Open AccessA fusion pore phenotype in mast cells of the ruby-eye mouse
Author(s) -
Andrés F. Oberhauser,
Julio M. Fernández
Publication year - 1996
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.93.25.14349
Subject(s) - exocytosis , phenotype , microbiology and biotechnology , lipid bilayer fusion , wild type , secretory vesicle , biology , vesicle , chemistry , biophysics , secretion , mutant , genetics , biochemistry , gene , membrane
Using patch-clamp capacitance and amperometric techniques, we have identified an exocytotic phenotype that affects the function of the fusion pore, the molecular structure that connects the lumen of a secretory vesicle with the extracellular environment during exocytosis. Direct observation of individual exocytotic events in mast cells from the ruby-eye mouse (ru /ru ) showed a 3-fold increase in the fraction and duration of transient fusion events with respect to wild-type mice. The fraction of the total fusion events that were transient increased from 0.22 ± 0.02 (wild type) to 0.65 ± 0.02 (ru /ru ), and the average duration of these events increased from 418 ± 32 ms (wild type) to 1207 ± 89 ms (ru /ru ). We also show that this phenotype can reduce and delay an evoked secretory response by causing the fusion of vesicles that have been previously emptied by repeated cycles of transient fusion. The exocytotic phenotype that we describe here may be a cause of diseases like platelet storage pool deficiency and prolonged bleeding times for which the ruby-eye mouse serves as an animal model. Furthermore, the identification of the gene causing the fusion pore phenotype reported here will illuminate the molecular mechanisms regulating exocytotic fusion.