Translator Disclaimer
1 February 2012 Binding Properties of Thyroxine to Nuclear Extract from Sea Urchin Larvae
Minoru Saito, Kyo Yamasu, Takashi Suyemitsu
Author Affiliations +

We previously reported that thyroid hormones are involved in the formation of the adult rudiment and adult-type skeleton in sea urchin larvae, as well as in the resorption of larval tissues. In the present study, to search for the presence of thyroid hormone receptor in sea urchin larvae, we performed a ligand-binding assay between radiolabeled thyroid hormones and nuclear extracts from the larvae of the sea urchin Hemicentrotus pulcherrimus. The presence of binding sites with a high affinity to thyroxine (T4) was detected in the nuclear extract, but not in the cytoplasmic fraction. The dissociation constants for the T4 binding to the nuclear extracts were estimated to be about 18 pM from the mesenchyme-blastula stage to the four-armed pluteus stage. The quantity of T4 binding sites in the nuclear extracts increased during larval development. These results suggest that the binding affinity to T4 in the nuclear extracts was caused by a putative nuclear thyroid hormone receptor in sea urchin larvae.

© 2012 Zoological Society of Japan
Minoru Saito, Kyo Yamasu, and Takashi Suyemitsu "Binding Properties of Thyroxine to Nuclear Extract from Sea Urchin Larvae," Zoological Science 29(2), 79-82, (1 February 2012).
Received: 11 May 2011; Accepted: 1 August 2011; Published: 1 February 2012

dissociation constant
sea urchin
thyroid hormone
thyroid hormone receptor
Get copyright permission
Back to Top