PPARgamma knockdown by engineered transcription factors: exogenous PPARgamma2 but not PPARgamma1 reactivates adipogenesis.
To determine functional differences between the two splice variants of PPARgamma (gamma1 and gamma2), we sought to selectively repress gamma2 expression by targeting engineered zinc finger repressor proteins (ZFPs) to the gamma2-specific promoter, P2. In 3T3-L1 cells, expression of ZFP55 resulted in >50% reduction in gamma2 expression but had no effect on gamma1, whereas adipogenesis was similarly reduced by 50%. However, ZFP54 virtually abolished both gamma2 and gamma1 expression, and completely blocked adipogenesis. Overexpression of exogenous gamma2 in the ZFP54-expressing cells completely restored adipogenesis, whereas overexpression of gamma1 had no effect. This finding clearly identifies a unique role for the PPARgamma2 isoform.
Ren
Delin
D
Department of Molecular Science and Technology, Pfizer Global and Research Development, Ann Arbor, Michigan 48105, USA.
Collingwood
Trevor N
TN
Rebar
Edward J
EJ
Wolffe
Alan P
AP
Camp
Heidi S
HS
D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000502:physiology*; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology; D051379:Mice; D020033:Protein Isoforms / Q000235:genetics; D012326:RNA Splicing; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D016335:Zinc Fingers
D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors