LOCALIZATION OF A PROTEIN A-TAGGED KEX2 PROTEIN TO THE VACUOLE OF SACCHAROMYCES-CEREVISIAE ALLOWS RAPID PURIFICATION OF VACUOLAR MEMBRANES

We have previously reported an immunoisolation procedure which allows purification of Kex2p-containing Golgi membranes from lysed yeast cell s. In order to evaluate the use of tagging procedures in organelle iso lation we set out to isolate the same Golgi membrane fraction using a version of the Kex2 protease that had been affinity-tagged at its C-te rminus. This protein is found to be localized in the vacuole, providin g the basis of a method for the affinity-purification of vacuolar memb ranes.