Skip to main content
. 2012 Jul 9;3(10):767–781. doi: 10.1021/cn3000718

Figure 2.

Figure 2

Characterization of the CHT endocytosis motif by alanine-scanning mutagenesis. (A) The 1° endocytic sequence motif of CHT identified in Figure 1 is conserved across multiple species. (B) Analysis of choline transport in transiently transfected COS-7 cells reveals that alanine substitution of specific CHT residues within this interval results in a significant increase in CHT-mediated choline transport (*p < 0.05 by ANOVA followed by Bonferroni’s post-test; n = 4–7 for each mutant). The L531A mutation gave the greatest single residue mutation uptake increase. The combined L531A and V532A combination gave the greatest uptake increase. This mutant was chosen for further characterization, referred to as CHT LV-AA in text. (C) The cotransfection of a dominant negative mutant of dynamin (K44A) does not contribute to additional increases in the activity of CHT mutants within the basal endocytic motif. (D) The sequence of 522–532 in CHT has elements in common with the characterized targeting sequence of other synaptic vesicle proteins, specifically the dileucine-type motif identified as the most active CHT mutation.46,69.