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Dual functions of TAF7L in adipocyte differentiation.

Zhou H, Kaplan T, Li Y, Grubisic I, Zhang Z, Wang PJ, Eisen MB, Tjian R - Elife (2013)

Bottom Line: Depletion of TAF7L reduced adipocyte-specific gene expression, compromised adipocyte differentiation, and WAT development as well.Genome-wide mRNA-seq expression profiling and ChIP-seq binding studies confirmed that TAF7L is required for activating adipocyte-specific genes via a dual mechanism wherein it interacts with PPARγ at enhancers and TBP/Pol II at core promoters.In vitro binding studies confirmed that TAF7L forms complexes with both TBP and PPARγ.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cell Biology , Howard Hughes Medical Institute, University of California, Berkeley , Berkeley , United States ; Li Ka Shing Center For Biomedical and Health Sciences, CIRM Center of Excellence, University of California, Berkeley , Berkeley , United States.

ABSTRACT
The diverse transcriptional mechanisms governing cellular differentiation and development of mammalian tissue remains poorly understood. Here we report that TAF7L, a paralogue of TFIID subunit TAF7, is enriched in adipocytes and white fat tissue (WAT) in mouse. Depletion of TAF7L reduced adipocyte-specific gene expression, compromised adipocyte differentiation, and WAT development as well. Ectopic expression of TAF7L in myoblasts reprograms these muscle precursors into adipocytes upon induction. Genome-wide mRNA-seq expression profiling and ChIP-seq binding studies confirmed that TAF7L is required for activating adipocyte-specific genes via a dual mechanism wherein it interacts with PPARγ at enhancers and TBP/Pol II at core promoters. In vitro binding studies confirmed that TAF7L forms complexes with both TBP and PPARγ. These findings suggest that TAF7L plays an integral role in adipocyte gene expression by targeting enhancers as a cofactor for PPARγ and promoters as a component of the core transcriptional machinery.DOI:http://dx.doi.org/10.7554/eLife.00170.001.

No MeSH data available.


Related in: MedlinePlus

Taf7l is required for WAT development in vivo.(A) Oil red O staining to detect mature adipocytes from 5 day differentiated primary fibroblasts derived from adipose tissue of wild-type (WT) and Taf7l-deficient mice (KO). (B) mRNA levels of adipocyte-specific genes by RT-qPCR on WT and Taf7l KO primary fibroblasts post differentiation from (A), mRNA levels in WT cells were assigned to 1, mRNA levels of each gene in Taf7l KO cells were compared to WT cells, *p<0.05, data is mean and s.e.m is from triplicates. RT-qPCR was normalized to the amount of total mRNA. (C) Average food intake of WT and KO mice from week 4 to week 9 after birth. n = 9. (D) Average body weights of WT and KO littermates from week 4 to week 9 after birth, n = 9. (E) H&E and FABP4 antibody stain subcutaneous fat cells in E18.5 WT and Taf7l KO embryos, left panel magnification, ×5; right panel magnification, ×20; red arrows indicate fat cells stained by FABP4. (F) Taf7l KO mice exhibits less fat tissue than WT littermate. Shown are representative photographs of 1-month-old mice with skin removed from both front and back views. (G) Taf7l KO mouse exhibits less fat formation than WT littermate. Shown is a representative photograph of 4-month-old mouse with skin removal.DOI:http://dx.doi.org/10.7554/eLife.00170.009
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fig4: Taf7l is required for WAT development in vivo.(A) Oil red O staining to detect mature adipocytes from 5 day differentiated primary fibroblasts derived from adipose tissue of wild-type (WT) and Taf7l-deficient mice (KO). (B) mRNA levels of adipocyte-specific genes by RT-qPCR on WT and Taf7l KO primary fibroblasts post differentiation from (A), mRNA levels in WT cells were assigned to 1, mRNA levels of each gene in Taf7l KO cells were compared to WT cells, *p<0.05, data is mean and s.e.m is from triplicates. RT-qPCR was normalized to the amount of total mRNA. (C) Average food intake of WT and KO mice from week 4 to week 9 after birth. n = 9. (D) Average body weights of WT and KO littermates from week 4 to week 9 after birth, n = 9. (E) H&E and FABP4 antibody stain subcutaneous fat cells in E18.5 WT and Taf7l KO embryos, left panel magnification, ×5; right panel magnification, ×20; red arrows indicate fat cells stained by FABP4. (F) Taf7l KO mice exhibits less fat tissue than WT littermate. Shown are representative photographs of 1-month-old mice with skin removed from both front and back views. (G) Taf7l KO mouse exhibits less fat formation than WT littermate. Shown is a representative photograph of 4-month-old mouse with skin removal.DOI:http://dx.doi.org/10.7554/eLife.00170.009

Mentions: To assess Taf7l function in adipogenesis in vivo, we first isolated primary adipocyte fibroblasts from WAT of Taf7l knockout (KO) mice and littermate controls (WT) and tested their ability to undergo adipogenesis. As revealed by Oil red O staining, Taf7l KO fibroblasts produced very few, if any, lipid-filled adipocytes compared to WT cells in response to adipogenic induction (Figure 4A). RT-qPCR analysis confirmed that ablation of Taf7l also suppresses the upregulation of adipocyte-specific genes during differentiation (Figure 4B). These results indicate a requirement for Taf7l in adipocyte differentiation of primary adipocyte fibroblasts, consistent with our results from C3H10T1/2 cells. As expected, loss of Taf7l caused no obvious change in mRNA or protein levels of other TFIID subunits (data not shown), suggesting that deletion of Taf7l is unlikely to affect TFIID integrity or function in vivo, in agreement with previous observations that Taf7l-deficient mice appear normal except for germ cell developmental defects (Cheng et al., 2007).10.7554/eLife.00170.009Figure 4.Taf7l is required for WAT development in vivo.


Dual functions of TAF7L in adipocyte differentiation.

Zhou H, Kaplan T, Li Y, Grubisic I, Zhang Z, Wang PJ, Eisen MB, Tjian R - Elife (2013)

Taf7l is required for WAT development in vivo.(A) Oil red O staining to detect mature adipocytes from 5 day differentiated primary fibroblasts derived from adipose tissue of wild-type (WT) and Taf7l-deficient mice (KO). (B) mRNA levels of adipocyte-specific genes by RT-qPCR on WT and Taf7l KO primary fibroblasts post differentiation from (A), mRNA levels in WT cells were assigned to 1, mRNA levels of each gene in Taf7l KO cells were compared to WT cells, *p<0.05, data is mean and s.e.m is from triplicates. RT-qPCR was normalized to the amount of total mRNA. (C) Average food intake of WT and KO mice from week 4 to week 9 after birth. n = 9. (D) Average body weights of WT and KO littermates from week 4 to week 9 after birth, n = 9. (E) H&E and FABP4 antibody stain subcutaneous fat cells in E18.5 WT and Taf7l KO embryos, left panel magnification, ×5; right panel magnification, ×20; red arrows indicate fat cells stained by FABP4. (F) Taf7l KO mice exhibits less fat tissue than WT littermate. Shown are representative photographs of 1-month-old mice with skin removed from both front and back views. (G) Taf7l KO mouse exhibits less fat formation than WT littermate. Shown is a representative photograph of 4-month-old mouse with skin removal.DOI:http://dx.doi.org/10.7554/eLife.00170.009
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fig4: Taf7l is required for WAT development in vivo.(A) Oil red O staining to detect mature adipocytes from 5 day differentiated primary fibroblasts derived from adipose tissue of wild-type (WT) and Taf7l-deficient mice (KO). (B) mRNA levels of adipocyte-specific genes by RT-qPCR on WT and Taf7l KO primary fibroblasts post differentiation from (A), mRNA levels in WT cells were assigned to 1, mRNA levels of each gene in Taf7l KO cells were compared to WT cells, *p<0.05, data is mean and s.e.m is from triplicates. RT-qPCR was normalized to the amount of total mRNA. (C) Average food intake of WT and KO mice from week 4 to week 9 after birth. n = 9. (D) Average body weights of WT and KO littermates from week 4 to week 9 after birth, n = 9. (E) H&E and FABP4 antibody stain subcutaneous fat cells in E18.5 WT and Taf7l KO embryos, left panel magnification, ×5; right panel magnification, ×20; red arrows indicate fat cells stained by FABP4. (F) Taf7l KO mice exhibits less fat tissue than WT littermate. Shown are representative photographs of 1-month-old mice with skin removed from both front and back views. (G) Taf7l KO mouse exhibits less fat formation than WT littermate. Shown is a representative photograph of 4-month-old mouse with skin removal.DOI:http://dx.doi.org/10.7554/eLife.00170.009
Mentions: To assess Taf7l function in adipogenesis in vivo, we first isolated primary adipocyte fibroblasts from WAT of Taf7l knockout (KO) mice and littermate controls (WT) and tested their ability to undergo adipogenesis. As revealed by Oil red O staining, Taf7l KO fibroblasts produced very few, if any, lipid-filled adipocytes compared to WT cells in response to adipogenic induction (Figure 4A). RT-qPCR analysis confirmed that ablation of Taf7l also suppresses the upregulation of adipocyte-specific genes during differentiation (Figure 4B). These results indicate a requirement for Taf7l in adipocyte differentiation of primary adipocyte fibroblasts, consistent with our results from C3H10T1/2 cells. As expected, loss of Taf7l caused no obvious change in mRNA or protein levels of other TFIID subunits (data not shown), suggesting that deletion of Taf7l is unlikely to affect TFIID integrity or function in vivo, in agreement with previous observations that Taf7l-deficient mice appear normal except for germ cell developmental defects (Cheng et al., 2007).10.7554/eLife.00170.009Figure 4.Taf7l is required for WAT development in vivo.

Bottom Line: Depletion of TAF7L reduced adipocyte-specific gene expression, compromised adipocyte differentiation, and WAT development as well.Genome-wide mRNA-seq expression profiling and ChIP-seq binding studies confirmed that TAF7L is required for activating adipocyte-specific genes via a dual mechanism wherein it interacts with PPARγ at enhancers and TBP/Pol II at core promoters.In vitro binding studies confirmed that TAF7L forms complexes with both TBP and PPARγ.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular and Cell Biology , Howard Hughes Medical Institute, University of California, Berkeley , Berkeley , United States ; Li Ka Shing Center For Biomedical and Health Sciences, CIRM Center of Excellence, University of California, Berkeley , Berkeley , United States.

ABSTRACT
The diverse transcriptional mechanisms governing cellular differentiation and development of mammalian tissue remains poorly understood. Here we report that TAF7L, a paralogue of TFIID subunit TAF7, is enriched in adipocytes and white fat tissue (WAT) in mouse. Depletion of TAF7L reduced adipocyte-specific gene expression, compromised adipocyte differentiation, and WAT development as well. Ectopic expression of TAF7L in myoblasts reprograms these muscle precursors into adipocytes upon induction. Genome-wide mRNA-seq expression profiling and ChIP-seq binding studies confirmed that TAF7L is required for activating adipocyte-specific genes via a dual mechanism wherein it interacts with PPARγ at enhancers and TBP/Pol II at core promoters. In vitro binding studies confirmed that TAF7L forms complexes with both TBP and PPARγ. These findings suggest that TAF7L plays an integral role in adipocyte gene expression by targeting enhancers as a cofactor for PPARγ and promoters as a component of the core transcriptional machinery.DOI:http://dx.doi.org/10.7554/eLife.00170.001.

No MeSH data available.


Related in: MedlinePlus