Molecular analysis of the cDNA and genomic DNA encoding mouse RNA helicase A

RNA helicase A is an enzyme that possesses both RNA and DNA helicase activities. In this report, we describe the isolation of a mouse cDNA encoding RNA helicase A. The deduced amino acid sequence derived from mouse RNA helicase A cDNA exhibits 87 and 47% identity to its human and Drosophila homologs, respectively. Using Southern blot analysis employing a mouse backcross panel, we have assigned the mouse RNA helicase A gene to chromosome 1, mapping near the D1Bir20 locus at MGD position 67. Northern blot and primer extension analyses indicate that, although its level is variable, RNA helicase A appears to be expressed from a single transcription start site in all tissues tested. Sequence analysis of the upstream genomic DNA revealed that the promoter region lacks a TATA box and contains two high-affinity sites for Sp1, one ISRE, a binding site for interferon regulatory factor, and three AP2-binding sites. These findings suggest that the transcriptional regulation of the RNA helicase A gene is complex.