Thyroid hormone receptor alpha(1) regulates expression of the na+/H+ exchanger (NHE1)

• Author(s) / Creator(s)

  • Li, Xiuju J.
  • Misik, Angelika J.
  • Rieder, Carmen V.
  • Solaro, R. John
  • Lowen, Anice
  • Fliegel, Larry

• In this paper we examine the role of thyroid hormone in regulating expression of the Na+/H+ exchanger. Thyroid hormone has been reported to regulate the activity of the Na+/H+ exchanger messenger RNA in some cell types. Treatment of cardiac myocytes with 3,5′,3′-triiodothyronine results in an increased expression of Na+/H+exchanger protein. Also, compared with euthyroid animals, hypothyroid rats express decreased amounts of the Na+/H+exchanger protein. To examine the mechanisms involved in regulating expression of the Na+/H+ exchanger, we have characterized the regulation of a distal element of the NHE1 promoter by the thyroid hormone receptor. We have previously shown that a −1085/−800 nucleotide (nt) region of the promoter is a modular element with a −841/−800 nt activating element. Using electrophoretic mobility shift assay, we show that this element interacts with thyroid hormone receptor TRα1, a nuclear hormone receptor. The addition of exogenous TRα increased transcriptional activity of the −841/−800 nt element of the Na+/H+ exchanger promoter. We show that TRα binds to a region on the −841/−800 nt element that is near, but not identical, to the previously identified chicken ovalbumin upstream promoter transcription factor-binding site. Our results are the first demonstration that thyroid hormone and the thyroid hormone receptor TRα1 regulate expression of the Na+/H+ exchanger.

• Date created

  2002-01-01

• Subjects / Keywords

  • Rat Myocardium
  • Acid
  • Gene
  • Activation
  • Heart-Failure
  • Transcription Factor
  • Na/H Antiporter
  • Protein
  • Responsive Element
  • Messenger-RNA

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/r3-05w5-j243

• License

  Attribution 4.0 International