A CDNA CLONING OF HUMAN AEBP1 FROM PRIMARY CULTURED OSTEOBLASTS AND ITS EXPRESSION IN A DIFFERENTIATING OSTEOBLASTIC CELL-LINE

By comparing lists of 3'-directed partial cDNA sequences (gene signatu res) randomly collected from various tissues, genes uniquely expressed in individual tissue can be identified. A full length cDNA clone, cor responding to one such gene signature, unique to human osteoblast and adipose tissue, was isolated. This cDNA clone encodes a 845-amino acid protein that is almost identical to the mouse adipocyte transcription factor AEBP1 except that it has additional 105 amino acids in the N t erminus. A northern hybridization showed that in the differentiating m urine osteoblastic cell line, AEBP1 is also expressed but that it is s hut off in the final calcification phase, suggesting a transcriptional repressive effect on genes for bone formation. (C) 1996 Academic Pres s, Inc.