TERMITOMYCES CLYPEATUS CONTROLS SECRETION OF EXTRACELLULAR AMYLOGLUCOSIDASE BY REGULATING EXOCYTOSIS OF VACUOLAR ENZYME

An extracellular amyloglucosidase (56 kDa) of Termitomyces clypeatus w hich was accumulated intracellularly in absence of Krebs cycle acids i n dextrin medium, remained mostly inside the plasma membrane. The enzy me was localised in mycelial vacuoles as a sucrase-amyloglucosidase ag gregate. The intracellular pool contained both the free sucrase and th e aggregate, while vacuoles contained only aggregate without any free enzyme. The aggregate, partially purified to PAGE homogeneity, contain ed amyloglucosidase and sucrase in the ratio of 1:1. A cellular regula tion, influenced by the presence of Krebs cycle acids, was indicated t o be present at the level of exocytosis of vacuolar enzyme. (C) 1998 P ublished by Elsevier Science B.V. All rights reserved.