IDENTIFICATION AND CHARACTERIZATION OF THE HUMAN ADIPOCYTE APM-1 PROMOTER

The human adipocyte-specific apM-1 gene encodes a secretory protein of the adipose tissue and seems to play a role in the pathogenesis of ob esity. A 1.3 kb amount of the proximal promoter region has been cloned and analyzed for the presence of putative transcription factor bindin g sites. Several binding sites known to be involved in adipogenesis an d regulation of adipocyte-specific genes (C/EBP, SREBP) are present. N o TATA box, but a classical CCAAT box could be identified. To confirm functionality and cell specificity of the 1.3 kb promoter, a series of 5'-deleted fragments were ligated in front of the luciferase gene and the constructs were transfected into 3T3-L1 adipocytes. The reporter gene was effectively transcribed, as demonstrated by the expression of enzyme activity. The 5'-end of the human cDNA was completed by 5'-RAC E-PCR. Several alternative transcription start sites were detected by RNase protection assay and primer extension analysis. In addition, an exon/intron boundary was mapped at the extreme 5'-end of the cDNA sequ ence. Genomic Southern blotting suggests that the human apM-1 gene is a single copy gene. (C) 1998 Elsevier Science B.V. All rights reserved .