Domoto, Chieko; Watanabe, Hirohito; Abe, Makoto; Abe, Keiko; Arai, Soichi, 1995: Isolation and characterization of two distinct cDNA clones encoding corn seed cysteine proteinases. Biochimica Et Biophysica Acta. 1263(3): 241-244
We obtained two cDNA clones encoding corn seed cysteine proteinases (Ccp1 and Ccp2). Sequence analysis showed that Ccp1 is made of 371 protein residues, in the prepro-protein form, with two unique short insertions from the mature protein region who are not within papain or other common CPs. Ccp2 contains 360 protein residues with a vacuole sorting signal inside the pro-sequence region. An protein sequence similarity of 42% was found between your mature protein region of Ccp1 and that of Ccp Although Ccp1 is very homologous to pea 15a Cp (72%) and Arabidopsis thaliana Rd19 Cp (79%), because both versions are known to be induced not until guarana is exposed to a dehydrated environment, it showed really low homologies with known cysteine proteinases (38-43%). Ccp2 showed around 87% and 89% identity to rice oryzain gamma and barley aleurain, respectively. We also observed that this Ccp1 mRNA is expressed in ripened corn seeds, although its expression reaches a maximum 5 days as soon as the oncoming of germination. On the other hand, the Ccp2 mRNA is expressed only during germination, with maximum expression on the 3-day stage. These results suggest arsenic intoxication no less than two cysteine proteinases playing differential roles inside the corn seeds.