THE GENE STRUCTURE AND PROMOTER SEQUENCE OF MOUSE HYALURONAN SYNTHASE-1 (MHAS1)

The structure and organization of mouse hyaluronan synthase 1 gene, HA S1 were determined by direct sequencing of lambda phage clones carryin g the entire gene and by application of the long and accurate (LA)-PCR method to amplify regions encompassing the exon-intron boundaries and all of the exons. This gene spans about 11 kb of genomic DNA and cons ists of 5 exons and 4 introns. A similarity in the exon-intron organiz ation was found between the genes of mouse HAS1 and Xenopus laevis DG4 2 which was recently identified as Xenopus hyaluronan synthase. The tr anscription initiation site was determined by rapid amplification of t he cDNA ends (5'-RACE). Position +1 is located 55 nucleotides upstream of the ATG initiation codon. The promoter region of the HASI gene has no typical TATA box, but contains a CCAAT box located 190 nucleotides upstream of the transcription initiation site. Further analysis of 1. 4 kb of the 5' flanking region revealed several potential binding moti fs for transcription factors. This information about the gene structur e may be useful for further studies on the promoter activity.