Open AccessAsparagine-linked carbohydrate does not determine the cellular location of yeast vacuolar nonspecific alkaline phosphatase
Author(s) -
Delbert Clark,
Jan S. Tkacz,
J. O. Lampen
Publication year - 1982
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.152.2.865-873.1982
Subject(s) - tunicamycin , biochemistry , alkaline phosphatase , biology , vacuole , cytochemistry , asparagine , phosphatase , enzyme , yeast , acid phosphatase , endoplasmic reticulum , unfolded protein response , cytoplasm
The nonspecific alkaline phosphatase of Saccharomyces sp. strain 1710 has been shown by phosphatase cytochemistry to be exclusively located in the vacuole, para-Nitrophenyl phosphate-specific alkaline phosphatase is not detected by this procedure because the activity of this enzyme is sensitive to the fixative agent, glutaraldehyde. To determine whether the oligosaccharide of nonspecific alkaline phosphatase is necessary to transport the enzyme into the vacuole, protoplasts were derepressed in the absence or in the presence of tunicamycin, an antibiotic which interferes with the glycosylation of asparagine residues in proteins. The location of the enzyme in the tunicamycin-treated protoplasts, as determined by electron microscopy and subcellular fractionation, was identical to its location in control protoplasts. In addition, carbohydrate-free alkaline phosphatase was found in vacuoles from tunicamycin-treated protoplasts. Our findings indicate that the asparagine-linked carbohydrate moiety does not determine the cellular location of the enzyme.