"Functional Interaction between TATA and Upstream CACGTG Elements Regulates the Temporally Specific Expression of Otx mRNAs during Early Embryogenesis of the Sea Urchin, Hemicentrotus pulcherrimus".
Akiko Kobayashi, Koji Akasaka 1, Masashi Kawaichi and Tetsuro Kokubo 2, *
Division of Gene Function in Animals, Nara Institute of Science and
Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan,
1 Department of Mathematical and Life Sciences, Graduate
School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8511,
Japan and
2 Division of Molecular and Cellular Biology, Science
of Biological Supramolecular Systems, Graduate School of Integrated Science,
Yokohama City University, 1-7-29, Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa
230-0045, Japan
*To whom correspondence should be addressed. Tel: +81 45 508 7237;
Fax: +81 45 508 7369;
Email: kokubo@tsurumi.yokohama-cu.ac.jp
The orthodenticle-related protein (HpOtx) gene derived from the sea
urchin Hemicentrotus pulcherrimus encodes two distinct isoforms,
HpOtxE and HpOtxL, which are differentially expressed during early embryogenesis
and are driven by TATA-less and TATA-containing promoters, respectively.
In order to determine if the TATA element is involved in the establishment
of the temporally specific expression profile of the HpOtx gene, reporter
genes under the control of modified or wild-type HpOtxE/L promoters were
introduced into fertilized eggs. When the activities of the different promoter
constructs were examined, we found that deletion of the TATA element from
the HpOtxL promoter causes early expression, whereas addition of the TATA
element to the HpOtxE promoter causes delayed expression. This suppressive
action of the TATA
element on transcription from the HpOtxE/L promoters requires the
presence of upstream CACGTG elements. These results indicate that the presence
or absence of the TATA element determines, at least in part, the expression
profile of the HpOtxE/L promoters, in concert with the transcription factor(s)
that binds to the upstream CACGTG element. Immunoblot and gel retardation
analyses suggest that functional interaction between CACGTG binding factor(s)
and TATA factor(s) may be regulated by an unidentified third factor(s)
during early embryogenesis in the sea urchin.
1. Herstein PR, and Frenster JH, "Mated Models of Gene Regulation in Eukaryotes".
2. Frenster JH, "Ultrastructural Probes of Active
DNA Sites, and the RNA Activators of DNA".