화학공학소재연구정보센터
Biochemical and Biophysical Research Communications, Vol.288, No.4, 752-756, 2001
Downregulation of repressive CUP/AP-2 isoforms during adipocyte differentiation
Activation of transcription of the C/EBP alpha (CCAAT/enhancer binding protein a) gene is a critical event in the differentiation of 3T3-L1 preadipocytes into adipocytes. The kinetics of this process parallels a decline of AP-2 alpha protein (also referred to as CUP, C/EBP undifferentiated protein) and decreased binding of CUP/AP-2 alpha to the C/EBP alpha promoter. Mutation of the CUP/AP-2 binding sites in the C/EBPa promoter results in increased C/EBPa expression. Based on these findings, it appears that decline in AP-2a expression is an important early event in the adipocyte differentiation program. In the studies presented here, we identify three mRNAs that encode the repressive CLTP/AP-2 alpha isoforms expressed in undifferentiated 3T3-L1 preadipocytes. We demonstrate that the kinetics of the decline of these isoforms' expression over the course of differentiation parallels both the decrease in CUP/AP-2 alpha DNA binding activity and the increase in C/EBP alpha protein observed in previous studies.