Nuclear cytoplasmic shuttling by thyroid hormone receptors. multiple protein interactions are required for nuclear retention.

Published

Journal Article

In this report, we have studied the intracellular dynamics and distribution of the thyroid hormone receptor-beta (TRbeta) in living cells, utilizing fusions to the green fluorescent protein. Wild-type TRbeta was mostly nuclear in both the absence and presence of triiodothyronine; however, triiodothyronine induced a nuclear reorganization of TRbeta. By mutating defined regions of TRbeta, we found that both nuclear corepressor and retinoid X receptor are involved in maintaining the unliganded receptor within the nucleus. A TRbeta mutant defective in DNA binding had only a slightly altered nuclear/cytoplasmic distribution compared with wild-type TRbeta; thus, site-specific DNA binding is not essential for maintaining TRbeta within the nucleus. Both ATP depletion studies and heterokaryon analysis demonstrated that TRbeta rapidly shuttles between the nuclear and the cytoplasmic compartments. Cotransfection of nuclear corepressor and retinoid X receptor markedly decreased the shuttling by maintaining unliganded TRbeta within the nucleus. In summary, our findings demonstrate that TRbeta rapidly shuttles between the nucleus and the cytoplasm and that protein-protein interactions of TRbeta with various cofactors, rather than specific DNA interactions, play the predominant role in determining the intracellular distribution of the receptor.

Full Text

Duke Authors

Cited Authors

  • Baumann, CT; Maruvada, P; Hager, GL; Yen, PM

Published Date

  • April 6, 2001

Published In

Volume / Issue

  • 276 / 14

Start / End Page

  • 11237 - 11245

PubMed ID

  • 11152480

Pubmed Central ID

  • 11152480

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.M011112200

Language

  • eng

Conference Location

  • United States