FIG. 3.

Addition of a KDEL sequence to MT keeps it localized it in the endoplasmic reticulum and abolishes transformation. (A) The amino acid sequence of the C terminus of MT is shown together with that of three mutants containing either KDEL (MTKDEL), a nonfunctional mutated version of KDEL sequence (MTGGDV), or an MT mutant where the hydrophobic domain has been replaced with the ER-targeting transmembrane sequence from the Sec61β polypeptide (MTSec61β). (B) MTKDEL fails to form foci. Plasmids containing each of the mutants shown in panel A were transfected into Rat2 fibroblasts and assayed for focus formation. The MT mutant used is shown either above or below each panel.