The role of the CNOT1 subunit of the CCR4-NOT complex in mRNA deadenylation and cell viability

Kentaro Ito, Akinori Takahashi, Masahiro Morita, Toru Suzuki, Tadashi Yamamoto

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

The human CCR4-NOT deadenylase complex consists of at least nine enzymatic and non-enzymatic subunits. Accumulating evidence suggests that the non-enzymatic subunits are involved in the regulation of mRNA deadenylation, although their precise roles remain to be established. In this study, we addressed the function of the CNOT1 subunit by depleting its expression in HeLa cells. Flow cytometric analysis revealed that the sub G1 fraction was increased in CNOT1-depleted cells. Virtually, the same level of the sub G1 fraction was seen when cells were treated with a mixture of siRNAs targeted against all enzymatic subunits, suggesting that CNOT1 depletion induces apoptosis by destroying the CCR4-NOT-associated deadenylase activity. Further analysis revealed that CNOT1 depletion leads to a reduction in the amount of other CCR4-NOT subunits. Importantly, the specific activity of the CNOT6L immunoprecipitates-associated deadenylase from CNOT1-depleted cells was less than that from control cells. The formation of P-bodies, where mRNA decay is reported to take place, was largely suppressed in CNOT1-depleted cells. Therefore, CNOT1 has an important role in exhibiting enzymatic activity of the CCR4-NOT complex, and thus is critical in control of mRNA deadenylation and mRNA decay. We further showed that CNOT1 depletion enhanced CHOP mRNA levels and activated caspase-4, which is associated with endoplasmic reticulum ER stress-induced apoptosis. Taken together, CNOT1 depletion structurally and functionally deteriorates the CCR4-NOTcomplex and induces stabilization of mRNAs, which results in the increment of translation causing ER stress-mediated apoptosis. We conclude that CNOT1 contributes to cell viability by securing the activity of the CCR4-NOT deadenylase.

Original languageEnglish (US)
Pages (from-to)755-763
Number of pages9
JournalProtein and Cell
Volume2
Issue number9
DOIs
StatePublished - Jan 1 2011
Externally publishedYes

Fingerprint

Cell Survival
Cells
Messenger RNA
RNA Stability
Apoptosis
Endoplasmic Reticulum Stress
Caspases
HeLa Cells
Stabilization

Keywords

  • apoptosis
  • CCR4-NOT
  • deadenylation
  • P-bodies
  • small interfering RNA

ASJC Scopus subject areas

  • Biotechnology
  • Biochemistry
  • Drug Discovery
  • Cell Biology

Cite this

The role of the CNOT1 subunit of the CCR4-NOT complex in mRNA deadenylation and cell viability. / Ito, Kentaro; Takahashi, Akinori; Morita, Masahiro; Suzuki, Toru; Yamamoto, Tadashi.

In: Protein and Cell, Vol. 2, No. 9, 01.01.2011, p. 755-763.

Research output: Contribution to journalArticle

Ito, Kentaro ; Takahashi, Akinori ; Morita, Masahiro ; Suzuki, Toru ; Yamamoto, Tadashi. / The role of the CNOT1 subunit of the CCR4-NOT complex in mRNA deadenylation and cell viability. In: Protein and Cell. 2011 ; Vol. 2, No. 9. pp. 755-763.
@article{c35a8c16012349309947f0b225fcb2db,
title = "The role of the CNOT1 subunit of the CCR4-NOT complex in mRNA deadenylation and cell viability",
abstract = "The human CCR4-NOT deadenylase complex consists of at least nine enzymatic and non-enzymatic subunits. Accumulating evidence suggests that the non-enzymatic subunits are involved in the regulation of mRNA deadenylation, although their precise roles remain to be established. In this study, we addressed the function of the CNOT1 subunit by depleting its expression in HeLa cells. Flow cytometric analysis revealed that the sub G1 fraction was increased in CNOT1-depleted cells. Virtually, the same level of the sub G1 fraction was seen when cells were treated with a mixture of siRNAs targeted against all enzymatic subunits, suggesting that CNOT1 depletion induces apoptosis by destroying the CCR4-NOT-associated deadenylase activity. Further analysis revealed that CNOT1 depletion leads to a reduction in the amount of other CCR4-NOT subunits. Importantly, the specific activity of the CNOT6L immunoprecipitates-associated deadenylase from CNOT1-depleted cells was less than that from control cells. The formation of P-bodies, where mRNA decay is reported to take place, was largely suppressed in CNOT1-depleted cells. Therefore, CNOT1 has an important role in exhibiting enzymatic activity of the CCR4-NOT complex, and thus is critical in control of mRNA deadenylation and mRNA decay. We further showed that CNOT1 depletion enhanced CHOP mRNA levels and activated caspase-4, which is associated with endoplasmic reticulum ER stress-induced apoptosis. Taken together, CNOT1 depletion structurally and functionally deteriorates the CCR4-NOTcomplex and induces stabilization of mRNAs, which results in the increment of translation causing ER stress-mediated apoptosis. We conclude that CNOT1 contributes to cell viability by securing the activity of the CCR4-NOT deadenylase.",
keywords = "apoptosis, CCR4-NOT, deadenylation, P-bodies, small interfering RNA",
author = "Kentaro Ito and Akinori Takahashi and Masahiro Morita and Toru Suzuki and Tadashi Yamamoto",
year = "2011",
month = "1",
day = "1",
doi = "10.1007/s13238-011-1092-4",
language = "English (US)",
volume = "2",
pages = "755--763",
journal = "Protein and Cell",
issn = "1674-800X",
publisher = "Springer-Verlag GmbH and Co. KG",
number = "9",

}

TY - JOUR

T1 - The role of the CNOT1 subunit of the CCR4-NOT complex in mRNA deadenylation and cell viability

AU - Ito, Kentaro

AU - Takahashi, Akinori

AU - Morita, Masahiro

AU - Suzuki, Toru

AU - Yamamoto, Tadashi

PY - 2011/1/1

Y1 - 2011/1/1

N2 - The human CCR4-NOT deadenylase complex consists of at least nine enzymatic and non-enzymatic subunits. Accumulating evidence suggests that the non-enzymatic subunits are involved in the regulation of mRNA deadenylation, although their precise roles remain to be established. In this study, we addressed the function of the CNOT1 subunit by depleting its expression in HeLa cells. Flow cytometric analysis revealed that the sub G1 fraction was increased in CNOT1-depleted cells. Virtually, the same level of the sub G1 fraction was seen when cells were treated with a mixture of siRNAs targeted against all enzymatic subunits, suggesting that CNOT1 depletion induces apoptosis by destroying the CCR4-NOT-associated deadenylase activity. Further analysis revealed that CNOT1 depletion leads to a reduction in the amount of other CCR4-NOT subunits. Importantly, the specific activity of the CNOT6L immunoprecipitates-associated deadenylase from CNOT1-depleted cells was less than that from control cells. The formation of P-bodies, where mRNA decay is reported to take place, was largely suppressed in CNOT1-depleted cells. Therefore, CNOT1 has an important role in exhibiting enzymatic activity of the CCR4-NOT complex, and thus is critical in control of mRNA deadenylation and mRNA decay. We further showed that CNOT1 depletion enhanced CHOP mRNA levels and activated caspase-4, which is associated with endoplasmic reticulum ER stress-induced apoptosis. Taken together, CNOT1 depletion structurally and functionally deteriorates the CCR4-NOTcomplex and induces stabilization of mRNAs, which results in the increment of translation causing ER stress-mediated apoptosis. We conclude that CNOT1 contributes to cell viability by securing the activity of the CCR4-NOT deadenylase.

AB - The human CCR4-NOT deadenylase complex consists of at least nine enzymatic and non-enzymatic subunits. Accumulating evidence suggests that the non-enzymatic subunits are involved in the regulation of mRNA deadenylation, although their precise roles remain to be established. In this study, we addressed the function of the CNOT1 subunit by depleting its expression in HeLa cells. Flow cytometric analysis revealed that the sub G1 fraction was increased in CNOT1-depleted cells. Virtually, the same level of the sub G1 fraction was seen when cells were treated with a mixture of siRNAs targeted against all enzymatic subunits, suggesting that CNOT1 depletion induces apoptosis by destroying the CCR4-NOT-associated deadenylase activity. Further analysis revealed that CNOT1 depletion leads to a reduction in the amount of other CCR4-NOT subunits. Importantly, the specific activity of the CNOT6L immunoprecipitates-associated deadenylase from CNOT1-depleted cells was less than that from control cells. The formation of P-bodies, where mRNA decay is reported to take place, was largely suppressed in CNOT1-depleted cells. Therefore, CNOT1 has an important role in exhibiting enzymatic activity of the CCR4-NOT complex, and thus is critical in control of mRNA deadenylation and mRNA decay. We further showed that CNOT1 depletion enhanced CHOP mRNA levels and activated caspase-4, which is associated with endoplasmic reticulum ER stress-induced apoptosis. Taken together, CNOT1 depletion structurally and functionally deteriorates the CCR4-NOTcomplex and induces stabilization of mRNAs, which results in the increment of translation causing ER stress-mediated apoptosis. We conclude that CNOT1 contributes to cell viability by securing the activity of the CCR4-NOT deadenylase.

KW - apoptosis

KW - CCR4-NOT

KW - deadenylation

KW - P-bodies

KW - small interfering RNA

UR - http://www.scopus.com/inward/record.url?scp=80955125826&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80955125826&partnerID=8YFLogxK

U2 - 10.1007/s13238-011-1092-4

DO - 10.1007/s13238-011-1092-4

M3 - Article

VL - 2

SP - 755

EP - 763

JO - Protein and Cell

JF - Protein and Cell

SN - 1674-800X

IS - 9

ER -