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Accumulation of exoglucanase activity in yeast secretory mutants blocked at the endoplasmic reticulum level
Author(s) -
Hernández Luis M.,
Olivero Isabel,
Ramírez Manuel,
Larriba Germán
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)80265-4
Subject(s) - endoplasmic reticulum , saccharomyces cerevisiae , mutant , chemistry , yeast , invertase , secretory pathway , secretory protein , biophysics , biochemistry , microbiology and biotechnology , secretion , enzyme , biology , golgi apparatus , gene
Saccharomyces cerevisiae HMSF‐176 (sec 18), a thermosensitive secretory mutant blocked at the endoplasmic reticulum (ER) level, drastically increased its osmotic sensitivity when grown at the restrictive temperature of 37°C in high glucose concentration. This fact led to the erroneous interpretation that glucanases were inactive when localized in the ER. The development of a suitable osmotic stabilizer now indicates that sec 18 accumulates exoglucanase activity. Another ER‐blocked mutant behaved in a similar way. All the accumulated exoglucanase was found in a soluble form. By contrast, a significant portion of the accumulated invertase remained in a membrane‐bound form.