CHARACTERIZATION OF THE MURINE CDC2 GENE

A 1204 bp full-length cDNA encoding murine cdc2 was isolated and used as a probe to obtain four overlapping cdc2 genomic clones which span the entire cdc2 sequence. Characterization of these clones revealed that the cdc2 mRNA is distributed over 28 kb and in 8 exons ranging in size from 63 to approximately 303 bp. Since the 5'-untranslated sequence is interrupted by intron 1, the initiation codon is located in exon 2. The PSTAIRE region is in exon 3, and the stop codon is in exon 8. Primer extension analysis of cdc2 mRNA isolated from immobilized anti-CD3 activated T-cells demonstrated that the murine cdc2 gene utilizes multiple transcriptional start sites. No consensus sequence for a TATA box exists at an appropriate position within the promoter region. Instead, several putative transcription factor binding sites for PEA3, CREB, C/EBP, E box factor, YY1, ATF-like, Spl, and E2F were detected. Analysis of the promoter activity of the 5'-flanking region suggests that the sequence between -188 to -38, which possesses two Spl and one E2F motif, contains a major positive regulatory activity for the expression of murine cdc2.