Differential fates of invertase mutants in the yeast endoplasmic reticulum.
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.
McCracken
A A
AA
Biology Department, University of Nevada, Reno, NV 89557, USA. mccracke@cmb.unr.edu
Werner
E D
ED
Powell
M J
MJ
Kruse
K B
KB
Brodsky
J L
JL
D000818:Animals; D002645:Chickens; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D006026:Glycoside Hydrolases / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D007136:Immunoglobulins / Q000276:immunology; D009154:Mutation; D043324:beta-Fructofuranosidase
C016512:IgY; D007136:Immunoglobulins; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase