Sequence organisation and transcriptional regulation of the mouse elastase II and trypsin genes

Elastase II and trypsin mRNAs were cloned in form of their cDNAs from pancreas of strain A/J mice, and their complete nucleotide sequences were determined. The elastase II mRNA is 912 nucleotides long and encodes a protein of 271 amino acids. The cloned trypsin mRNA species is 814 nucleotides long and encodes a protein of 246 amino acids. The elastase II gene, which exists as a single copy in the haploid mouse genome, measures 11.2 kb from cap to poly(A) site and is interrupted by at least seven introns. Between 5 and 10 trypsin genes exist in the mouse genome. Five different trypsin genes, two of which are closely linked in a tail-to-tail manner, were studied in detail. They vary in size between 3.4 and 4.0kb, and all are interrupted by four introns. DNA sequence comparison of the elastase II, trypsin and Amy-2a alpha-amylase genes reveals a conserved 13 nucleotide motif in their 5'-flanking regions. The differential accumulation of the elastase II and trypsin mRNAs in the cytoplasm of the acinar pancreatic cell is regulated predominantly at the transcriptional level.