Differences and similarities in recognition of co-factors by Taf14

Taf14 is a subunit of multiple fundamental complexes implicated in transcriptional regulation and DNA damage repair in yeast cells. Here, we investigate the association of Taf14 with the consensus sequence present in other subunits of these complexes and describe the mechanistic features that affect this association. We demonstrate that the precise molecular mechanisms and biological outcomes underlying the Taf14 interactions depend on the accessibility of binding interfaces, the ability to recognize other ligands, and a degree of sensitivity to temperature and chemical and osmotic stresses. Our findings aid in a better understanding of how the distribution of Taf14 among the complexes is mediated.

BcTaf14 regulates growth and development, virulence, and stress responses in the phytopathogenic fungus Botrytis cinerea

TATA box-binding protein (TBP)-associated factor 14 (Taf14), a transcription-associated factor containing a conserved YEATS domain and an extra-terminal (ET) domain, is a multifunctional protein in Saccharomyces cerevisiae. However, the role of Taf14 in filamentous phytopathogenic fungi is not well understood. In this study, the homologue of ScTaf14 in Botrytis cinerea (named BcTaf14), a destructive phytopathogen causing grey mould, was investigated. The BcTaf14 deletion strain (ΔBcTaf14) showed pleiotropic defects, including slow growth, abnormal colony morphology, reduced conidiation, abnormal conidial morphology, reduced virulence, and altered responses to various stresses. The ΔBcTaf14 strain also exhibited differential expression of numerous genes compared to the wild-type strain. BcTaf14 could interact with the crotonylated H3K9 peptide, and mutation of two key sites (G80 and W81) in the YEATS domain disrupted this interaction. The mutation of G80 and W81 affected the regulatory effect of BcTaf14 on mycelial growth and virulence but did not affect the production and morphology of conidia. The absence of the ET domain at the C-terminus rendered BcTaf14 unable to localize to the nucleus, and the defects of ΔBcTaf14 were not recovered to wild-type levels when BcTaf14 without the ET domain was expressed. Our results provide insight into the regulatory roles of BcTaf14 and its two conserved domains in B. cinerea and will be helpful for understanding the function of the Taf14 protein in plant-pathogenic fungi.

Transcriptional regulator Taf14 binds DNA and is required for the function of transcription factor TFIID in the absence of histone H2A.Z

The transcriptional regulator Taf14 is a component of multiple protein complexes involved in transcription initiation and chromatin remodeling in yeast cells. Although Taf14 is not required for cell viability, it becomes essential in conditions where the formation of the transcription preinitiation complex is hampered. The specific role of Taf14 in mediating transcription initiation and preinitiation complex formation is unclear. Here, we explored its role in the general transcription factor IID by mapping Taf14 genetic and proteomic interactions and found that it was needed for the function of the complex if Htz1, the yeast homolog of histone H2A.Z, was absent from chromatin. Dissecting the functional domains of Taf14 revealed that the linker region between the YEATS and ET domains was required for cell viability in the absence of Htz1 protein. We further show that the linker region of Taf14 interacts with DNA. We propose that providing additional DNA binding capacity might be a general role of Taf14 in the recruitment of protein complexes to DNA and chromatin.

Taf14 is required for the stabilization of transcription pre-initiation complex in Saccharomyces cerevisiae

Background

The YEATS domain is a highly conserved protein structure that interacts with acetylated and crotonylated lysine residues in N-terminal tails of histones. The budding yeast genome encodes three YEATS domain proteins (Taf14, Yaf9, and Sas5) that are all the subunits of different complexes involved in histone acetylation, gene transcription, and chromatin remodeling. As the strains deficient in all these three genes are inviable, it has been proposed that the YEATS domain is essential in yeast. In this study we investigate in more detail the requirement of YEATS domain proteins for yeast survival and the possible roles of Taf14 YEATS domain in the regulation of gene transcription.

Results

We found that YEATS domains are not essential for the survival of Saccharomyces cerevisiae cells. Although the full deletion of all YEATS proteins is lethal in yeast, we show that the viability of cells can be restored by the expression of the YEATS-less version of Taf14 protein. We also explore the in vivo functions of Taf14 protein and show that the primary role of its YEATS domain is to stabilize the transcription pre-initiation complex (PIC). Our results indicate that Taf14-mediated interactions become crucial for PIC formation in rpb9Δ cells, where the recruitment of TFIIF to the PIC is hampered. Although H3 K9 residue has been identified as the interaction site of the Taf14 YEATS domain in vitro, we found that it is not the only interaction target in vivo.

Conclusions

Lethality of YEATS-deficient cells can be rescued by the expression of truncated Taf14 protein lacking the entire YEATS domain, indicating that the YEATS domains are not required for cell survival. The YEATS domain of Taf14 participates in PIC stabilization and acetylated/crotonylated H3K9 is not the critical target of the Taf14 YEATS domain in vivo.

The YEATS Domain Histone Crotonylation Readers Control Virulence-Related Biology of a Major Human Pathogen

Identification of multiple histone acylations diversifies transcriptional control by metabolism, but their functions are incompletely defined. Here we report evidence of histone crotonylation in the human fungal pathogen Candida albicans. We define the enzymes that regulate crotonylation and show its dynamic control by environmental signals: carbon sources, the short-chain fatty acids butyrate and crotonate, and cell wall stress. Crotonate regulates stress-responsive transcription and rescues C. albicans from cell wall stress, indicating broad impact on cell biology. The YEATS domain crotonylation readers Taf14 and Yaf9 are required for C. albicans virulence, and Taf14 controls gene expression, stress resistance, and invasive growth via its chromatin reader function. Blocking the Taf14 C terminus with a tag reduced virulence, suggesting that inhibiting Taf14 interactions with chromatin regulators impairs function. Our findings shed light on the regulation of histone crotonylation and the functions of the YEATS proteins in eukaryotic pathogen biology and fungal infections.

The essential role of acetyllysine binding by the YEATS domain in transcriptional regulation

The YEATS domains of AF9 and Taf14 have recently been found to recognize the histone H3K9ac modification. In this commentary, we discuss the mechanistic and biological implications of this interaction. We compare structures of the YEATS-H3K9ac complexes the highlighting a novel mechanism for the acetyllysine recognition through the aromatic cage. We also summarize the latest findings underscoring a critical role of the acetyllysine binding function of AF9 and Taf14 in transcriptional regulation and DNA repair.

The C Terminus of the RNA Polymerase II Transcription Factor IID (TFIID) Subunit Taf2 Mediates Stable Association of Subunit Taf14 into the Yeast TFIID Complex

The evolutionarily conserved RNA polymerase II transcription factor D (TFIID) complex is composed of TATA box-binding protein (TBP) and 13 TBP-associated factors (Tafs). The mechanisms by which many Taf subunits contribute to the essential function of TFIID are only poorly understood. To address this gap in knowledge, we present the results of a molecular genetic dissection of the TFIID subunit Taf2. Through systematic site-directed mutagenesis, we have discovered 12 taf2 temperature-sensitive (ts) alleles. Two of these alleles display growth defects that can be strongly suppressed by overexpression of the yeast-specific TFIID subunit TAF14 but not by overexpression of any other TFIID subunit. In Saccharomyces cerevisiae, Taf14 is also a constituent of six other transcription-related complexes, making interpretation of its role in each of these complexes difficult. Although Taf14 is not conserved as a TFIID subunit in metazoans, it is conserved through its chromatin-binding YEATS domain. Based on the Taf2-Taf14 genetic interaction, we demonstrate that Taf2 and Taf14 directly interact and mapped the Taf2-Taf14 interaction domains. We used this information to identify a Taf2 separation-of-function variant (Taf2-ΔC). Although Taf2-ΔC no longer interacts with Taf14 in vivo or in vitro, it stably incorporates into the TFIID complex. In addition, purified Taf2-ΔC mutant TFIID is devoid of Taf14, making this variant a powerful reagent for determining the role of Taf14 in TFIID function. Furthermore, we characterized the mechanism through which Taf14 suppresses taf2^ts alleles, shedding light on how Taf2-Taf14 interaction contributes to TFIID complex organization and identifying a potential role for Taf14 in mediating TFIID-chromatin interactions.

Association of Taf14 with acetylated histone H3 directs gene transcription and the DNA damage response

The YEATS domain, found in a number of chromatin-associated proteins, has recently been shown to have the capacity to bind histone lysine acetylation. Here, we show that the YEATS domain of Taf14, a member of key transcriptional and chromatin-modifying complexes in yeast, is a selective reader of histone H3 Lys9 acetylation (H3K9ac). Structural analysis reveals that acetylated Lys9 is sandwiched in an aromatic cage formed by F62 and W81. Disruption of this binding in cells impairs gene transcription and the DNA damage response. Our findings establish a highly conserved acetyllysine reader function for the YEATS domain protein family and highlight the significance of this interaction for Taf14.