Abstract
In higher plants, the genes related to the maintenance of the mitochondrial morphology are still largely unknown. In the present study, a rice dynamin-like protein, OsDRP3A, was identified as a rice homologue of Arabidopsis DRP3A and DRP3B proteins, which are involved in mitochondrial fission. Transient expression of a dominant-negative mutant of OsDRP3A containing the amino acid point mutation (K63A), caused mitochondria to become larger and less numerous than those in the native variety. A protein resulting from the fusion of green fluorescent protein (GFP) and wild-type OsDRP3A was observed, appearing in the form of punctate structures located at the tips and the constriction sites of mitochondria in live tobacco suspension-cultured (BY-2) cells. On the other hand, when GFP was fused to the dominant-negative mutant OsDRP3A (K63A), the mitochondrial morphology was distorted. These results suggest that OsDRP3A is involved in mitochondrial fission.
