Detection of inactive precursors of beta-glucanases in Saccharomyces cerevisiae.
Accumulation and secretion of beta-glucanases have been studied in vivo by using a thermosensitive secretory mutant of Saccharomyces cerevisiae blocked at the endoplasmic reticulum level (sec 18-1). When incubated at the restrictive temperature no accumulation of active glucanases was observed. Following a shift to permissive conditions in the presence of cycloheximide a rise in the internal activity took place. The increase in total glucanase activity was partially due to the activation of an exo-glucanase that hydrolyzes PNPG. It is concluded that glucanases are synthesized in inactive precursor forms and are converted to the active forms in their secretory pathway.
D004721:Endoplasmic Reticulum / Q000201:enzymology; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000302:isolation & purification*; D005959:Glucosidases / Q000302:isolation & purification*; D005960:Glucosides / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D013696:Temperature; D043324:beta-Fructofuranosidase; D001617:beta-Glucosidase / Q000302:isolation & purification*
D004792:Enzyme Precursors; D005960:Glucosides; C018616:2-nitrophenyl-beta-D-glucopyranoside; D005959:Glucosidases; D006026:Glycoside Hydrolases; D001617:beta-Glucosidase; D043324:beta-Fructofuranosidase