Retention of p63 in an ER-Golgi intermediate compartment depends on the presence of all three of its domains and on its ability to form oligomers

An additional construct was created that has the same mutation as MP1 except for amino acid position 5 where the original lysine was retained (A94-101, RTG-SKt0GttK2tC_F'-A [MP4]; Fig. 7 ). Following transient transfection and immunofluorescence microscopy, this mutant showed two different localizations. Some of the chimeric protein was consistenfly detected on the cell surface (Fig. 8 h) while the rernaining protein was predominantly found in the ER (Fig. 8 g) . The latter finding suggested that the introduced changes might partly impair proper folding of the mutant protein which may prevent its exit from the ER. The presence of MP4 at the cell surface shows that K 5 cannot restore correct localization of p63 in the absence of the three positively charged amino acid-glycine combinations.