Fig 7.
The p19ink4d proximal promoter region is a direct target of Msx1. (A) After chromatin immunoprecipitation, samples from C3H10T1/2 cells transfected with pCMV-Msx1-FLAG were PCR amplified; the binding region was directly amplified prior to immunoprecipitation (1% Input) and specifically amplified in the immunoprecipitated sample (anti-FLAG). No amplification was detected in the nonspecific IgG (normal mouse serum IgG)-immunoprecipitated sample (IgG) due to low background under the exogenous overexpression of Msx1 in cells. (B) After chromatin immunoprecipitation, samples from untransfected C3H10T1/2 cells were PCR amplified; the binding region was directly amplified prior to immunoprecipitation (1% Input) and specifically amplified in the immunoprecipitated sample (anti-Msx1). (C and D) Quantitative analysis of Msx1 binding preference from transfected cells (exogenous expression) (C) and untransfected cells (endogenous expression) (D). In both situations, there was a 3-fold-higher preference of Msx1 for binding site 2 (nt 1190) over binding site 1 (nt 1464) in vivo. M, DNA marker.