Figure 7.

A1PiZ resides only in membrane protected fractions. Cytosol (Cyt) and microsome fractions (membrane) were prepared from BY4742 (WT) and atg14Δ strains expressing A1PiZ from the pYESA1PiZ high level expression vector, as described in Materials and Methods. The microsome fractions were left untreated (–) or were treated with trypsin (+) or with trypsin and Triton X-100 (+). Fractions were examined by immunoblot analysis using antisera to either the cytosolic marker protein PGK (a), A1Pi (b), or the ER luminal chaperone, BiP (c).