A dominant negative PPARγ mutant shows altered cofactor recruitment and inhibits adipogenesis in 3T3-L1 cells

Y. Park, B. D. Freedman, Eunjig Lee, S. Park, J. L. Jameson

Research output: Contribution to journalArticle

35 Citations (Scopus)

Abstract

Aims/hypothesis. PPARγ, a member of the nuclear hormone receptor family of transcription factors, plays a key role in adipocyte differentiation and insulin sensitivity. The aim of this study was to identify a potential dominant negative murine PPARγ mutant and to characterize the in vitro functional properties of this mutant. Methods. In vitro transient transfections and mammalian two-hybrid assays in TSA201 cells were used to characterize the transcriptional activity of the L466A mutant and to study the molecular interaction of transcriptional cofactors with the L466A mutant in an attempt to elucidate the mechanism of its dominant negative activity. Adenoviral constructs expressing PPARγ wild-type (AdWT) or the L466A mutant (AdL466A) were infected into the murine 3T3-L1 cell line to study the mutant's effect on adipogenesis. Results. The L466A mutant alone is transcriptionally defective. However, it retains DNA binding and inhibits the ligand-dependent and -independent activity of the wild-type receptor, consistent with dominant negative properties. In mammalian two-hybrid studies, the L466A mutant does not bind nuclear receptor coactivators. However, it more avidly recruits corepressors due to enhanced binding to the corepressor ID1 domain, leading to pronounced transcriptional repression. The AdL466A mutant inhibits adipogenesis induced by either a differentiation cocktail or by thiazolidinedione ligand. AdL466A infection also blocked the upregulation of the adipocyte marker genes aP2 and adipsin. Conclusion. We conclude that the L466A PPARγ mutant possesses potent dominant negative activity based on preferential corepressor recruitment and it inhibits adipogenesis and the expression of adipocyte-specific genes.

Original languageEnglish
Pages (from-to)365-377
Number of pages13
JournalDiabetologia
Volume46
Issue number3
DOIs
Publication statusPublished - 2003 Mar 1

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3T3-L1 Cells
Adipogenesis
Peroxisome Proliferator-Activated Receptors
Co-Repressor Proteins
Adipocytes
Nuclear Receptor Coactivators
Complement Factor D
Ligands
Two-Hybrid System Techniques
Cytoplasmic and Nuclear Receptors
Genes
Transfection
Insulin Resistance
Transcription Factors
Up-Regulation
Cell Line
DNA
Infection
In Vitro Techniques

All Science Journal Classification (ASJC) codes

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism

Cite this

Park, Y. ; Freedman, B. D. ; Lee, Eunjig ; Park, S. ; Jameson, J. L. / A dominant negative PPARγ mutant shows altered cofactor recruitment and inhibits adipogenesis in 3T3-L1 cells. In: Diabetologia. 2003 ; Vol. 46, No. 3. pp. 365-377.
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A dominant negative PPARγ mutant shows altered cofactor recruitment and inhibits adipogenesis in 3T3-L1 cells. / Park, Y.; Freedman, B. D.; Lee, Eunjig; Park, S.; Jameson, J. L.

In: Diabetologia, Vol. 46, No. 3, 01.03.2003, p. 365-377.

Research output: Contribution to journalArticle

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