Abstract
Cyanidium caldarium is a unicellular primitive red alga which grows in acidic environments (pH 1-3), but cannot survive above pH 7. In our previous study, we found that a large amount of only one protein was secreted from C. caldarium when the alga was cultured at pH 6. This protein showed relative high homology with lysyl oxidase (LOX), which found in animal cells but not in plant cells. Therefore ,we named it lysyl oxidase like protein (LOL). In this study, we examined pH dependence of the secreted amount of LOL protein, and found that a slight amount of LOL was secreted even at acidic pH. The similar gene of LOL protein was found in another acidophilic primitive red alga. Thus, we examined the secretion of LOL protein from C. melorae cells, but the protein was not secreted. There is no information about the localization and function of LOL protein. Thus, we prepared an antibody against LOL protein to elucidate the localization of LOL protein, and found that a large amount of LOL protein was also presented in intracellular fractions. We will discuss the localization and function of LOL protein.
