Molecular Endocrinology, Vol 9, 86-95, Copyright © 1995 by Endocrine Society

ARTICLES

The dominant negative effect of thyroid hormone receptor splicing variant alpha 2 does not require binding to a thyroid response element

RT Liu, S Suzuki, T Miyamoto, T Takeda, M Ozata and LJ DeGroot
Department of Medicine, University of Chicago, Illinois 60637, USA.

The functionally inactive thyroid hormone receptor splicing variant- alpha 2 (TRv alpha 2) can inhibit transcriptional activation by TR alpha 1 or beta 1, demonstrating a dominant negative effect (DNE). We examine here the three commonly proposed mechanisms, namely, competition for binding to thyroid hormone response elements (TREs), formation of inactive heterodimers, and squelching. A mutation introduced into the DNA-binding domain (DBD) of the TRv alpha 2 was designed to prevent its binding to TREs. In transient cotransfection studies, the DBD mutant has nearly the same DNE as does TRv alpha 2 on three different TRE-containing reporter genes. The DNE of TRv alpha 2 is also not reversed by cotransfection with excess retinoid X receptor- alpha. Extracts of COS cells cotransfected with TR alpha 1 and either TRv alpha 2 or DBD mutant at different ratios were analyzed by gel shift assays. Neither TRv alpha 2 or the mutant altered binding of TR alpha 1 to four radiolabeled TREs. TRv alpha 2 itself can inhibit constitutive transactivation by a thymidine kinase promoter-driven reporter construct. Our results suggest that TRv alpha 2 can function in a dominant negative manner without binding to a TRE, at least for certain TREs. It is concluded that the DNE of TRv alpha 2 may occur through another unrecognized mechanism, perhaps by binding to basal transcription factors.

This article has been cited by other articles:

				E. R. Nelson and H. R. Habibi Functional Significance of a Truncated Thyroid Receptor Subtype Lacking a Hormone-Binding Domain in Goldfish Endocrinology, September 1, 2008; 149(9): 4702 - 4709. [Abstract] [Full Text] [PDF]

				C R Liu, L Y Li, F Shi, X Y Zang, Y M Liu, Y Sun, and B H Kan Effects of hyper- and hypothyroid on expression of thyroid hormone receptor mRNA in rat myocardium J. Endocrinol., December 1, 2007; 195(3): 429 - 438. [Abstract] [Full Text] [PDF]

				J Kwakkel, W M Wiersinga, and A Boelen Interleukin-1{beta} modulates endogenous thyroid hormone receptor {alpha} gene transcription in liver cells J. Endocrinol., August 1, 2007; 194(2): 257 - 265. [Abstract] [Full Text] [PDF]

				L. Ng, A. Rusch, L. L. Amma, K. Nordstrom, L. C. Erway, B. Vennstrom, and D. Forrest Suppression of the deafness and thyroid dysfunction in Thrb-null mice by an independent mutation in the Thra thyroid hormone receptor {alpha} gene Hum. Mol. Genet., November 1, 2001; 10(23): 2701 - 2708. [Abstract] [Full Text] [PDF]

				C. Oberste-Berghaus, K. Zanger, K. Hashimoto, R. N. Cohen, A. N. Hollenberg, and F. E. Wondisford Thyroid Hormone-independent Interaction between the Thyroid Hormone Receptor beta 2 Amino Terminus and Coactivators J. Biol. Chem., January 21, 2000; 275(3): 1787 - 1792. [Abstract] [Full Text] [PDF]

				A. P. Farwell and S. A. Dubord-Tomasetti Thyroid Hormone Regulates the Extracellular Organization of Laminin on Astrocytes Endocrinology, November 1, 1999; 140(11): 5014 - 5021. [Abstract] [Full Text]

				A. P. Farwell and S. A. Dubord-Tomasetti Thyroid Hormone Regulates the Expression of Laminin in the Developing Rat Cerebellum Endocrinology, September 1, 1999; 140(9): 4221 - 4227. [Abstract] [Full Text]

				T. Tagami, P. Kopp, W. Johnson, O. K. Arseven, and J. L. Jameson The Thyroid Hormone Receptor Variant {alpha}2 Is a Weak Antagonist because It Is Deficient in Interactions with Nuclear Receptor Corepressors Endocrinology, May 1, 1998; 139(5): 2535 - 2544. [Abstract] [Full Text] [PDF]

				A. Farsetti, J. Lazar, M. Phyillaier, R. Lippoldt, A. Pontecorvi, and V. M. Nikodem Active Repression by Thyroid Hormone Receptor Splicing Variant {alpha}2 Requires Specific Regulatory Elements in the Context of Native Triiodothyronine-Regulated Gene Promoters Endocrinology, November 1, 1997; 138(11): 4705 - 4712. [Abstract] [Full Text] [PDF]

				M.-F. Langlois, K. Zanger, T. Monden, J. D. Safer, A. N. Hollenberg, and F. E. Wondisford A Unique Role of the beta -2 Thyroid Hormone Receptor Isoform in Negative Regulation by Thyroid Hormone. MAPPING OF A NOVEL AMINO-TERMINAL DOMAIN IMPORTANT FOR LIGAND-INDEPENDENT ACTIVATION J. Biol. Chem., October 3, 1997; 272(40): 24927 - 24933. [Abstract] [Full Text] [PDF]

				O. Chassande, A. Fraichard, K. Gauthier, F. Flamant, C. Legrand, P. Savatier, V. Laudet, and J. Samarut Identification of Transcripts Initiated from an Internal Promoter in the c-erbA{alpha} Locus That Encode Inhibitors of Retinoic Acid Receptor-{alpha} and Triiodothyronine Receptor Activities Mol. Endocrinol., August 1, 1997; 11(9): 1278 - 1290. [Abstract] [Full Text]

				M. J. Reginato, J. Zhang, and M. A. Lazar DNA-independent and DNA-dependent Mechanisms Regulate the Differential Heterodimerization of the Isoforms of the Thyroid Hormone Receptor with Retinoid X Receptor J. Biol. Chem., November 8, 1996; 271(45): 28199 - 28205. [Abstract] [Full Text] [PDF]

				Y.-Z. Yang, M. Burgos-Trinidad, Y. Wu, and R. J. Koenig Thyroid Hormone Receptor Variant alpha 2. ROLE OF THE NINTH HEPTAD IN DNA BINDING, HETERODIMERIZATION WITH RETINOID X RECEPTORS, AND DOMINANT NEGATIVE ACTIVITY J. Biol. Chem., November 8, 1996; 271(45): 28235 - 28242. [Abstract] [Full Text] [PDF]

				P. M. Yen, Y. Liu, A. Sugawara, and W. W. Chin Vitamin D Receptors Repress Basal Transcription and Exert Dominant Negative Activity on Triiodothyronine-mediated Transcriptional Activity J. Biol. Chem., May 3, 1996; 271(18): 10910 - 10916. [Abstract] [Full Text] [PDF]