Abstract
Most of proteins functioning in organelle are encoded by nuclear genes. It is accepted that these genes were translocated from the endsymbiotic bacteria and acquired organelle targeting sequence. However the acquiring process is unknown.
We previously reported that genomes of several species have cryptic organelle targeting sequences (Annual Meeting of JSPP, 2007). In addition, it was reported that a coding sequence for a transit peptide of the certain gene was derived from a frameshifted sequence of an unrelated gene (Ueda et. al.,2006). This is an example where cryptic sequence was actually utilized. To gain an organelle targeting sequence, transferred genes must be introduced in the downstream of it. We propose a hypothesis that the translational initiation mechanism of eukaryote, which is different from that of prokaryote, lead to use of cryptic organelle targeting sequences.
