Roles of vacuolar proteases in the autophagic degradation of nuclei and other substrates in Aspergillus oryzae.

Authors

Hiroto Yamaguchi, Junka Fujita, Manabu Arioka

Published in

Molecular biology reports. Volume 53. Issue 1. Oct 25, 2026. Epub Oct 25, 2026.

Abstract

We previously reported that in the filamentous fungus Aspergillus oryzae entire nuclei were degraded by autophagy when cells are exposed to nutrient starvation. In this study we investigated the role of vacuolar proteases in autophagic degradation of nuclei (nucleophagy) and bulk autophagy in A. oryzae.
We constructed A. oryzae mutants disrupted for pepE and Aoprb1 encoding the orthologs of major vacuolar proteases Pep4 and Prb1, respectively, in Saccharomyces cerevisiae. Surprisingly, disruption of pepE did not result in any autophagy-related phenotypic alterations such as reduced conidiation and decrease in starvation-induced substrate degradation. In contrast, Aoprb1 disruptant exhibited apparently contradictory phenotypes: while conidiation was severely impaired and accumulation of autophagic bodies in the vacuoles was observed, degradation of AoAtg8 and histone H2B, markers for autophagic flux and nucleophagy, respectively, only slightly or not significantly reduced. Double disruption of pepE and Aoprb1 markedly impaired AoAtg8 degradation, whereas nucleophagy was only partially reduced.
These results suggest that in A. oryzae PepE does not play a major role in the autophagic processes, and that nuclear degradation requires additional protease(s) besides PepE and AoPrb1.

PMID:
42927585
Bibliographic data and abstract were imported from PubMed on 26 Oct 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.