Abstract
A novel cDNA clone (OsNInv) encoding a neutral invertase was isolated from rice. The deduced amino acid sequence of the OsNInv cDNA clone showed high similarity to other plant alkaline/neutral invertases. Semi-quantitative RT-PCR revealed that the level of OsNInv expression was quite low and the pattern of its expression was not organ specific. Analyses using three types of web software for the prediction of protein localization in the cell, Predotar, TargetP, and PSORT, strongly supported the possibility that OsNInv is transported into the mitochondria. Transient expression of a fusion protein combining the amino terminal region of OsNInv with sGFP demonstrated that the N-OsNInv::GFP fusion protein was transported into the mitochondria efficiently. The results of this study revealed that the amino terminal region of OsNInv possesses the mitochondrial targeting signal and suggested that OsNInv protein is accumulated in the mitochondria.
