PPARγ knockdown by engineered transcription factors: exogenous PPARγ2 but not PPARγ1 reactivates adipogenesis

  1. Delin Ren1,
  2. Trevor N. Collingwood2,
  3. Edward J. Rebar2,
  4. Alan P. Wolffe2, and
  5. Heidi S. Camp1,3
  1. 1Department of Molecular Science and Technology, Pfizer Global and Research Development, Ann Arbor, Michigan 48105, USA; 2Sangamo BioSciences Inc., Pt. Richmond, California 94804, USA

Abstract

To determine functional differences between the two splice variants of PPARγ (γ1 and γ2), we sought to selectively repress γ2 expression by targeting engineered zinc finger repressor proteins (ZFPs) to the γ2-specific promoter, P2. In 3T3-L1 cells, expression of ZFP55 resulted in >50% reduction in γ2 expression but had no effect on γ1, whereas adipogenesis was similarly reduced by 50%. However, ZFP54 virtually abolished both γ2 and γ1 expression, and completely blocked adipogenesis. Overexpression of exogenous γ2 in the ZFP54-expressing cells completely restored adipogenesis, whereas overexpression of γ1 had no effect. This finding clearly identifies a unique role for the PPARγ2 isoform.

Keywords

Footnotes

  • 3 Corresponding author.

  • E-MAIL heidi.camp{at}pfizer.com; FAX (734) 622-5668.

  • Article and publication are at http://www.genesdev.org/cgi/doi/10.1101/gad.953802.

    • Received October 12, 2001.
    • Accepted November 15, 2001.
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