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The 19S proteasome subcomplex promotes the targeting of NuA4 HAT to the promoters of ribosomal protein genes to facilitate the recruitment of TFIID for transcriptional initiation in vivo.

Uprety B, Lahudkar S, Malik S, Bhaumik SR - Nucleic Acids Res. (2011)

Bottom Line: These observations support that the 19S proteasome subcomplex enhances the targeting of co-activator at the TFIID-dependent promoter.Such an enhanced targeting of NuA4 HAT (histone acetyltransferase) promotes the recruitment of the TFIID complex for transcriptional initiation.Collectively, our data demonstrate that the 19S proteasome subcomplex enhances the targeting of NuA4 HAT to activator Rap1p at the promoters of ribosomal protein genes to facilitate the recruitment of TFIID for transcriptional stimulation, hence providing a new role of the 19S proteasome subcomplex in establishing a specific regulatory network at the TFIID-dependent promoter for productive transcriptional initiation in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Southern Illinois University-School of Medicine, Carbondale, IL 62901, USA.

ABSTRACT
Previous studies have implicated SAGA (Spt-Ada-Gcn5-acetyltransferase) and TFIID (Transcription factor-IID)-dependent mechanisms of transcriptional activation in yeast. SAGA-dependent transcriptional activation is further regulated by the 19S proteasome subcomplex. However, the role of the 19S proteasome subcomplex in transcriptional activation of the TFIID-dependent genes has not been elucidated. Therefore, we have performed a series of chromatin immunoprecipitation, mutational and transcriptional analyses at the TFIID-dependent ribosomal protein genes such as RPS5, RPL2B and RPS11B. We find that the 19S proteasome subcomplex is recruited to the promoters of these ribosomal protein genes, and promotes the association of NuA4 (Nucleosome acetyltransferase of histone H4) co-activator, but not activator Rap1p (repressor-activator protein 1). These observations support that the 19S proteasome subcomplex enhances the targeting of co-activator at the TFIID-dependent promoter. Such an enhanced targeting of NuA4 HAT (histone acetyltransferase) promotes the recruitment of the TFIID complex for transcriptional initiation. Collectively, our data demonstrate that the 19S proteasome subcomplex enhances the targeting of NuA4 HAT to activator Rap1p at the promoters of ribosomal protein genes to facilitate the recruitment of TFIID for transcriptional stimulation, hence providing a new role of the 19S proteasome subcomplex in establishing a specific regulatory network at the TFIID-dependent promoter for productive transcriptional initiation in vivo.

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NuA4 HAT is required for recruitment of the TFIID complex to the RPS5 promoter. (A) Analysis of the recruitment of TBP and TAFs components of the TFIID complex to the RPS5 core promoter in the esa1-ts mutant and its isogenic wild-type equivalent. Yeast cells were grown as in Figure 3C, but Esa1p was inactivated for 1 h at the non-permissive temperature. Immunoprecipitation was performed using anti-TBP, anti-TAF1 and anti-TAF12 antibodies against TBP, TAF1 and TAF12 (obtained from the Green laboratory; 13). (B) RT–PCR analysis of RPS5 and ACT1 transcripts in the esa1-ts mutant and its isogenic wild-type equivalent following 1 h ts inactivation at the non-permissive temperature.
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gkr977-F4: NuA4 HAT is required for recruitment of the TFIID complex to the RPS5 promoter. (A) Analysis of the recruitment of TBP and TAFs components of the TFIID complex to the RPS5 core promoter in the esa1-ts mutant and its isogenic wild-type equivalent. Yeast cells were grown as in Figure 3C, but Esa1p was inactivated for 1 h at the non-permissive temperature. Immunoprecipitation was performed using anti-TBP, anti-TAF1 and anti-TAF12 antibodies against TBP, TAF1 and TAF12 (obtained from the Green laboratory; 13). (B) RT–PCR analysis of RPS5 and ACT1 transcripts in the esa1-ts mutant and its isogenic wild-type equivalent following 1 h ts inactivation at the non-permissive temperature.

Mentions: To determine whether, like the 19S base, NuA4 HAT also facilitates the recruitment of TFIID, we analyzed the association of TBP and TAFs components (TAF1 and TAF12) of the TFIID complex with the RPS5 core promoter in the wild-type and ts mutant strains of the Esa1p HAT component of NuA4. We find that the recruitment of the TFIID complex to the RPS5 core promoter was significantly impaired in the esa1-ts mutant strain as compared with the wild-type equivalent (Figure 4A). Such an impaired recruitment of TFIID in the esa1-ts mutant significantly lowered the transcription of RPS5 (Figure 4B). As a control, we have used ACT1, since its transcription is not dependent on NuA4 HAT (55). As expected, we find that transcription of ACT1 was not altered in the esa1-ts mutant strain (Figure 4B). As a whole, our data demonstrate that NuA4 HAT enhances the recruitment of TFIID (and hence transcription) at the core promoter of the ribosomal protein gene, RPS5. Consistently, previous studies (55,56) have also implicated the role of NuA4 HAT in stimulation of transcription of the ribosomal protein genes. However, the mechanism of such transcriptional stimulation was not known. Here, we show that NuA4 HAT promotes transcription of the ribosomal protein gene, RPS5, by enhancing the recruitment of the TFIID complex. Further, NuA4 HAT has been shown to be targeted to the promoters of ribosomal protein genes by the activator Rap1p (55). Therefore, the recruitment of Rap1p is essential for association of TFIID with promoter. Indeed, previous studies (13,15,16) have demonstrated the role of Rap1p in recruitment of TFIID. Here, we demonstrate that like Rap1p, NuA4 HAT and 19S base are both required to facilitate the recruitment of TFIID for transcriptional initiation of RPS5.Figure 4.


The 19S proteasome subcomplex promotes the targeting of NuA4 HAT to the promoters of ribosomal protein genes to facilitate the recruitment of TFIID for transcriptional initiation in vivo.

Uprety B, Lahudkar S, Malik S, Bhaumik SR - Nucleic Acids Res. (2011)

NuA4 HAT is required for recruitment of the TFIID complex to the RPS5 promoter. (A) Analysis of the recruitment of TBP and TAFs components of the TFIID complex to the RPS5 core promoter in the esa1-ts mutant and its isogenic wild-type equivalent. Yeast cells were grown as in Figure 3C, but Esa1p was inactivated for 1 h at the non-permissive temperature. Immunoprecipitation was performed using anti-TBP, anti-TAF1 and anti-TAF12 antibodies against TBP, TAF1 and TAF12 (obtained from the Green laboratory; 13). (B) RT–PCR analysis of RPS5 and ACT1 transcripts in the esa1-ts mutant and its isogenic wild-type equivalent following 1 h ts inactivation at the non-permissive temperature.
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Show All Figures
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gkr977-F4: NuA4 HAT is required for recruitment of the TFIID complex to the RPS5 promoter. (A) Analysis of the recruitment of TBP and TAFs components of the TFIID complex to the RPS5 core promoter in the esa1-ts mutant and its isogenic wild-type equivalent. Yeast cells were grown as in Figure 3C, but Esa1p was inactivated for 1 h at the non-permissive temperature. Immunoprecipitation was performed using anti-TBP, anti-TAF1 and anti-TAF12 antibodies against TBP, TAF1 and TAF12 (obtained from the Green laboratory; 13). (B) RT–PCR analysis of RPS5 and ACT1 transcripts in the esa1-ts mutant and its isogenic wild-type equivalent following 1 h ts inactivation at the non-permissive temperature.
Mentions: To determine whether, like the 19S base, NuA4 HAT also facilitates the recruitment of TFIID, we analyzed the association of TBP and TAFs components (TAF1 and TAF12) of the TFIID complex with the RPS5 core promoter in the wild-type and ts mutant strains of the Esa1p HAT component of NuA4. We find that the recruitment of the TFIID complex to the RPS5 core promoter was significantly impaired in the esa1-ts mutant strain as compared with the wild-type equivalent (Figure 4A). Such an impaired recruitment of TFIID in the esa1-ts mutant significantly lowered the transcription of RPS5 (Figure 4B). As a control, we have used ACT1, since its transcription is not dependent on NuA4 HAT (55). As expected, we find that transcription of ACT1 was not altered in the esa1-ts mutant strain (Figure 4B). As a whole, our data demonstrate that NuA4 HAT enhances the recruitment of TFIID (and hence transcription) at the core promoter of the ribosomal protein gene, RPS5. Consistently, previous studies (55,56) have also implicated the role of NuA4 HAT in stimulation of transcription of the ribosomal protein genes. However, the mechanism of such transcriptional stimulation was not known. Here, we show that NuA4 HAT promotes transcription of the ribosomal protein gene, RPS5, by enhancing the recruitment of the TFIID complex. Further, NuA4 HAT has been shown to be targeted to the promoters of ribosomal protein genes by the activator Rap1p (55). Therefore, the recruitment of Rap1p is essential for association of TFIID with promoter. Indeed, previous studies (13,15,16) have demonstrated the role of Rap1p in recruitment of TFIID. Here, we demonstrate that like Rap1p, NuA4 HAT and 19S base are both required to facilitate the recruitment of TFIID for transcriptional initiation of RPS5.Figure 4.

Bottom Line: These observations support that the 19S proteasome subcomplex enhances the targeting of co-activator at the TFIID-dependent promoter.Such an enhanced targeting of NuA4 HAT (histone acetyltransferase) promotes the recruitment of the TFIID complex for transcriptional initiation.Collectively, our data demonstrate that the 19S proteasome subcomplex enhances the targeting of NuA4 HAT to activator Rap1p at the promoters of ribosomal protein genes to facilitate the recruitment of TFIID for transcriptional stimulation, hence providing a new role of the 19S proteasome subcomplex in establishing a specific regulatory network at the TFIID-dependent promoter for productive transcriptional initiation in vivo.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Southern Illinois University-School of Medicine, Carbondale, IL 62901, USA.

ABSTRACT
Previous studies have implicated SAGA (Spt-Ada-Gcn5-acetyltransferase) and TFIID (Transcription factor-IID)-dependent mechanisms of transcriptional activation in yeast. SAGA-dependent transcriptional activation is further regulated by the 19S proteasome subcomplex. However, the role of the 19S proteasome subcomplex in transcriptional activation of the TFIID-dependent genes has not been elucidated. Therefore, we have performed a series of chromatin immunoprecipitation, mutational and transcriptional analyses at the TFIID-dependent ribosomal protein genes such as RPS5, RPL2B and RPS11B. We find that the 19S proteasome subcomplex is recruited to the promoters of these ribosomal protein genes, and promotes the association of NuA4 (Nucleosome acetyltransferase of histone H4) co-activator, but not activator Rap1p (repressor-activator protein 1). These observations support that the 19S proteasome subcomplex enhances the targeting of co-activator at the TFIID-dependent promoter. Such an enhanced targeting of NuA4 HAT (histone acetyltransferase) promotes the recruitment of the TFIID complex for transcriptional initiation. Collectively, our data demonstrate that the 19S proteasome subcomplex enhances the targeting of NuA4 HAT to activator Rap1p at the promoters of ribosomal protein genes to facilitate the recruitment of TFIID for transcriptional stimulation, hence providing a new role of the 19S proteasome subcomplex in establishing a specific regulatory network at the TFIID-dependent promoter for productive transcriptional initiation in vivo.

Show MeSH