Repression of CD2 gene expression is mediated by an AP-2 related factor

Tissue specific and developmental expression of the CD2 gene is tightly reg ulated during T cell development. DNase I hypersensitivity analysis has rev ealed the presence of two sites (DHS1 and 2) located 5' to the CD2 gene whi ch have been reported to be implicated in the developmental regulation of e xpression of CD2, The location of DHS2 marks the position of the minimal pr omoter whereas DHS1 is located approximately 1800 bp upstream. We show that repressor and derepressor activities are contained within the region of DN A marked by DHS1, The repressor is capable of regulating homologous and het erologous promoters regardless of orientation. This activity is entirely de pendent upon the presence of an AP-2 binding site as mutation of this site resulted in a loss of repressor activity. A nuclear factor found in Jurkat cells specifically binds this site but was shown to be serologically distin ct from AP-2. (C) 2001 Academic Press.