McCracken A A, Werner E D, Powell M J, Kruse K B, Brodsky J L
Biology Department, University of Nevada, Reno, NV 89557, USA.
Yeast. 2000 Jan 15;16(1):49-55. doi: 10.1002/(SICI)1097-0061(20000115)16:1<49::AID-YEA506>3.0.CO;2-I.
A number of proteins have been identified as substrates for endoplasmic reticulum (ER)-associated protein degradation (ERAD) and we describe here a new model substrate with which to study this process. Two secretion-defective forms of yeast invertase that accumulated in the ER to greatly different levels were examined: Suc2-538p levels were low, while Suc2-533p was present in high amounts. Because Suc2-533p and Suc2-538p mRNA levels were comparable, we examined whether Suc2-538p was targeted for degradation. Both mutant polypeptide levels were unaffected in a yeast strain deficient in vacuolar protease activity and, additionally, we showed that Suc2-538p was stabilized in ERAD-deficient strains, demonstrating that Suc2-538p was a substrate for ERAD.
