FIG. 7.

Stability-determining amino acids in pathogenic and nonpathogenic G1 tails. (A) Equivalent amounts of the NY-1V and PHV G1 tail mutants indicated were transiently expressed in COS7 cells in the presence (+) or absence (−) of MG132. Protein expression levels were determined by immunoblotting (WB) using anti-GAL4 antibodies. UT, untransfected COS7 lysate. Blots were reprobed for β-actin as an internal loading control. (B) Replacement of residues C1 to C7 and C4 to C7 in the NY-1V G1 tail with PHV residues enhances NY-1V G1 stability. (C) Mutations at residues C1 to C4 alter the stable PHV G1 tail into a proteasomally degraded chimera. Asterisk indicates a nonspecific cellular band.