Alpha-latrotoxin triggers extracellular Ca2+-dependent exocytosis and sensitizes fusion machinery in endocrine cells

Zhitao Hu, Pin Zhao, Jie Liu, Zhengxin Wu, Tao Xu

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3 Citations (Scopus)


α-from the venom of black widow spider induces and augments neurotransmitter and hormone release by way of extracellular Ca2+ influx and cellular signal transduction pathways. By using whole cell current and capacitance recording, the photolysis of caged Ca2+, and Ca 2+ microfluorometry and amperometry, we investigated the stimulating effect and mechanism of α-latrotoxin on exocytosis in rat pancreatic β cells, LβT2 cells and latrophilin plasmid-transfected lNS-1 cells. Our data indicated that: (1) α-latrotoxin increased cytosolic Ca 2+ concentration through the formation of cation-permitting pores and subsequent Ca2+ influx with the presence of extracellular Ca 2+ (2) α-latrotoxin stimulated exocytosis in normal bath solution and its stimulating effect on secretion was eradicated in Ca 2+-free bath solution; and (3) α_ latrotoxin sensitized the molecular machinery of fusion through activation of protein kinase C and increased the response of cells to Ca2+ photolysed by a flash of ultraviolet light. In α latrotoxin induced exocytosis by way of Ca 2+ influx and accelerated vesicle fusion by the sensitization of fusion machinery.

Original languageEnglish
Article number16395521
Pages (from-to)8-14
Number of pages7
JournalActa Biochimica et Biophysica Sinica
Issue number1
Publication statusPublished - 2006
Externally publishedYes


  • α-latrotoxin
  • Amperometry
  • Ca-sensitivity of fusion
  • Calcium
  • Capacitance measurement
  • Exocytosis
  • Protein kinase C (PKC)

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