RRC ID 65531
Author Tasnin MN, Takuma T, Sharmin T, Morshed S, Ushimaru T.
Title The vacuole controls nucleolar dynamics and micronucleophagy via the NVJ.
Journal Biochem Biophys Res Commun
Abstract Chromosomes have their own territories and dynamically translocate in response to internal and external cues. However, whether and how territories and the relocation of chromosomes are controlled by other intracellular organelles remains unknown. Upon nutrient starvation and target of rapamycin complex 1 (TORC1) inactivation, micronucleophagy, which preferentially degrades nucleolar proteins, occurs at the nucleus-vacuole junction (NVJ) in budding yeast. Ribosomal DNA (rDNA) is condensed and relocated against the NVJ, whereas nucleolar proteins move towards the NVJ for micronucleophagic degradation, causing dissociation of nucleolar proteins from rDNA. These findings imply that the NVJ is the critical platform in the directional movements of rDNA and nucleolar proteins. Here, we show that cells lacking the NVJ (NVJΔ cells) largely lost rDNA condensation and rDNA-nucleolar protein separation after TORC1 inactivation. The macronucleophagy receptor Atg39, an outer nuclear membrane protein, accumulated at the NVJ and was degraded by micronucleophagy. These suggested that macronucleophagy is also dependent on the presence of the NVJ. However, micronucleophagy, but not macronucleophagy, was abolished in NVJΔ cells. This study clearly demonstrated that vacuoles controls intranuclear events, nucleolar dynamics, from outside of the nucleus via the NVJ under the control of TORC1.
Volume 550
Pages 158-165
Published 2021-4-23
DOI 10.1016/j.bbrc.2021.02.141
PII S0006-291X(21)00368-5
PMID 33706099
MeSH Autophagy-Related Proteins / metabolism Cell Nucleolus / metabolism* Cell Nucleus / genetics Cell Nucleus / metabolism* DNA, Ribosomal / metabolism Mechanistic Target of Rapamycin Complex 1 / antagonists & inhibitors Mechanistic Target of Rapamycin Complex 1 / metabolism Microbial Viability Nuclear Proteins / metabolism Protein Binding Receptors, Cytoplasmic and Nuclear / metabolism Saccharomyces cerevisiae / cytology* Saccharomyces cerevisiae / genetics Saccharomyces cerevisiae / metabolism Saccharomyces cerevisiae Proteins / metabolism Vacuoles / genetics Vacuoles / metabolism*
IF 2.985
DNA material Ifa38-FLAG-GFP11 (RDB16045) Vph1-GFP1-10 (RDB16049)