Abstract
Dynamin-family proteins are self-assembling GTPases that are involved in membrane fission and fusion events. Although several models for its function have been proposed, the mechanism of dynamin function is not fully understood. Above all, ARC5, a dynamin-like protein, is important to chloroplast division, little is known about the functions of dynamin for division mechanism.
To understand the mechanism of chloroplast division by dynamin, we expressed several point mutants of ARC5 as a green fluorescence protein (GFP) fusion protein in under the control of ARC5 promoter. A mutant of GTPase domain localized as a ring at the division site of the chloroplast. However, the numbers of the chloroplasts in the cell of this plant was comparable to that of arc5 mutant, these results indicate that GTPase activity is essential for dynamin function but not for the localization at the division site. Analysis of other mutant proteins also will be discussed.
