UASt sequences regulate expression of a coding sequence that is comprised of a Tag:SS(nec) secretion signal peptide, the mature Hsap\PRNP peptide (amino acid residues 23-230 of GB:AF076976) carrying the V129 polymorphism, and the Hsap\PRNP glycosylphosphatidylinositol anchor signal sequence (amino acid residues 231-253).