In CHO 7 cells not expressing hamster __NODE__ protein and overproducing __SP__ __NODE__ protein , a protein chimera composed of mutant hamster __NODE__ protein ( C terminal truncation 998 End with its transmembrane domain deleted ) and of a protein fragment ( aa sequence KDEL ) in CHO 7 cells not expressing hamster __NODE__ protein and overproducing __SP__ __NODE__ protein causes little or no change in cleavage of mutant __SP__ __NODE__ protein ( R519A with its Site 1 __NODE__ recognition sequence mutated ) .