Transcription factor-induced, phased bending of the E-selectin promoter.

E-selectin is an endothelial adhesion molecule that is critically involved in neutrophil adhesion and recruitment. All DNA elements required for interleukin-1 inducibility have been located in the proximal promoter: an NF-ELAM1/ATF site, two NF-kappa B sites (I and II), the NF-ELAM2 element and a TATA box. We show here that interleukin-1 induced promoter activity is exquisitely sensitive to the spatial arrangements of these elements. Phasing of the ATF and NF-kappa B II elements indicates that their relative helix orientation is more important than distance per se. This sensitivity is partly due to a requirement for correctly oriented, transcription factor-induced DNA-bending. (i) Band shift analyses with permuted ATF- and NF-kappa B elements show that their associated factors all bend DNA. (ii) One can functionally replace the NF-ELAM1/ATF element by a subset of a panel of DNA fragments that contain defined bends in various planes. We conclude that the main role of the factors binding at the NF-ELAM1/ATF element is to alter the conformation of the E-selectin promoter, presumably looping distant enhancer elements into each other's proximity.