Sutter, Jens and Denecke, Juergen and Thiel, Gerhard (2012) Synthesis of vesicle cargo determines amplitude of Ca2+-sensitive exocytosis. Cell Calcium, 52 (3-4). pp. 283-288. ISSN 0143-4160Full text not available in this repository. (Request a copy from the Strathclyde author)
Here we examine the potential coupling between the synthesis of secretory proteins and the sensitivity of exocytosis to the concentration of free Ca2+ in the cytosol ([Ca2+](i)) in plant cell. We therefore monitor in tobacco protoplasts the excursion of the membrane capacitance in response to an elevation of[Ca2+](i) as a measure for exocytotic activity. The data show that a ramp like elevation of [Ca2+](i) generates in protoplasts from wild type plants and from transgenic plants, which overexpress the secreted alpha-amylase, an exocytotic burst with an initial steep and a subsequent slow phase. The largest capacitive burst is obtained in alpha-amylase producing plants and the amplitude of the [Ca2+](i) evoked C-m excursion is a function of the amylase synthesis of the plants. The data support a model according to which plant cells have at least two serial [Ca2+](i) sensitive processes in the final steps of their exocytotic pathway. The overproduction of a secreted cargo does not affect the kinetics of this process but the number of vesicles in pools upstream of the [Ca2+](i) sensitive steps. (C) 2012 Elsevier Ltd. All rights reserved.
|Keywords:||vesicle cargo, synthesis, amplitude, Ca2+-sensitive exocytosis, tobacco, amylase, exocytosis, Physics, Cell Biology, Molecular Biology, Physiology|
|Subjects:||Science > Physics|
|Department:||Faculty of Science > Physics|
|Depositing user:||Pure Administrator|
|Date Deposited:||05 Dec 2012 14:36|
|Last modified:||07 Jan 2017 01:40|