The original goals of this project were the isolation of a rat thyroid hormone receptor cDNA in order to study the structure and function of the thyroid hormone receptor. The methodology as initially proposed involved the development of an anti-thyroid hormone receptor antibody for isolation of a rat thyroid hormone receptor cDNA from a cDNA library by epitope selection. New information has become available indicating that the cellular homolog of the avian erythroblastosis virus (v-erb-A) gene, c-erb- A, encodes a thyroid hormone receptor. By using synthetic peptides from the putative ligand-binding and DNA-binding domains of v-erb- A, a polyclonal anti-rat thyroid hormone receptor antibody has been developed. By using a v-erb-A hybridization probe, isolation of a rat thyroid hormone receptor cDNA(s) from a rat brain cDNA library has been carried through to the tertiary screening phase. In the next two years it is anticipated that the translation products of v-erb-A and c-erb-A (thyroid hormone receptor) will be studied in vitro in order to characterize their ligand-binding and DNA-binding properties. Transfection studies with both v-erb-A and c-erb-A are planned to document the functional expression of the translation products. Transient expression studies have been designed which will define the role of the v-erb-A and c-erb-A products in activating the thyroid hormone responsive promotor from the rat growth hormone gene, in transfected cells. A panel of variant receptor proteins will be generated by deletion/insertion mutagenesis and site-directed mutagenesis to more fully explore the structure/function relationship of thyroid hormone receptor.
| Horowitz, Z D; Yang, C R; Forman, B M et al. (1989) Characterization of the domain structure of chick c-erbA by deletion mutation: in vitro translation and cell transfection studies. Mol Endocrinol 3:148-56 |
| Samuels, H H; Forman, B M; Horowitz, Z D et al. (1989) Regulation of gene expression by thyroid hormone. Annu Rev Physiol 51:623-39 |
| Samuels, H H; Aranda, A; Casanova, J et al. (1988) Identification of the cis-acting elements and trans-acting factors that mediate cell-specific and thyroid hormone stimulation of growth hormone gene expression. Recent Prog Horm Res 44:53-114 |
| Horowitz, Z D; Sahnoun, H; Pascual, A et al. (1988) Analysis of photoaffinity label derivatives to probe thyroid hormone receptor in human fibroblasts, GH1 cells, and soluble receptor preparations. J Biol Chem 263:6636-42 |
| Samuels, H H; Forman, B M; Horowitz, Z D et al. (1988) Regulation of gene expression by thyroid hormone. J Clin Invest 81:957-67 |
