MED14 tethers mediator to the N-terminal domain of peroxisome proliferator-activated receptor gamma and is required for full transcriptional activity and adipogenesis

Lars Grøntved, Maria S Madsen, Michael Boergesen, Robert G Roeder, Susanne Mandrup

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

The Mediator subunit MED1/TRAP220/DRIP205/PBP interacts directly with many nuclear receptors and was long thought to be responsible for tethering Mediator to peroxisome proliferator-activated receptor (PPAR)-responsive promoters. However, it was demonstrated recently that PPARgamma can recruit Mediator by MED1-independent mechanisms. Here, we show that target gene activation by ectopically expressed PPARgamma and PPARalpha is independent of MED1. Consistent with this finding, recruitment of PPARgamma, MED6, MED8, TATA box-binding protein (TBP), and RNA polymerase II (RNAPII) to the enhancer and proximal promoter of the PPARgamma target gene Fabp4 is also independent of MED1. Using a small interfering RNA (siRNA)-based approach, we identify MED14 as a novel critical Mediator component for PPARgamma-dependent transactivation, and we demonstrate that MED14 interacts directly with the N terminus of PPARgamma in a ligand-independent manner. Interestingly, MED14 knockdown does not affect the recruitment of PPARgamma, MED6, and MED8 to the Fabp4 enhancer but does reduce their occupancy of the Fabp4 proximal promoter. In agreement with the necessity of MED14 for PPARgamma transcriptional activity, we show that knockdown of MED14 impairs adipogenesis of 3T3-L1 cells. Thus, MED14 constitutes a novel anchoring point between Mediator and the N-terminal domain of PPARgamma that is necessary for functional PPARgamma-mediated recruitment of Mediator and transactivation of PPARgamma subtype-specific target genes.
OriginalsprogEngelsk
TidsskriftMolecular and Cellular Biology
Vol/bind30
Udgave nummer9
Sider (fra-til)2155-69
Antal sider15
ISSN0270-7306
DOI
StatusUdgivet - 1. maj 2010

Fingeraftryk

Adipogenesis
PPAR gamma
Transcriptional Activation
TATA-Box Binding Protein
3T3-L1 Cells
PPAR alpha
RNA Polymerase II
Cytoplasmic and Nuclear Receptors
Small Interfering RNA

Citer dette

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title = "MED14 tethers mediator to the N-terminal domain of peroxisome proliferator-activated receptor gamma and is required for full transcriptional activity and adipogenesis",
abstract = "The Mediator subunit MED1/TRAP220/DRIP205/PBP interacts directly with many nuclear receptors and was long thought to be responsible for tethering Mediator to peroxisome proliferator-activated receptor (PPAR)-responsive promoters. However, it was demonstrated recently that PPARgamma can recruit Mediator by MED1-independent mechanisms. Here, we show that target gene activation by ectopically expressed PPARgamma and PPARalpha is independent of MED1. Consistent with this finding, recruitment of PPARgamma, MED6, MED8, TATA box-binding protein (TBP), and RNA polymerase II (RNAPII) to the enhancer and proximal promoter of the PPARgamma target gene Fabp4 is also independent of MED1. Using a small interfering RNA (siRNA)-based approach, we identify MED14 as a novel critical Mediator component for PPARgamma-dependent transactivation, and we demonstrate that MED14 interacts directly with the N terminus of PPARgamma in a ligand-independent manner. Interestingly, MED14 knockdown does not affect the recruitment of PPARgamma, MED6, and MED8 to the Fabp4 enhancer but does reduce their occupancy of the Fabp4 proximal promoter. In agreement with the necessity of MED14 for PPARgamma transcriptional activity, we show that knockdown of MED14 impairs adipogenesis of 3T3-L1 cells. Thus, MED14 constitutes a novel anchoring point between Mediator and the N-terminal domain of PPARgamma that is necessary for functional PPARgamma-mediated recruitment of Mediator and transactivation of PPARgamma subtype-specific target genes.",
keywords = "3T3-L1 Cells, Adipogenesis, Animals, Enhancer Elements, Genetic, Fatty Acid-Binding Proteins, Gene Knockdown Techniques, Humans, Luciferases, Mediator Complex Subunit 1, Mice, PPAR gamma, Promoter Regions, Genetic, Protein Binding, Protein Structure, Tertiary, Protein Subunits, RNA, Small Interfering, Transcription Factors, Transcription, Genetic, Transcriptional Activation, Transfection",
author = "Lars Gr{\o}ntved and Madsen, {Maria S} and Michael Boergesen and Roeder, {Robert G} and Susanne Mandrup",
year = "2010",
month = "5",
day = "1",
doi = "10.1128/MCB.01238-09",
language = "English",
volume = "30",
pages = "2155--69",
journal = "Molecular and Cellular Biology",
issn = "0270-7306",
publisher = "American Society for Microbiology",
number = "9",

}

MED14 tethers mediator to the N-terminal domain of peroxisome proliferator-activated receptor gamma and is required for full transcriptional activity and adipogenesis. / Grøntved, Lars; Madsen, Maria S; Boergesen, Michael; Roeder, Robert G; Mandrup, Susanne.

I: Molecular and Cellular Biology, Bind 30, Nr. 9, 01.05.2010, s. 2155-69.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - MED14 tethers mediator to the N-terminal domain of peroxisome proliferator-activated receptor gamma and is required for full transcriptional activity and adipogenesis

AU - Grøntved, Lars

AU - Madsen, Maria S

AU - Boergesen, Michael

AU - Roeder, Robert G

AU - Mandrup, Susanne

PY - 2010/5/1

Y1 - 2010/5/1

N2 - The Mediator subunit MED1/TRAP220/DRIP205/PBP interacts directly with many nuclear receptors and was long thought to be responsible for tethering Mediator to peroxisome proliferator-activated receptor (PPAR)-responsive promoters. However, it was demonstrated recently that PPARgamma can recruit Mediator by MED1-independent mechanisms. Here, we show that target gene activation by ectopically expressed PPARgamma and PPARalpha is independent of MED1. Consistent with this finding, recruitment of PPARgamma, MED6, MED8, TATA box-binding protein (TBP), and RNA polymerase II (RNAPII) to the enhancer and proximal promoter of the PPARgamma target gene Fabp4 is also independent of MED1. Using a small interfering RNA (siRNA)-based approach, we identify MED14 as a novel critical Mediator component for PPARgamma-dependent transactivation, and we demonstrate that MED14 interacts directly with the N terminus of PPARgamma in a ligand-independent manner. Interestingly, MED14 knockdown does not affect the recruitment of PPARgamma, MED6, and MED8 to the Fabp4 enhancer but does reduce their occupancy of the Fabp4 proximal promoter. In agreement with the necessity of MED14 for PPARgamma transcriptional activity, we show that knockdown of MED14 impairs adipogenesis of 3T3-L1 cells. Thus, MED14 constitutes a novel anchoring point between Mediator and the N-terminal domain of PPARgamma that is necessary for functional PPARgamma-mediated recruitment of Mediator and transactivation of PPARgamma subtype-specific target genes.

AB - The Mediator subunit MED1/TRAP220/DRIP205/PBP interacts directly with many nuclear receptors and was long thought to be responsible for tethering Mediator to peroxisome proliferator-activated receptor (PPAR)-responsive promoters. However, it was demonstrated recently that PPARgamma can recruit Mediator by MED1-independent mechanisms. Here, we show that target gene activation by ectopically expressed PPARgamma and PPARalpha is independent of MED1. Consistent with this finding, recruitment of PPARgamma, MED6, MED8, TATA box-binding protein (TBP), and RNA polymerase II (RNAPII) to the enhancer and proximal promoter of the PPARgamma target gene Fabp4 is also independent of MED1. Using a small interfering RNA (siRNA)-based approach, we identify MED14 as a novel critical Mediator component for PPARgamma-dependent transactivation, and we demonstrate that MED14 interacts directly with the N terminus of PPARgamma in a ligand-independent manner. Interestingly, MED14 knockdown does not affect the recruitment of PPARgamma, MED6, and MED8 to the Fabp4 enhancer but does reduce their occupancy of the Fabp4 proximal promoter. In agreement with the necessity of MED14 for PPARgamma transcriptional activity, we show that knockdown of MED14 impairs adipogenesis of 3T3-L1 cells. Thus, MED14 constitutes a novel anchoring point between Mediator and the N-terminal domain of PPARgamma that is necessary for functional PPARgamma-mediated recruitment of Mediator and transactivation of PPARgamma subtype-specific target genes.

KW - 3T3-L1 Cells

KW - Adipogenesis

KW - Animals

KW - Enhancer Elements, Genetic

KW - Fatty Acid-Binding Proteins

KW - Gene Knockdown Techniques

KW - Humans

KW - Luciferases

KW - Mediator Complex Subunit 1

KW - Mice

KW - PPAR gamma

KW - Promoter Regions, Genetic

KW - Protein Binding

KW - Protein Structure, Tertiary

KW - Protein Subunits

KW - RNA, Small Interfering

KW - Transcription Factors

KW - Transcription, Genetic

KW - Transcriptional Activation

KW - Transfection

U2 - 10.1128/MCB.01238-09

DO - 10.1128/MCB.01238-09

M3 - Journal article

VL - 30

SP - 2155

EP - 2169

JO - Molecular and Cellular Biology

JF - Molecular and Cellular Biology

SN - 0270-7306

IS - 9

ER -