Purification and identification of positive regulators binding to a novel element in the c-Jun promoter.

ABSTRACT: A putative response element, GAGCCTC, was observed years ago in footprinting analysis of the c-jun promoter, and here we investigate its function in regulating c-jun expression and identify a protein complex that binds there. Electrophoretic mobility shift assays demonstrate a sequence-specific binding complex with this element in HEK293 cells. Additionally, unlabeled consensus AP-1 element DNA, but not a similar NF-jun element DNA, competes with complex formation. Mutations of this element decrease c-jun promoter reporter activity by nearly 5-fold in HEK293 cells. A new, two-step oligonucleotide trapping technique was developed to purify the element binding proteins. LC-nanospray-ESI-MS/MS identification and Western blotting show that the purified complex contains Ku80 and c-jun, which wa

SUBMITTER: Jiang D 

PROVIDER: S-EPMC2905795 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature