Analysis of intron 4 of the p53 gene in human cutaneous melanoma.

DNA sequencing of intron 4 of the p53 gene from seven cutaneous melanoma cell lines showed an absence of mutations. However, both control and melanoma cell lines sequences were different from the reference source obtained from GenBank databank (accession No. X54156). Base pairs 101 and 689 were determined to be T (instead of A) and C (instead of G). Also, an additional C was not detected at position 371. Comparative analysis with p53 DNA-binding sequences, a sequence recognized by a p53 intron 4-binding protein and consensus sequences recognized by transcription factors demonstrated that intron 4 contains putative sequences for NF-kappa B, SP1, AP1 and TFIID binding. Binding of transcription factors could be one of the mechanisms by which intron 4 modulates human p53 expression.