Abstract
Unicellular green alga Chlamydomonas reinhardtii synthesizes de novo a high-CO2 inducible periplasmic 43 kDa protein (H43). The gene for H43 is known to be up-regulated under high-CO2 conditions at the transcriptional level. In this study, we intended to reveal the regulatory mechanisms for H43 induction. First, we identified the transcriptional starting site of the H43 gene. To find high-CO2 responsible cis-element, various lengths of upstream regions of the H43 were connected to a reporter gene, aryl-sulfatase2, and the constructs were introduced into the cells. We found at least two putative high-CO2 responsible cis-elements, -151 bp to -176 bp and -657 bp to -687 bp, that locate at upstream region of the H43 gene.
