaptic vesicles and synaptic plasma membrane [4] substantiates this assumption. In this paper, we have directly demonstrated the fusogenic activity of LTX in liposome experiments.…”

Section: Introduction 2 Materials and Methodsmentioning

confidence: 87%

Fusion of negatively charged phospholipid vesicles by α‐latrotoxin

Lishko¹,

Terletskaya²,

Тrikash³

1990

FEBS Letters

View full text Add to dashboard Cite

~t-Latrotoxin-induced fusion of liposomes has been described using large unilamellar vesicles composed of phosphatidylcholine/phosphatidylethanolamine/cardiolipin at a molar ratio of 2:3:5. Vesicle fusion was monitored by terbium/dipicolinic acid assay as well as by fluorescence energy transfer measurement. The enhancement of the fusogenic effect of LTX by low concentrations (0.1-3 mM) of CaC1 z has been demonstrated. The efficiency of other divalent cations on the LTX fusogenic activity was shown to decrease in the sequence Ca > Cd > Sr > Mg > Ba. LTX-induced fusion was accompanied by the increase of vesicle size measured by laser correlation spectroscopy. It is concluded that fusogenic action of LTX may be involved in its effect on synaptic apparatus.a-Latrotoxin; Membrane fusion; Liposome

show abstract

“…Now that we have a ready source of this small protein (baculovirus-infected cells), its role in toxin function can be further studied by the effect of its addition to systems in which a-latrotoxin is active [e.g. direct increase of secretive functions (Grasso et al, 1980); the formation in artificial lipid bilayers of stable conductance channels (Robello et al, 1984); the triggering of fusogenic properties (Sokolov et al, 1987)l. This approach will be further strengthened by preparing antibodies against the recombinant protein, immunopurified using the procedure described here, which are able to recognise native latrodectin and perhaps interfere with its function in these systems.…”

Section: Discussionmentioning

confidence: 99%

The Cloning of a cDNA Encoding a Protein (Latrodectin) which Co-purifies with the alpha-latrotoxin from the Black Widow Spider Latrodectus tredecimguttatus (Theridiidae)

et al. 1995

View full text Add to dashboard Cite

A cDNA encoding a polypeptide of 88 amino acids was cloned following the rapid amplification of cDNA ends (RACE) procedure using mRNA isolated from the venom glands of the Mediterranean black widow spider (Latrodectus tredecimguttutus) and oligonucleotides based on the sequence of a tryptic fragment putatively from a-latrotoxin. Apart from a potential signal peptide, the rest of this small protein, named latrodectin, was highly hydrophilic, having a calculated molecular mass of 7945 Da and a PI of 4.3. Northern-blot analysis showed that the mRNA was specifically expressed in the venom gland of L. tredecimguttutus and that it was well conserved between two geographically remote species (L. geometricus and L. indistinctus). A polyclonal serum raised in rabbits against the C-terminal sequence of latrodectin detected cross-reactive proteins in the venom fluid, venom gland extracts, and in purified a-latrotoxin, suggesting that latrodectin is intimately associated with a-latrotoxin. Finally, we produced a recombinant protein in a cell system infected with baculovirus and developed an immunoaffinity purification procedure for latrodectin to facilitate further structural and functional analyses of the molecule.

show abstract

Latrotoxin-induced fusion of liposomes with bilayer phospholipid membranes

Cited by 15 publications

References 19 publications

α-Latrotoxin and Its Receptors

α-Latrotoxin and Its Receptors

Fusion of negatively charged phospholipid vesicles by α‐latrotoxin

The Cloning of a cDNA Encoding a Protein (Latrodectin) which Co-purifies with the alpha-latrotoxin from the Black Widow Spider Latrodectus tredecimguttatus (Theridiidae)

Contact Info

Product

Resources

About