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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 colocalizes and associates with PPARγ and TBP.(A) Two top motifs (motif 1 and motif 2) were found in TAF7L binding sites. Motif1 p<2e-20) matches with PPARγ binding motif and motif 2 p<3e-10) matches with C/EBPα binding motif. (B) Overlap of PPARγ peaks with TAF7L peaks in adipocytes, each circle represents the total peaks from ChIP-seq for a factor and the overlapped region represents the common binding peaks of the factors. (C) Similar as in (B); Pol II, TBP and TAF7L peaks from ChIP-seq overlap with each other in adipocytes. (D) Table showed the total peak numbers of each factor in adipocytes from ChIP-seq and the percentage of genome-wide peak overlapping between TAF7L and PPARγ, Pol II, TBP, IgG control. (E) FLAG tagged TAF7L, HA tagged PPARγ were overexpressed in 293T cells, immunoprecipitations were performed on both FLAG and HA antibodies and followed by Western blotting with FLAG and HA antibodies. (F) The same procedures were performed on FLAG tagged PPARγ and HA tagged TBP. (G) The same procedures were performed on FLAG tagged TAF7L and HA tagged TBP as in (E).DOI:http://dx.doi.org/10.7554/eLife.00170.013
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fig7: TAF7L colocalizes and associates with PPARγ and TBP.(A) Two top motifs (motif 1 and motif 2) were found in TAF7L binding sites. Motif1 p<2e-20) matches with PPARγ binding motif and motif 2 p<3e-10) matches with C/EBPα binding motif. (B) Overlap of PPARγ peaks with TAF7L peaks in adipocytes, each circle represents the total peaks from ChIP-seq for a factor and the overlapped region represents the common binding peaks of the factors. (C) Similar as in (B); Pol II, TBP and TAF7L peaks from ChIP-seq overlap with each other in adipocytes. (D) Table showed the total peak numbers of each factor in adipocytes from ChIP-seq and the percentage of genome-wide peak overlapping between TAF7L and PPARγ, Pol II, TBP, IgG control. (E) FLAG tagged TAF7L, HA tagged PPARγ were overexpressed in 293T cells, immunoprecipitations were performed on both FLAG and HA antibodies and followed by Western blotting with FLAG and HA antibodies. (F) The same procedures were performed on FLAG tagged PPARγ and HA tagged TBP. (G) The same procedures were performed on FLAG tagged TAF7L and HA tagged TBP as in (E).DOI:http://dx.doi.org/10.7554/eLife.00170.013

Mentions: By mapping the genomic binding sites, we found that both TBP and Pol II display greater than 63% occupancy at transcriptional start sites (TSS) of highly expressed genes in both undifferentiated C3H10T1/2 cells and adipocytes, consistent with their roles in mediating global and general transcription functions. Interestingly, comparing the binding regions of TAF7L, TBP and Pol II in adipocytes revealed that TAF7L only partially (30%) colocalizes with TBP and Pol II at a subset of promoters, while a greater proportion (45%) of TAF7L peaks localizes to enhancer regions where TBP and Pol II are generally not found (Figure 7B,C). This surprising finding suggests that TAF7L may function via additional mechanisms other than as a subunit of canonical TFIID in regulating adipocyte differentiation.10.7554/eLife.00170.013Figure 7.TAF7L colocalizes and associates with PPARγ and TBP.


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 colocalizes and associates with PPARγ and TBP.(A) Two top motifs (motif 1 and motif 2) were found in TAF7L binding sites. Motif1 p<2e-20) matches with PPARγ binding motif and motif 2 p<3e-10) matches with C/EBPα binding motif. (B) Overlap of PPARγ peaks with TAF7L peaks in adipocytes, each circle represents the total peaks from ChIP-seq for a factor and the overlapped region represents the common binding peaks of the factors. (C) Similar as in (B); Pol II, TBP and TAF7L peaks from ChIP-seq overlap with each other in adipocytes. (D) Table showed the total peak numbers of each factor in adipocytes from ChIP-seq and the percentage of genome-wide peak overlapping between TAF7L and PPARγ, Pol II, TBP, IgG control. (E) FLAG tagged TAF7L, HA tagged PPARγ were overexpressed in 293T cells, immunoprecipitations were performed on both FLAG and HA antibodies and followed by Western blotting with FLAG and HA antibodies. (F) The same procedures were performed on FLAG tagged PPARγ and HA tagged TBP. (G) The same procedures were performed on FLAG tagged TAF7L and HA tagged TBP as in (E).DOI:http://dx.doi.org/10.7554/eLife.00170.013
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig7: TAF7L colocalizes and associates with PPARγ and TBP.(A) Two top motifs (motif 1 and motif 2) were found in TAF7L binding sites. Motif1 p<2e-20) matches with PPARγ binding motif and motif 2 p<3e-10) matches with C/EBPα binding motif. (B) Overlap of PPARγ peaks with TAF7L peaks in adipocytes, each circle represents the total peaks from ChIP-seq for a factor and the overlapped region represents the common binding peaks of the factors. (C) Similar as in (B); Pol II, TBP and TAF7L peaks from ChIP-seq overlap with each other in adipocytes. (D) Table showed the total peak numbers of each factor in adipocytes from ChIP-seq and the percentage of genome-wide peak overlapping between TAF7L and PPARγ, Pol II, TBP, IgG control. (E) FLAG tagged TAF7L, HA tagged PPARγ were overexpressed in 293T cells, immunoprecipitations were performed on both FLAG and HA antibodies and followed by Western blotting with FLAG and HA antibodies. (F) The same procedures were performed on FLAG tagged PPARγ and HA tagged TBP. (G) The same procedures were performed on FLAG tagged TAF7L and HA tagged TBP as in (E).DOI:http://dx.doi.org/10.7554/eLife.00170.013
Mentions: By mapping the genomic binding sites, we found that both TBP and Pol II display greater than 63% occupancy at transcriptional start sites (TSS) of highly expressed genes in both undifferentiated C3H10T1/2 cells and adipocytes, consistent with their roles in mediating global and general transcription functions. Interestingly, comparing the binding regions of TAF7L, TBP and Pol II in adipocytes revealed that TAF7L only partially (30%) colocalizes with TBP and Pol II at a subset of promoters, while a greater proportion (45%) of TAF7L peaks localizes to enhancer regions where TBP and Pol II are generally not found (Figure 7B,C). This surprising finding suggests that TAF7L may function via additional mechanisms other than as a subunit of canonical TFIID in regulating adipocyte differentiation.10.7554/eLife.00170.013Figure 7.TAF7L colocalizes and associates with PPARγ and TBP.

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