The Journal of General and Applied Microbiology
Online ISSN : 1349-8037
Print ISSN : 0022-1260
Full Papers
Carbon and nitrogen depletion-induced nucleophagy and selective autophagic sequestration of a whole nucleus in multinucleate cells of the filamentous fungus Aspergillus oryzae
Takashi KikumaTakahiro MitaniTakahiro KoharaJun-ichi MaruyamaKatsuhiko Kitamoto
Author information

Volume 63 (2017) Issue 2 Pages 139-146

Download PDF (3792K) Contact us

Autophagy is a conserved cellular degradation process in eukaryotes, in which cytoplasmic components and organelles are digested in vacuoles/lysosomes. Recently, autophagic degradation of nuclear materials, termed “nucleophagy”, has been reported. In the multinucleate filamentous fungus Aspergillus oryzae, a whole nucleus is degraded by nucleophagy after prolonged culture. While developing an H2B-EGFP processing assay for the evaluation of nucleophagy in A. oryzae, we found that nucleophagy is efficiently induced by carbon or nitrogen depletion. Microscopic observations in a carbon depletion condition clearly demonstrated that autophagosomes selectively sequester a particular nucleus, despite the presence of multiple nuclei in the same cell. Furthermore, AoNsp1, the A. oryzae homolog of the yeast nucleoporin Nsp1p, mainly localized at the nuclear periphery, but its localization was restricted to the opposite side of the autophagosome being formed around a nucleus. In contrast, the perinuclear ER visualized with the calnexin AoClxA was not morphologically affected by nucleophagy. The findings of nucleophagy-inducing conditions enabled us to characterize the morphological process of autophagic degradation of a whole nucleus in multinucleate cells.

Information related to the author
© 2017, Applied Microbiology, Molecular and Cellular Biosciences Research Foundation
Previous article Next article

Recently visited articles