MOLECULAR-CLONING AND EXPRESSION OF RAT KALLISTATIN GENE

We have previously purified and cloned human kallistatin and rat kalli krein-binding protein (RKBP), which are tissue kallikrein inhibitors b elonging to the serine proteinase inhibitor superfamily. In this study , we have cloned and sequenced the gene encoding rat kallistatin with Phe-Phe-Ser-Ala-Gln at positions P2-P3', which is identical to the rea ctive center of human kallistatin. Rat kallistatin is highly similar t o human kallistatin, sharing 68% and 57% sequence identity at the cDNA and the amino acid levels. The rat kallistatin gene exists in a singl e copy and is located on chromosome 6. An SphI RFLP is found between S HR and WKY rats at or near the rat kallistatin gene locus. Two amino a cid polymorphisms of the rat kallistatin gene between these two strain s were found by sequence analysis. A candidate promoter in the 5'-flan king region (109 bp) of the rat kallistatin gene has been identified b y reporter assays. The expression of rat kallistatin in the liver is g rowth-dependent and down-regulated during acute phase inflammation. Re combinant rat kallistatin produced in E. coli is able to bind to tissu e kallikrein, and the interaction is inhibited by heparin. These chara cteristics define rat kallistatin as the counterpart of human kallista tin. (C) 1997 Elsevier Science B.V.