Molecular cloning and characterization of the human p44 mitogen-activated protein kinase gene.

The complete genomic structure of the human p44(mapk) gene (HMGW-approved symbol PRKM3) has been determined. The gene covers 9 kb and is composed of nine exons and eight introns. This structure is identical to the previously reported mouse p44(mapk) gene, indicating a high degree of evolutionary conservation. A sequence differing by one nucleotide from the consensus TATA box is present 132 positions upstream of the main transcription initiation point. This point has been located 415 nucleotides upstream of the translation initiation codon ATG and perfectly meets the consensus criteria for an initiator element (Inr). Multiple consensus sequences for factors that regulate either basal transcription or gene expression during cell differentiation and proliferation can be found in the putative promoter region. Some of them, such as several G/C boxes located downstream from the transcription initiation point, are also present in the homologous mouse gene, where they were shown to be functional.