Insulin-like growth factor binding protein-3 interacts with the thyroid hormone receptor α1 and modulates transcription of thyroid hormone responsive gene.
- Author:
Qiu JIA
1
;
Ma XIAO-LI
;
Wang XIN
;
Chen HONG
;
Huang BING-REN
Author Information
- Publication Type:Journal Article
- MeSH: HEK293 Cells; Humans; Insulin-Like Growth Factor Binding Protein 3; metabolism; Promoter Regions, Genetic; Thyroid Hormone Receptors alpha; metabolism; Thyroid Hormones; genetics; metabolism; Transcription, Genetic; Triiodothyronine; pharmacology
- From: Acta Academiae Medicinae Sinicae 2011;33(2):156-161
- CountryChina
- Language:English
-
Abstract:
OBJECTIVETo study the interaction between insulin-like growth factor binding protein-3 (IGFBP-3) and thyroid hormone receptor α1 (TRα1) and the modulatory effect of IGFBP-3 on transcription of the thyroid hormone responsive gene.
METHODSThe interaction between IGFBP-3 and TRα1 was detected with glutathione-S-transferase pull-down method, co-immunoprecipitation, fluorescence resonance energy transfer test. The cellular distribution of these two proteins was observed by confocal laser scanning microscopy. The effect of IGFBP-3 on the growth hormone promoter activity stimulated by triiodothyronine (T3) was determined by dual-luciferase reporter assay.
RESULTSIGFBP-3 interacted with TRα1 both in vivo and in vitro. IGFBP-3 and TRα1 were shown to co-localize in the nucleus of HEK-293 cells. The overexpressed IGFBP-3 inhibited the growth hormone promoter activity stimulated by T3 (P<0.01).
CONCLUSIONSIGFBP-3 interacts with TRα1 and inhibits T3 responsive gene transcription. This finding further confirms the insulin-like growth factor-independent role of IGFBP-3 in the nucleus.
