Figure 1.

Lysine residues and the N terminus are not key ubiquitination sites in the cholesterol-accelerated degradation of SM N100. A, lysine (K) residues were mutated to arginine (R), with the amino acid position numbers of SM N100 indicated in the lysine-less (K-less) construct (left). A bulky mCherry protein was cloned onto the N terminus of SM N100 (right). B and D, CHO-7 cells transiently expressing SM N100 constructs were tested for cholesterol regulation as described under “Experimental procedures” (n = 3–4). C and E, densitometric quantification of the Western blots in B and D. Graphs show mean ± S.E. (n = 3–4), *, p < 0.05, or **, p < 0.01.