| First Author | Valverde RA | Year | 2001 |
| Journal | Mol Cell Endocrinol | Volume | 173 |
| Issue | 1-2 | Pages | 29-40 |
| PubMed ID | 11223175 | Mgi Jnum | J:68001 |
| Mgi Id | MGI:1931914 | Doi | 10.1016/s0303-7207(00)00437-8 |
| Citation | Valverde RA, et al. (2001) Biochemical characterization and expression analysis of the Xenopus laevis corticotropin-releasing hormone binding protein. Mol Cell Endocrinol 173(1-2):29-40 |
| abstractText | Corticotropin-releasing hormone (CRH) plays a key role in the regulation of responses to stress. The presence of a high affinity binding protein for CRH (CRH-BP) has been reported in mammals. We have characterized the biochemical properties and expression of CRH-BP in the South African clawed frog, Xenopus laevis. Apparent inhibition constants (K(i[app])) for different ligands were determined by competitive binding assay. Xenopus CRH-BP (xCRH-BP) exhibited a high affinity for xCRH (K(i[app])=1.08 nM) and sauvagine (1.36 nM). Similar to rodent and human CRH-BPs, the frog protein binds urotensin I and urocortin with high affinity, and ovine CRH with low affinity. RT-PCR analysis showed that xCRH-BP is expressed in brain, pituitary, liver, tail, and intestine. Brain xCRH-BP mRNA is expressed at a relatively constant level throughout metamorphosis and increases slightly in the metamorphic frog. By contrast, the gene is strongly upregulated in the tail at metamorphic climax. Thus, regulation of xCRH-BP gene expression is tissue specific. Because xCRH-BP binds CRH-like peptides with high affinity the protein may regulated, the bioavailability of CRH in amphibia as it does in mammals. |
