Vesicle fusion and fission in plants and yeast

- Unitary exo- and endocytotic events are resolved in plant and yeast cells by high-resolution capacitance measurements.
- Plant and yeast cells execute permanent as well as transient fusion/fission of vesicles with the plasma membrane.
- The frequency of unitary exocytotic events corresponds to the overall increase in cell surface in growing yeast protoplasts.
- The general mechanisms of unitary exo- and endocytosis events in plant and fungal cells are similar to those in animal cells.

Measurements of the membrane capacitance on animal cells has provided an excellent technique for monitoring of exo- and endocytotic activity in intact living cells. Here we review recent data in which the same technique was applied to plant cells and cells of the budding yeast Saccharomyces cerevisiae. The data show that unitary exo- and endocytotic events can also be measured with the same technique after removing the cell wall from these cells. The resulting protoplasts execute the same type of transient and permanent fusion/fission that is known from animal cells. Also the size of the vesicles, which are fusing or budding, are of the same order of magnitude as those recorded in animal cells. Together these data support the view of an evolutionary conserved mechanism for unitary exo- and endocytosis events in eukaryotes. The successful recordings of exo- and endocytotic activity in Saccharomyces cerevisiae by capacitance measurements now pave the way for correlating the abundant information on the molecular machinery of exo- and endocytosis in this model organism with distinct functional properties.

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