sentence: The prey proteins we used included a negative control ( Alg5p ) , Sec complex subunits ( Sss1p , Sbh1p , Sbh2p , Sec62p , and Sec63p ) , proteins involved in polyubiquitination or ER export of proteins destined for ER-associated degradation ( ERAD ) ( Hrd1p , Der1p , Cue1p , Ubc6p , and Ubc7p ) , and an oligosaccharyltransferase subunit ( Ost1p ) ( Figure 4 ) [ 3 ] .