抄録
We previously isolated a cDNA encoding a large GTP-binding protein (mOPA1) from the mouse brain, and observed that mOPA1 is localized to mitochondria and its expression induced the mitochondrial fragmentation in transfected cultured cells. By probing mouse brain extracts on SDS-PAGE with two kinds of anti-mOPA1 antibodies that recognize the C-terminal region of mOPA1, we detected two bands of approximately 90 and 80 kDa. Highly similar results were observed for COS-7 or HEK293T cells transfected with wild type mOPA1. Since their sizes were obviously smaller than the estimated molecular weight (111 kDa) of mOPA1, a possibility of intracellular processing was suggested. Judging from the band size of N-terminal deletion mutants, mOPA1 was showed to cleave at the N-terminal region near 100 or 200 residues. We aimed to determine the cleavage positions and analyzed the processing pattern of various point mutants and deletion mutants of mOPA1. Both 90 kDa and 80 kDa bands almost completely disappeared by R101S point mutation or by T191-A195 deletion, respectively. These results show that intracellular processing of the mOPA1 protein occur at two positions near R101 and T191 residues, producing 90 and 80 kDa forms. [Jpn J Physiol 55 Suppl:S71 (2005)]
