DISTINCT DISTAL AND PROXIMAL P53-BINDING SITES IN THE MCK PROMOTER GOVERN THE TRANSCRIPTIONAL RESPONSE TO P53

We have investigated the functional importance of nucleotide sequence differences between proximal (P-) and distal (D-) p53-binding elements in the MCK promoter, P- and D-elements normally co-operate to permit synergistic promoter activation by p53. Interestingly, we find that P- elements cannot co-operate with each other, In contrast, co-operation between D-binding sites results in levels of p53-induced transcription far higher than those obtained by co-operation between P- and D-eleme nts, These studies imply that distinct D- and P-p53-binding sites in t he MCK promoter may dictate the promoter response to p53. (C) 1997 Fed eration of European Biochemical Societies.