EXPRESSION SCREENING REVEALS AN ORPHAN RECEPTOR CHICK OVALBUMIN UPSTREAM PROMOTER TRANSCRIPTION FACTOR-I AS A REGULATOR OF NEURITE SUBSTRATE-CELL CONTACTS AND CELL-AGGREGATION

A rat homologue of chick ovalbumin upstream promoter transcription fac tor I (COUP-TF I) was isolated using an expression cloning method deve loped to isolate neurite outgrowth inhibitors. Overexpression of COUP- TF I in 3T3 fibroblasts resulted in reduction of stable contact format ion between neurites and transfected cells. Additionally, COUP-TF I en hanced retinoic acid response element-dependent reporter gene expressi on in 3T3 fibroblasts, indicating that COUP-TF I can modulate transcri ptional activation in these cells. Our data suggest that COUP-TF trans cription factors are involved in the regulation of cell surface molecu les during neurogenesis.