Supplementary Table 1 Characterisation of Der1 mutants generated by site-directed mutagenesis.

The indicated amino acids in Der1 were changed to alanine (A), leucine (L) or tryptophan (W) and analysed for their stability and their ability to promote CPY^* degradation by cycloheximide decay assay. The interaction to Usa1 and the ability to form oligomers were determined by immunoprecipitation. Der1 transmembrane mutants deficient for CPY^* degradation and used for following experiments are highlighted in red.