Submitted on September 14, 2007
Accepted on May 5, 2008
Transcription Factor PU.1 Is Expressed in White Adipose and Inhibits Adipocyte Differentiation
Fei Wang1 and Qiang Tong1*
1 Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas, United States
* To whom correspondence should be addressed. E-mail: qtong{at}bcm.edu.
PU.1 transcription factor is a critical regulator of hematopoiesis and leukemogenesis. Because PU.1 interacts with transcription factors GATA-2 and C/EBP
, and both are involved in the regulation of adipogenesis, we investigated whether PU.1 plays a role in the regulation of adipocyte differentiation. Our data indicate that PU.1 is expressed in white adipose tissue. PU.1 protein can also be detected in cultured 3T3-L1 adipocytes. Forced expression of PU.1 in 3T3-L1 cells inhibits adipocyte differentiation, while deletion of the transactivation domain of PU.1 abolishes this effect. The inhibition of adipocyte differentiation by PU.1 is achieved, at least in part, through repression of the transcriptional activity of C/EBP and C/EBP
. Furthermore, GATA-2 and PU.1 have an additive inhibitory effect on C/EBP transactivation and adipogenesis. Finally, the expression of PU.1 is increased in white adipose of obese mice.
