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Yoshihiro Nakatani - One of the best experts on this subject based on the ideXlab platform.

  • Differential acetylation of Tat coordinates its interaction with the co-activators cyclin T1 and PCAF.
    The EMBO journal, 2002
    Co-Authors: Vanessa Brès, Yoshihiro Nakatani, Stéphane Emiliani, Monsef Benkirane, Kuan-teh Jeang, Hideaki Tagami, Jean-marie Peloponese, Erwan Loret, Rosemary Kiernan
    Abstract:

    The HIV-1 transactivator protein, Tat, is an atypical transcriptional activator that functions through binding, not to DNA, but to a short leader RNA, TAR. Although details of its functional mechanism are still unknown, emerging findings suggest that Tat serves primarily to adapt co-activator complexes such as p300, PCAF and P-TEFb to the HIV-1 long terminal repeat. Hence, an understanding of how Tat interacts with these cofactors is crucial. It has recently been shown that acetylation at a single lysine, residue 50, regulated the association of Tat with PCAF. Here, we report that in the absence of Tat acetylation, PCAF binds to amino acids 20-40 within Tat. Interestingly, acetylation of Tat at Lys28 abrogates Tat-PCAF interaction. Acetylation at Lys50 creates a new site for binding to PCAF and dictates the formation of a ternary complex of Tat-PCAF-P-TEFb. Thus, differential lysine acetylation of Tat coordinates the interactions with its co-activators, cyclin T1 and PCAF. Our results may help in understanding the ordered recruitment of Tat co-activators to the HIV-1 promoter.

  • distinct but overlapping roles of histone acetylase PCAF and of the closely related PCAF b gcn5 in mouse embryogenesis
    Proceedings of the National Academy of Sciences of the United States of America, 2000
    Co-Authors: Teruo Yamauchi, Jun Yamauchi, Takeshi Kuwata, Tomohiko Tamura, Tsuyoshi Yamashita, Nancy Bae, Heiner Westphal, Keiko Ozato, Yoshihiro Nakatani
    Abstract:

    PCAF plays a role in transcriptional activation, cell-cycle arrest, and cell differentiation in cultured cells. PCAF contributes to transcriptional activation by acetylating chromatin and transcription factors through its intrinsic histone acetylase activity. In this report, we present evidence for the in vivo function of PCAF and the closely related PCAF-B/GCN5. Mice lacking PCAF are developmentally normal without a distinct phenotype. In PCAF null-zygous mice, protein levels of PCAF-B/GCN5 are drastically elevated in lung and liver, where PCAF is abundantly expressed in wild-type mice, suggesting that PCAF-B/GCN5 functionally compensates for PCAF. In contrast, animals lacking PCAF-B/GCN5 die between days 9.5 and 11.5 of gestation. Normally, PCAF-B/GCN5 mRNA is expressed at high levels already by day 8, whereas PCAF mRNA is first detected on day 12.5, which may explain, in part, the distinct knockout phenotypes. These results provide evidence that PCAF and PCAF-B/GCN5 play distinct but functionally overlapping roles in embryogenesis.

  • PCAF interacts with tax and stimulates tax transactivation in a histone acetyltransferase independent manner
    Molecular and Cellular Biology, 1999
    Co-Authors: Hua Jiang, Louis R Schiltz, Yoshihiro Nakatani, Vasily Ogryzko, Cynthia A Pisemasison, John N Brady
    Abstract:

    Recent studies have shown that the p300/CREB binding protein (CBP)-associated factor (PCAF) is involved in transcriptional activation. PCAF activity has been shown strongly associated with histone acetyltransferase (HAT) activity. In this report, we present evidence for a HAT-independent transcription function that is activated in the presence of the human T-cell leukemia virus type 1 (HTLV-1) Tax protein. In vitro and in vivo GST-Tax pull-down and coimmunoprecipitation experiments demonstrate that there is a direct interaction between Tax and PCAF, independent of p300/CBP. PCAF can be recruited to the HTLV-1 Tax responsive element in the presence of Tax, and PCAF cooperates with Tax in vivo to activate transcription from the HTLV-1 LTR over 10-fold. Point mutations at Tax amino acid 318 (TaxS318A) or 319 to 320 (Tax M47), which have decreased or no activity on the HTLV-1 promoter, are defective for PCAF binding. Strikingly, the ability of PCAF to stimulate Tax transactivation is not solely dependent on the PCAF HAT domain. Two independent PCAF HAT mutants, which knock out acetyltransferase enzyme activity, activate Tax transactivation to approximately the same level as wild-type PCAF. In contrast, p300 stimulation of Tax transactivation is HAT dependent. These studies provide experimental evidence that PCAF contains a coactivator transcription function independent of the HAT activity on the viral long terminal repeat.

  • the histone acetylase PCAF is a phorbol ester inducible coactivator of the irf family that confers enhanced interferon responsiveness
    Molecular and Cellular Biology, 1999
    Co-Authors: Atsuko Masumi, Yoshihiro Nakatani, Iming Wang, Bruno Lefebvre, Xingjiao Yang, Keiko Ozato
    Abstract:

    Transcription factors of the interferon regulatory factor (IRF) family bind to the type I interferon (IFN)responsive element (ISRE) and activate transcription from IFN-inducible genes. To identify cofactors that associate with IRF proteins, DNA affinity binding assays were performed with nuclear extracts prepared from tissue culture cells. The results demonstrated that the endogenous IRFs bound to the ISRE are complexed with the histone acetylases, PCAF, GCN5, and p300/CREB binding protein and that histone acetylase activities are accumulated on the IRF-ISRE complexes. By testing recombinant proteins, we show that PCAF directly binds to some but not all members of the IRF family through distinct domains of the two proteins. This interaction was functionally significant, since transfection of PCAF strongly enhanced IRF-1- and IRF-2-dependent promoter activities. Further studies showed that expression of PCAF and other histone acetylases was markedly induced in U937 cells upon phorbol ester treatment, which led to increased recruitment of PCAF to the IRF-ISRE complexes. Coinciding with the induction of histone acetylases, phorbol ester markedly enhanced IFN-a-stimulated gene expression in U937 cells. Supporting the role for PCAF in conferring IFN responsiveness, transfection of PCAF into U937 cells led to a large increase in IFN-a-inducible promoter activity. These results demonstrate that PCAF is a phorbol ester-inducible coactivator of the IRF proteins which contributes to the establishment of type I IFN responsiveness.

  • overlapping but distinct patterns of histone acetylation by the human coactivators p300 and PCAF within nucleosomal substrates
    Journal of Biological Chemistry, 1999
    Co-Authors: Louis R Schiltz, Richard G Cook, David C Allis, Craig A Mizzen, Alex Vassilev, Yoshihiro Nakatani
    Abstract:

    Abstract A number of transcriptional coactivators possess intrinsic histone acetylase activity, providing a direct link between hyperacetylated chromatin and transcriptional activation. We have determined the core histone residues acetylated in vitro by recombinant p300 and PCAF within mononucleosomes. p300 specifically acetylates all sites of histones H2A and H2B known to be acetylated in bulk chromatin in vivo but preferentially acetylates lysines 14 and 18 of histone H3 and lysines 5 and 8 of histone H4. PCAF primarily acetylates lysine 14 of H3 but also less efficiently acetylates lysine 8 of H4. PCAF in its native form, which is present in a stable multimeric protein complex lacking p300/CBP, primarily acetylates H3 to a monoacetylated form, suggesting that PCAF-associated polypeptides do not alter the substrate specificity. These distinct patterns of acetylation by the p300 and PCAF may contribute to their differential roles in transcriptional regulation.

Xiangjiao Yang - One of the best experts on this subject based on the ideXlab platform.

  • PCAF is a coactivator for p73 mediated transactivation
    Oncogene, 2003
    Co-Authors: Lisa Y Zhao, Xiangjiao Yang, Yue Liu, Nicholas Bertos, Daiqing Liao
    Abstract:

    The tumor suppressor p53-related p73 shares significant amino-acid sequence identity with p53. Like p53, p73 recognizes canonical p53 DNA-binding sites and activates p53-responsive target genes and induces apoptosis. Moreover, transcription coactivator p300/CBP binds to and coactivates with both p53 and p73 in stimulating the expression of their target genes. Here, we report that coactivator PCAF binds to p73. The N-terminal transactivation domain (TAD) and the conserved oligomerization domain (OD) of p73 are both required for its interaction with PCAF. Conversely, PCAF's HAT-domain is required for and both the N-terminal region and Bromo domain enhance binding of PCAF to p73. Significantly, PCAF stimulates p73-mediated transactivation, and binding of PCAF to p73 is necessary for p73's transactivation activity. PCAF-specific siRNA dramatically reduces p73-mediated transactivation. Stimulation of p73-mediated transactivation by PCAF requires the HAT domain of PCAF and the p53-binding site within the p21 promoter. In vivo, coexpression of wild-type, but not HAT-deficient PCAF with p73beta markedly increases p21 expression. Furthermore, cotransfection of PCAF and p73 leads to increased apoptosis and reduced colony formation. Collectively, these data suggest that p73 recruit PCAF to specific promoters to activate the transcription of p73 target genes.

  • mdm2 inhibits PCAF p300 creb binding protein associated factor mediated p53 acetylation
    Journal of Biological Chemistry, 2002
    Co-Authors: Yetao Jin, Shelya X Zeng, Mu Shui Dai, Xiangjiao Yang
    Abstract:

    Abstract Our previous study shows that MDM2, a negative feedback regulator of the tumor suppressor p53, inhibits p300-mediated p53 acetylation. Because PCAF (p300/CREB-binding protein-associated factor) also acetylates and activates p53 after DNA damage, in this study we have examined the effect of MDM2 on PCAF-mediated p53 acetylation. We have found that MDM2 inhibited p53 acetylation by PCAF in vitro. In addition, when overexpressed, MDM2 inhibited PCAF-mediated p53 acetylation in cells. MDM2 interacted with PCAF both in vitro and in cells, as assessed using GST fusion protein interaction and immunoprecipitation assays, respectively. Consistent with the above results, MDM2 significantly repressed the activation of p53 transcriptional activity by PCAF without apparently affecting the level of p53. In addition, MDM2 co-resided with p53 at the p53-responsivemdm2 and p21waf1/cip1 promoters, inhibiting expression of the endogenous p21waf1/cip1. These results demonstrate that MDM2 can inhibit PCAF-mediated p53 acetylation and activation.

  • adenovirus e1b 55 kilodalton oncoprotein inhibits p53 acetylation by PCAF
    Molecular and Cellular Biology, 2000
    Co-Authors: Yue Liu, Xiangjiao Yang, April L Colosimo, Daiqing Liao
    Abstract:

    The adenovirus E1B 55-kDa protein binds to cellular tumor suppressor p53 and inactivates its transcriptional transactivation function. p53 transactivation activity is dependent upon its ability to bind to specific DNA sequences near the promoters of its target genes. It was shown recently that p53 is acetylated by transcriptional coactivators p300, CREB bidning protein (CBP), and PCAF and that acetylation of p53 by these proteins enhances p53 sequence-specific DNA binding. Here we show that the E1B 55-kDa protein specifically inhibits p53 acetylation by PCAF in vivo and in vitro, while acetylation of histones and PCAF autoacetylation is not affected. Furthermore, the DNA-binding activity of p53 is diminished in cells expressing the E1B 55-kDa protein. PCAF binds to the E1B 55-kDa protein and to a region near the C terminus of p53 encompassing Lys-320, the specific PCAF acetylation site. We further show that the E1B 55-kDa protein interferes with the physical interaction between PCAF and p53, suggesting that the E1B 55-kDa protein inhibits PCAF acetylase function on p53 by preventing enzyme-substrate interaction. These results underscore the importance of p53 acetylation for its function and suggest that inhibition of p53 acetylation by viral oncoproteins prevent its activation, thereby contributing to viral transformation.

  • histone like tafs within the PCAF histone acetylase complex
    Cell, 1998
    Co-Authors: Vasily Ogryzko, Louis R Schiltz, Xiangjiao Yang, Bruce H Howard, Tomohiro Kotani, Xiaolong Zhang, Tazuko Howard, Jun Qin, Yoshihiro Nakatani
    Abstract:

    Abstract PCAF histone acetylase plays a role in regulation of transcription, cell cycle progression, and differentiation. Here, we show that PCAF is found in a complex consisting of more than 20 distinct polypeptides. Strikingly, some polypeptides are identical to TBP-associated factors (TAFs), which are subunits of TFIID. Like TFIID, histone fold–containing factors are present within the PCAF complex. The histone H3– and H2B–like subunits within the PCAF complex are identical to those within TFIID, namely, hTAF II 31 and hTAF II 20/15, respectively. The PCAF complex has a novel histone H4–like subunit with similarity to hTAF II 80 that interacts with the histone H3–like domain of hTAF II 31. Moreover, the PCAF complex has a novel subunit with WD40 repeats having a similarity to hTAF II 100.

  • the histone acetylase PCAF is a nuclear receptor coactivator
    Genes & Development, 1998
    Co-Authors: Jorge C G Blanco, Yoshihiro Nakatani, Xiangjiao Yang, Saverio Minucci, Kristen K Walker, Hongwu Chen, Ronald M Evans, Keiko Ozato
    Abstract:

    Whereas the histone acetylase PCAF has been suggested to be part of a coactivator complex mediating transcriptional activation by the nuclear hormone receptors, the physical and functional interactions between nuclear receptors and PCAF have remained unclear. Our efforts to clarify these relationships have revealed two novel properties of nuclear receptors. First, we demonstrate that the RXR/RAR heterodimer directly recruits PCAF from mammalian cell extracts in a ligand-dependent manner and that increased expression of PCAF leads to enhanced retinoid-responsive transcription. Second, we demonstrate that, in vitro, PCAF directly associates with the DNA-binding domain of nuclear receptors, independently of p300/CBP binding, therefore defining a novel cofactor interaction surface. Furthermore, our results show that dissociation of corepressors enables ligand-dependent PCAF binding to the receptors. This observation illuminates how a ligand-dependent receptor function can be propagated to regions outside the ligand-binding domain itself. On the basis of these observations, we suggest that PCAF may play a more central role in nuclear receptor function than previously anticipated.

Oriol Bachs - One of the best experts on this subject based on the ideXlab platform.

  • p27Kip1, PCAF and PAX5 cooperate in the transcriptional regulation of specific target genes.
    Nucleic Acids Research, 2017
    Co-Authors: Anna Perearnau, Serena Orlando, Abul B.m.m.k. Islam, Jonatan Martinez, Albert Jordan, Rosa Aligué, Edurne Gallastegui, Maria Jesus Pujol, Anna Bigas, Oriol Bachs
    Abstract:

    : The cyclin-dependent kinase inhibitor p27Kip1 (p27) also behaves as a transcriptional repressor. Data showing that the p300/CBP-associated factor (PCAF) acetylates p27 inducing its degradation suggested that PCAF and p27 could collaborate in the regulation of transcription. However, this possibility remained to be explored. We analyzed here the transcriptional programs regulated by PCAF and p27 in the colon cancer cell line HCT116 by chromatin immunoprecipitation sequencing (ChIP-seq). We identified 269 protein-encoding genes that contain both p27 and PCAF binding sites being the majority of these sites different for PCAF and p27. PCAF or p27 knock down revealed that both regulate the expression of these genes, PCAF as an activator and p27 as a repressor. The double knock down of PCAF and p27 strongly reduced their expression indicating that the activating role of PCAF overrides the repressive effect of p27. We also observed that the transcription factor Pax5 interacts with both p27 and PCAF and that the knock down of Pax5 induces the expression of p27/PCAF target genes indicating that it also participates in the transcriptional regulation mediated by p27/PCAF. In summary, we report here a previously unknown mechanism of transcriptional regulation mediated by p27, Pax5 and PCAF.

  • PCAF regulates the stability of the transcriptional regulator and cyclin dependent kinase inhibitor p27kip1
    Nucleic Acids Research, 2012
    Co-Authors: Maria Perezluna, Anna Perearnau, Maria Jesus Pujol, Marta Aguasca, Joan Serratosa, Marian A Martinezbalbas, Oriol Bachs
    Abstract:

    P27(Kip1) (p27) is a member of the Cip/Kip family of cyclin-dependent kinase inhibitors. Recently, a new function of p27 as transcriptional regulator has been reported. It has been shown that p27 regulates the expression of target genes mostly involved in splicing, cell cycle, respiration and translation. We report here that p27 directly binds to the transcriptional coactivator PCAF by a region including amino acids 91-120. PCAF associates with p27 through its catalytic domain and acetylates p27 at lysine 100. Our data showed that overexpression of PCAF induces the degradation of p27 whereas in contrast, the knockdown of PCAF stabilizes the protein. A p27 mutant in which K100 was substituted by arginine (p27-K100R) cannot be acetylated by PCAF and has a half-life much higher than that of p27WT. Moreover, p27-K100R remains stable along cell-cycle progression. Ubiquitylation assays and the use of proteasome inhibitors indicate that PCAF induces p27 degradation via proteasome. We also observed that knockdown of skp2 did not affect the PCAF induced degradation of p27. In conclusion, our data suggest that the p27 acetylation by PCAF regulates its stability.

  • the transcriptional co activator PCAF regulates cdk2 activity
    Nucleic Acids Research, 2009
    Co-Authors: Francesca Mateo, Maria Jesus Pujol, Marian A Martinezbalbas, Miriam Vidallaliena, Nuria Canela, Annalisa Zecchin, Neus Agell, Mauro Giacca, Oriol Bachs
    Abstract:

    Cyclin dependent kinases (cdks) regulate cell cycle progression and transcription. We report here that the transcriptional co-activator PCAF directly interacts with cdk2. This interaction is mainly produced during S and G2/M phases of the cell cycle. As a consequence of this association, PCAF inhibits the activity of cyclin/cdk2 complexes. This effect is specific for cdk2 because PCAF does not inhibit either cyclin D3/cdk6 or cyclin B/cdk1 activities. The inhibition is neither competitive with ATP, nor with the substrate histone H1 suggesting that somehow PCAF disturbs cyclin/cdk2 complexes. We also demonstrate that overexpression of PCAF in the cells inhibits cdk2 activity and arrests cell cycle progression at S and G2/M. This blockade is dependent on cdk2 because it is rescued by the simultaneous overexpression of this kinase. Moreover, we also observed that PCAF acetylates cdk2 at lysine 33. As this lysine is essential for the interaction with ATP, acetylation of this residue inhibits cdk2 activity. Thus, we report here that PCAF inhibits cyclin/cdk2 activity by two different mechanisms: (i) by somehow affecting cyclin/ cdk2 interaction and (ii) by acetylating K33 at the catalytic pocket of cdk2. These findings identify a previously unknown mechanism that regulates cdk2 activity.

Milan Mrksich - One of the best experts on this subject based on the ideXlab platform.

  • acetyltransferase p300 cbp associated factor PCAF regulates crosstalk dependent acetylation of histone h3 by distal site recognition
    ACS Chemical Biology, 2015
    Co-Authors: James R. Kornacki, Andreea D. Stuparu, Milan Mrksich
    Abstract:

    Epigenetic regulation is directed, in part, by the correlated placement of histone post-translational modifications, but the mechanisms controlling correlated modifications are incompletely understood. Correlations arise from crosstalk among modifications and are frequently attributed to protein-protein interactions that recruit enzymes to existing histone modifications. Here we report the use of a peptide array to discover acetyltransferase-mediated crosstalks. We show that p300/CBP associated factor (PCAF)/GCN5 activity depends on the presence of a distal arginine residue of its histone H3 substrate. Modifications to H3 Arg8 decrease PCAF acetylation of H3 Lys14, and kinetic data indicate that arginine citrullination has the strongest effect in decreasing acetylation. Mutagenesis experiments demonstrate that PCAF specifically interprets H3 Arg8 modifications through interaction with residue Tyr640 on the surface of its catalytic domain, and this interaction regulates Lys14 acetylation by substrate discrimination. PCAF discriminates modified peptides as well as semisynthetic proteins and reconstituted nucleosomes bearing Arg8 modifications. Together, this work describes a method for systematically mapping crosstalks and illustrates its application to the discovery and elucidation of novel PCAF crosstalks.

  • Acetyltransferase p300/CBP Associated Factor (PCAF) Regulates Crosstalk-Dependent Acetylation of Histone H3 by Distal Site Recognition
    2015
    Co-Authors: James R. Kornacki, Andreea D. Stuparu, Milan Mrksich
    Abstract:

    Epigenetic regulation is directed, in part, by the correlated placement of histone post-translational modifications, but the mechanisms controlling correlated modifications are incompletely understood. Correlations arise from crosstalk among modifications and are frequently attributed to protein–protein interactions that recruit enzymes to existing histone modifications. Here we report the use of a peptide array to discover acetyltransferase-mediated crosstalks. We show that p300/CBP associated factor (PCAF)/GCN5 activity depends on the presence of a distal arginine residue of its histone H3 substrate. Modifications to H3 Arg8 decrease PCAF acetylation of H3 Lys14, and kinetic data indicate that arginine citrullination has the strongest effect in decreasing acetylation. Mutagenesis experiments demonstrate that PCAF specifically interprets H3 Arg8 modifications through interaction with residue Tyr640 on the surface of its catalytic domain, and this interaction regulates Lys14 acetylation by substrate discrimination. PCAF discriminates modified peptides as well as semisynthetic proteins and reconstituted nucleosomes bearing Arg8 modifications. Together, this work describes a method for systematically mapping crosstalks and illustrates its application to the discovery and elucidation of novel PCAF crosstalks

Nagashayana Natesh - One of the best experts on this subject based on the ideXlab platform.

  • Probing p300/CBP Associated Factor (PCAF)-Dependent Pathways with a Small Molecule Inhibitor
    2016
    Co-Authors: Rahul Modak, Jeelan Basha, Narendra Bharathy, Koustav Maity, Pushpak Mizar, Akshay V. Bhat, Madavan Vasudevan, Vinay Kumar Rao, Wai Kay Kok, Nagashayana Natesh
    Abstract:

    PCAF (KAT2B) belongs to the GNAT family of lysine acetyltransferases (KAT) and specifically acetylates the histone H3K9 residue and several nonhistone proteins. PCAF is also a transcriptional coactivator. Due to the lack of a PCAF KAT-specific small molecule inhibitor, the exclusive role of the acetyltransferase activity of PCAF is not well understood. Here, we report that a natural compound of the hydroxybenzoquinone class, embelin, specifically inhibits H3Lys9 acetylation in mice and inhibits recombinant PCAF-mediated acetylation with near complete specificity in vitro. Furthermore, using embelin, we have identified the gene networks that are regulated by PCAF during muscle differentiation, further highlighting the broader regulatory functions of PCAF in muscle differentiation in addition to the regulation via MyoD acetylation

  • probing p300 cbp associated factor PCAF dependent pathways with a small molecule inhibitor
    ACS Chemical Biology, 2013
    Co-Authors: Rahul Modak, Jeelan Basha, Narendra Bharathy, Koustav Maity, Pushpak Mizar, Madavan Vasudevan, Vinay Kumar Rao, Wai Kay Kok, Akshay Bhat, Nagashayana Natesh
    Abstract:

    PCAF (KAT2B) belongs to the GNAT family of lysine acetyltransferases (KAT) and specifically acetylates the histone H3K9 residue and several nonhistone proteins. PCAF is also a transcriptional coactivator. Due to the lack of a PCAF KAT-specific small molecule inhibitor, the exclusive role of the acetyltransferase activity of PCAF is not well understood. Here, we report that a natural compound of the hydroxybenzoquinone class, embelin, specifically inhibits H3Lys9 acetylation in mice and inhibits recombinant PCAF-mediated acetylation with near complete specificity in vitro. Furthermore, using embelin, we have identified the gene networks that are regulated by PCAF during muscle differentiation, further highlighting the broader regulatory functions of PCAF in muscle differentiation in addition to the regulation via MyoD acetylation.