Hsf1 activation inhibits rapamycin resistance and TOR signaling in yeast revealed by combined proteomic and genetic analysis

Sricharan Bandhakavi, Hongwei Xie, Brennon O'Callaghan, Hiroshi Sakurai, Do Hyung Kim, Timothy J. Griffin

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

TOR kinases integrate environmental and nutritional signals to regulate cell growth in eukaryotic organisms. Here, we describe results from a study combining quantitative proteomics and comparative expression analysis in the budding yeast, S. cerevisiae, to gain insights into TOR function and regulation. We profiled protein abundance changes under conditions of TOR inhibition by rapamysin treatment and compared this data to existing expression information for corresponding gene products measured under a variety of conditions in yeats. Among proteins showing abundance changes upon rapamycin treatment, almost 90% of them demonstrated homodirectional (i.e., in similar direction) transcriptomic changes under conditions of heat/oxidative stress. Because the known downstream responses regulated by Tor1/2 did not fully explain the extent of overlap between these two conditions, we tested for novel connections between the major regulators of heat/oxidative stress responses and the TOR pathway. Specifically, we hypothesized that activition of regulator(s) of heat/oxidative stress responses phenocopied TOR inhibition and sought to identify these putative TOR inhibitor(s). Among the stress regulators tested, we found that cells (hsf1-R206S, F256S and ssa1-3 ssa2-2) constitutively activated for heat shock transcription factor 1, Hsf1, inhibited rapamycin resistance. Further analysis of the hsf1-R206S, F256S allele revealed that these cells also displayed multiple phenotypes consistent with reduced TOR signaling. Among the multiple Hsf1 tergets elevated in hsf1-R206S, F256S cells, deletion of PIR3 and YRO2 suppressed the TOR-regulated pheriotypes. In contrast to our observation in cells activited for Hsf1, constitutive activition of other regulators of heat/oxidative stress responces, such as Msn2/4 and Hyr1, did not inhibit TOR signaling. Thus, we propose that activated Hsf1 inhibits rapamycin resistance and TOR signaling via elevated expression of specific target genes in S. cerevisiae. Additionally, these results highlight the value of comparative expression analysis between large scale proteomic and transcriptomic datasets to reveal new regulatory connections.

Original languageEnglish (US)
Article numbere1598
JournalPloS one
Volume3
Issue number2
DOIs
StatePublished - Feb 13 2008

Fingerprint

Oxidative stress
Sirolimus
Proteomics
proteomics
Yeast
genetic techniques and protocols
oxidative stress
Yeasts
Chemical activation
yeasts
heat
Oxidative Stress
Heat-Shock Response
transcriptomics
stress response
Genes
TOR Serine-Threonine Kinases
cells
Saccharomyces cerevisiae
Hot Temperature

Cite this

Hsf1 activation inhibits rapamycin resistance and TOR signaling in yeast revealed by combined proteomic and genetic analysis. / Bandhakavi, Sricharan; Xie, Hongwei; O'Callaghan, Brennon; Sakurai, Hiroshi; Kim, Do Hyung; Griffin, Timothy J.

In: PloS one, Vol. 3, No. 2, e1598, 13.02.2008.

Research output: Contribution to journalArticle

@article{5068466311ce455fb2eb8a99f116d09d,
title = "Hsf1 activation inhibits rapamycin resistance and TOR signaling in yeast revealed by combined proteomic and genetic analysis",
abstract = "TOR kinases integrate environmental and nutritional signals to regulate cell growth in eukaryotic organisms. Here, we describe results from a study combining quantitative proteomics and comparative expression analysis in the budding yeast, S. cerevisiae, to gain insights into TOR function and regulation. We profiled protein abundance changes under conditions of TOR inhibition by rapamysin treatment and compared this data to existing expression information for corresponding gene products measured under a variety of conditions in yeats. Among proteins showing abundance changes upon rapamycin treatment, almost 90{\%} of them demonstrated homodirectional (i.e., in similar direction) transcriptomic changes under conditions of heat/oxidative stress. Because the known downstream responses regulated by Tor1/2 did not fully explain the extent of overlap between these two conditions, we tested for novel connections between the major regulators of heat/oxidative stress responses and the TOR pathway. Specifically, we hypothesized that activition of regulator(s) of heat/oxidative stress responses phenocopied TOR inhibition and sought to identify these putative TOR inhibitor(s). Among the stress regulators tested, we found that cells (hsf1-R206S, F256S and ssa1-3 ssa2-2) constitutively activated for heat shock transcription factor 1, Hsf1, inhibited rapamycin resistance. Further analysis of the hsf1-R206S, F256S allele revealed that these cells also displayed multiple phenotypes consistent with reduced TOR signaling. Among the multiple Hsf1 tergets elevated in hsf1-R206S, F256S cells, deletion of PIR3 and YRO2 suppressed the TOR-regulated pheriotypes. In contrast to our observation in cells activited for Hsf1, constitutive activition of other regulators of heat/oxidative stress responces, such as Msn2/4 and Hyr1, did not inhibit TOR signaling. Thus, we propose that activated Hsf1 inhibits rapamycin resistance and TOR signaling via elevated expression of specific target genes in S. cerevisiae. Additionally, these results highlight the value of comparative expression analysis between large scale proteomic and transcriptomic datasets to reveal new regulatory connections.",
author = "Sricharan Bandhakavi and Hongwei Xie and Brennon O'Callaghan and Hiroshi Sakurai and Kim, {Do Hyung} and Griffin, {Timothy J.}",
year = "2008",
month = "2",
day = "13",
doi = "10.1371/journal.pone.0001598",
language = "English (US)",
volume = "3",
journal = "PLoS One",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "2",

}

TY - JOUR

T1 - Hsf1 activation inhibits rapamycin resistance and TOR signaling in yeast revealed by combined proteomic and genetic analysis

AU - Bandhakavi, Sricharan

AU - Xie, Hongwei

AU - O'Callaghan, Brennon

AU - Sakurai, Hiroshi

AU - Kim, Do Hyung

AU - Griffin, Timothy J.

PY - 2008/2/13

Y1 - 2008/2/13

N2 - TOR kinases integrate environmental and nutritional signals to regulate cell growth in eukaryotic organisms. Here, we describe results from a study combining quantitative proteomics and comparative expression analysis in the budding yeast, S. cerevisiae, to gain insights into TOR function and regulation. We profiled protein abundance changes under conditions of TOR inhibition by rapamysin treatment and compared this data to existing expression information for corresponding gene products measured under a variety of conditions in yeats. Among proteins showing abundance changes upon rapamycin treatment, almost 90% of them demonstrated homodirectional (i.e., in similar direction) transcriptomic changes under conditions of heat/oxidative stress. Because the known downstream responses regulated by Tor1/2 did not fully explain the extent of overlap between these two conditions, we tested for novel connections between the major regulators of heat/oxidative stress responses and the TOR pathway. Specifically, we hypothesized that activition of regulator(s) of heat/oxidative stress responses phenocopied TOR inhibition and sought to identify these putative TOR inhibitor(s). Among the stress regulators tested, we found that cells (hsf1-R206S, F256S and ssa1-3 ssa2-2) constitutively activated for heat shock transcription factor 1, Hsf1, inhibited rapamycin resistance. Further analysis of the hsf1-R206S, F256S allele revealed that these cells also displayed multiple phenotypes consistent with reduced TOR signaling. Among the multiple Hsf1 tergets elevated in hsf1-R206S, F256S cells, deletion of PIR3 and YRO2 suppressed the TOR-regulated pheriotypes. In contrast to our observation in cells activited for Hsf1, constitutive activition of other regulators of heat/oxidative stress responces, such as Msn2/4 and Hyr1, did not inhibit TOR signaling. Thus, we propose that activated Hsf1 inhibits rapamycin resistance and TOR signaling via elevated expression of specific target genes in S. cerevisiae. Additionally, these results highlight the value of comparative expression analysis between large scale proteomic and transcriptomic datasets to reveal new regulatory connections.

AB - TOR kinases integrate environmental and nutritional signals to regulate cell growth in eukaryotic organisms. Here, we describe results from a study combining quantitative proteomics and comparative expression analysis in the budding yeast, S. cerevisiae, to gain insights into TOR function and regulation. We profiled protein abundance changes under conditions of TOR inhibition by rapamysin treatment and compared this data to existing expression information for corresponding gene products measured under a variety of conditions in yeats. Among proteins showing abundance changes upon rapamycin treatment, almost 90% of them demonstrated homodirectional (i.e., in similar direction) transcriptomic changes under conditions of heat/oxidative stress. Because the known downstream responses regulated by Tor1/2 did not fully explain the extent of overlap between these two conditions, we tested for novel connections between the major regulators of heat/oxidative stress responses and the TOR pathway. Specifically, we hypothesized that activition of regulator(s) of heat/oxidative stress responses phenocopied TOR inhibition and sought to identify these putative TOR inhibitor(s). Among the stress regulators tested, we found that cells (hsf1-R206S, F256S and ssa1-3 ssa2-2) constitutively activated for heat shock transcription factor 1, Hsf1, inhibited rapamycin resistance. Further analysis of the hsf1-R206S, F256S allele revealed that these cells also displayed multiple phenotypes consistent with reduced TOR signaling. Among the multiple Hsf1 tergets elevated in hsf1-R206S, F256S cells, deletion of PIR3 and YRO2 suppressed the TOR-regulated pheriotypes. In contrast to our observation in cells activited for Hsf1, constitutive activition of other regulators of heat/oxidative stress responces, such as Msn2/4 and Hyr1, did not inhibit TOR signaling. Thus, we propose that activated Hsf1 inhibits rapamycin resistance and TOR signaling via elevated expression of specific target genes in S. cerevisiae. Additionally, these results highlight the value of comparative expression analysis between large scale proteomic and transcriptomic datasets to reveal new regulatory connections.

UR - http://www.scopus.com/inward/record.url?scp=45449086085&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=45449086085&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0001598

DO - 10.1371/journal.pone.0001598

M3 - Article

C2 - 18270585

AN - SCOPUS:45449086085

VL - 3

JO - PLoS One

JF - PLoS One

SN - 1932-6203

IS - 2

M1 - e1598

ER -