Cargando…
Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption
Growth resumption from stationary phase in Saccharomyces cerevisiae, is characterized by lipid droplet (LD) consumption and channeling of lipid precursors toward synthesis of membranes. We have previously determined that triacylglycerol lipolysis contributes to a pool of diacylglycerol (DAG) associa...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2020
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7403446/ https://www.ncbi.nlm.nih.gov/pubmed/32850820 http://dx.doi.org/10.3389/fcell.2020.00700 |
_version_ | 1783566944370163712 |
---|---|
author | Ganesan, Suriakarthiga Tavassoli, Marjan Shabits, Brittney N. Zaremberg, Vanina |
author_facet | Ganesan, Suriakarthiga Tavassoli, Marjan Shabits, Brittney N. Zaremberg, Vanina |
author_sort | Ganesan, Suriakarthiga |
collection | PubMed |
description | Growth resumption from stationary phase in Saccharomyces cerevisiae, is characterized by lipid droplet (LD) consumption and channeling of lipid precursors toward synthesis of membranes. We have previously determined that triacylglycerol lipolysis contributes to a pool of diacylglycerol (DAG) associated with the yeast vacuole that is enriched in structures that are in close proximity to LDs. In this study we have monitored these structures using a DAG sensor fused to GFP during isolation of LDs. A unique fraction containing the DAG sensor, with low presence of LDs, was identified. Membranes enriched in the DAG probe were obtained by immunoaffinity purification using a GFP nanobody, and the associated proteome was investigated by mass spectrometry. It was determined this LD-associated fraction was enriched in proteins known to shape the tubular endoplasmic reticulum (ER) like Yop1, Sey1, Rtn1, and Rtn2. Consistently, cells lacking three of these proteins (rtn1Δ rtn2Δ yop1Δ) exhibited delayed LD consumption, larger LDs and abnormal LD distribution. In addition, the triple mutant displayed aberrant localization of the DAG sensor after 5 h of growth resumption from stationary phase. Manipulation of DAG levels by overexpression of the DAG kinase Dgk1, impacted localization of the DAG probe and affected fitness of the triple mutant. Altogether these results link LD consumption to tubular ER expansion as a gateway of lipid precursors that otherwise accumulate in vacuolar associated membranes or other internal compartments. Furthermore, conversion of DAG to phosphatidic acid (PA) in the absence of a functional tubular ER was toxic to cells, suggesting the ratio of PA to DAG is critical to allow growth progression. |
format | Online Article Text |
id | pubmed-7403446 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-74034462020-08-25 Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption Ganesan, Suriakarthiga Tavassoli, Marjan Shabits, Brittney N. Zaremberg, Vanina Front Cell Dev Biol Cell and Developmental Biology Growth resumption from stationary phase in Saccharomyces cerevisiae, is characterized by lipid droplet (LD) consumption and channeling of lipid precursors toward synthesis of membranes. We have previously determined that triacylglycerol lipolysis contributes to a pool of diacylglycerol (DAG) associated with the yeast vacuole that is enriched in structures that are in close proximity to LDs. In this study we have monitored these structures using a DAG sensor fused to GFP during isolation of LDs. A unique fraction containing the DAG sensor, with low presence of LDs, was identified. Membranes enriched in the DAG probe were obtained by immunoaffinity purification using a GFP nanobody, and the associated proteome was investigated by mass spectrometry. It was determined this LD-associated fraction was enriched in proteins known to shape the tubular endoplasmic reticulum (ER) like Yop1, Sey1, Rtn1, and Rtn2. Consistently, cells lacking three of these proteins (rtn1Δ rtn2Δ yop1Δ) exhibited delayed LD consumption, larger LDs and abnormal LD distribution. In addition, the triple mutant displayed aberrant localization of the DAG sensor after 5 h of growth resumption from stationary phase. Manipulation of DAG levels by overexpression of the DAG kinase Dgk1, impacted localization of the DAG probe and affected fitness of the triple mutant. Altogether these results link LD consumption to tubular ER expansion as a gateway of lipid precursors that otherwise accumulate in vacuolar associated membranes or other internal compartments. Furthermore, conversion of DAG to phosphatidic acid (PA) in the absence of a functional tubular ER was toxic to cells, suggesting the ratio of PA to DAG is critical to allow growth progression. Frontiers Media S.A. 2020-07-29 /pmc/articles/PMC7403446/ /pubmed/32850820 http://dx.doi.org/10.3389/fcell.2020.00700 Text en Copyright © 2020 Ganesan, Tavassoli, Shabits and Zaremberg. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Cell and Developmental Biology Ganesan, Suriakarthiga Tavassoli, Marjan Shabits, Brittney N. Zaremberg, Vanina Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption |
title | Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption |
title_full | Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption |
title_fullStr | Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption |
title_full_unstemmed | Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption |
title_short | Tubular ER Associates With Diacylglycerol-Rich Structures During Lipid Droplet Consumption |
title_sort | tubular er associates with diacylglycerol-rich structures during lipid droplet consumption |
topic | Cell and Developmental Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7403446/ https://www.ncbi.nlm.nih.gov/pubmed/32850820 http://dx.doi.org/10.3389/fcell.2020.00700 |
work_keys_str_mv | AT ganesansuriakarthiga tubularerassociateswithdiacylglycerolrichstructuresduringlipiddropletconsumption AT tavassolimarjan tubularerassociateswithdiacylglycerolrichstructuresduringlipiddropletconsumption AT shabitsbrittneyn tubularerassociateswithdiacylglycerolrichstructuresduringlipiddropletconsumption AT zarembergvanina tubularerassociateswithdiacylglycerolrichstructuresduringlipiddropletconsumption |