Cloning and characterization of Xenopus dicalcin, a novel S100-like calcium-binding protein in Xenopus eggs

Abstract

To contribute to the study of the calcium-signaling mechanism of egg, we cloned and characterized a 26 kDa Ca^{2 +} -binding protein from Xenopus laevis eggs, a homologue of Rana catesbeiana dicalcin (renamed from p26olf) that was isolated from the olfactory epithelium. The primary structure of Xenopus dicalcin shows ∼61% identity to that of Rana dicalcin and consists of two S100-like regions aligned in tandem, as seen in Rana dicalcin. Genomic Southern blot analysis indicated that Xenopus dicalcin is a unique orthologue of Rana dicalcin. Northern blot analysis showed that Xenopus dicalcin mRNA is expressed in Xenopus eggs and also in other tissues. These results indicated that Xenopus dicalcin is a novel S100-like Ca^{2 +} -binding protein in Xenopus eggs.

• Xenopus laevis
• egg
• dicalcin
• calcium-binding protein
• S100

• AB063625

Acknowledgements

The Xenopus egg cDNA library was generously provided from Prof. Takisawa at Osaka University. This work was supported by a Grant-in-Aid (13780636) from the JSPS to N.M., and Research for the Future Program of the JSPS under the Project “Cell Signaling” (JSPS-RFTF97L00301) to S.K.