Comprehensive analysis of interacting proteins and genome-wide location studies of the Sas3-dependent NuA3 histone acetyltransferase complex
Highlights • We characterise Sas3p and Gcn5p active HAT complexes in WT and deleted TAP-strains. • We confirm that Pdp3p interacts with NuA3, histones and chromatin regulators. • Pdp3p MS-analysis reveals its phosphorylation, ubiquitination and methylation. • Sas3p can substitute Gcn5p in acetylation of histone H3K14 but not of H3K9. • Genome-wide profiling of Sas3p supports its involvement in transcriptional elongation.
Histone H3 Lysine 4 Mono-methylation does not Require Ubiquitination of Histone H2B
The yeast Set1-complex catalyzes histone H3 lysine 4 (H3K4) methylation. Using N-terminal Edman sequencing, we determined that 50% of H3K4 is methylated and consists of roughly equal amounts of mono, di and tri-methylated H3K4. We further show that loss of either Paf1 of the Paf1 elongation complex, or ubiquitination of histone H2B, has only a modest effect on bulk histone mono-methylation at H3K4. Despite the fact that Set1 recruitment decreases in paf1delta cells, loss of Paf1 results in an increase of H3K4 mono-methylation at the 5' coding region of active genes, suggesting a Paf1-independent targeting of Set1. In contrast to Paf1 inactivation, deleting RTF1 affects H3K4 mono-methylation…
HAT1 and HAT2 Proteins Are Components of a Yeast Nuclear Histone Acetyltransferase Enzyme Specific for Free Histone H4
We have analyzed the histone acetyltransferase enzymes obtained from a series of yeast hat1, hat2, and gcn5 single mutants and hat1,hat2 and hat1,gcn5 double mutants. Extracts prepared from both hat1 and hat2 mutant strains specifically lack the following two histone acetyltransferase activities: the well known cytoplasmic type B enzyme and a free histone H4-specific histone acetyltransferase located in the nucleus. The catalytic subunits of both cytoplasmic and nuclear enzymes have identical molecular masses (42 kDa), the same as that of HAT1. However, the cytoplasmic complex has a molecular mass (150 kDa) greater than that of the nuclear complex (110 kDa). The possible functions of HAT1 a…
Bromodomain factor 1 (Bdf1) protein interacts with histones
AbstractUsing a yeast two-hybrid assay we detected an interaction between the N-terminal region of histone H4 (amino acids 1–59) and a fragment of the bromodomain factor 1 protein (Bdf1p) (amino acids 304–571) that includes one of the two bromodomains of this protein. No interaction was observed using fragments of histone H4 sequence smaller than the first 59 amino acids. Recombinant Bdf1p (rBdf1p) demonstrates binding affinity for histones H4 and H3 but not H2A and H2B in vitro. Moreover, rBdf1p is able to bind histones H3 and H4 having different degrees of acetylation. Finally, we have not detected histone acetyltransferase activity associated with Bdf1p.
Structural Characterization of Set1 RNA Recognition Motifs and their Role in Histone H3 Lysine 4 Methylation
Departament de Bioquimica iBiologia Molecular, Universitatde Valencia, C/Dr Moliner 50,46100, Burjassot, SpainThe yeast Set1 histone H3 lysine 4 (H3K4) methyltransferase contains, inaddition to its catalytic SET domain, a conserved RNA recognition motif(RRM1). We present here the crystal structure and the secondary structureassignment in solution of the Set1 RRM1. Although RRM1 has the expectedβαββαβ RRM-fold, it lacks the typical RNA-binding features of thesemodules. RRM1 is not able to bind RNA by itself in vitro, but a constructcombining RRM1 with a newly identified downstream RRM2 specificallybinds RNA. Invivo,H3K4 methylation isnot affectedbyapoint mutation inRRM2 that preserves Set1 s…
Unveiling novel interactions of histone chaperone Asf1 linked to TREX-2 factors Sus1 and Thp1
13 páginas, 7 figuras, 2 yablas
Gcn5p is involved in the acetylation of histone H3 in nucleosomes.
Abstract Enzymatic extracts from a gcn5 mutant and wild-type strains of Saccharomyces cerevisiae were chromatographically fractionated and the histone acetyltransferase activities compared. When free histones were used as substrate, extracts from wild-type cells showed two peaks of activity on histone H3 but extracts from gcn5 mutant cells showed only one. With nucleosomes as substrate, the histone acetyltransferase activities present in extracts from the gcn5 mutant strain were not able to modify H3 whereas wild-type cell extracts acetylated intensely this histone. The activity that acetylated nucleosome-bound H3 behaved as a 170-kDa complex. We suggest that Gcn5p represents a catalytic su…
Tandem affinity purification of histones, coupled to mass spectrometry, identifies associated proteins and new sites of post-translational modification in Saccharomyces cerevisiae
Histones and their post-translational modifications contribute to regulating fundamental biological processes in all eukaryotic cells. We have applied a conventional tandem affinity purification strategy to histones H3 and H4 of the yeast Saccharomyces cerevisiae. Mass spectrometry analysis of the co-purified proteins revealed multiple associated proteins, including core histones, which indicates that tagged histones may be incorporated to the nucleosome particle. Among the many other co-isolated proteins there are histone chaperones, elements of chromatin remodeling, of nucleosome assembly/disassembly, and of histone modification complexes. The histone chaperone Rtt106p, two members of chr…
Data for the identification of proteins and post-translational modifications of proteins associated to histones H3 and H4 in S. cerevisiae, using tandem affinity purification coupled with mass spectrometry
Tandem affinity purification method (TAP) allows the efficient purification of native protein complexes which incorporate a target protein fused with the TAP tag. Purified multiprotein complexes can then be subjected to diverse types of proteomic analyses. Here we describe the data acquired after applying the TAP strategy on histones H3 and H4 coupled with mass spectrometry to identify associated proteins and protein post-translational modifications in the budding yeast, Saccharomyces cerevisiae. The mass spectrometry dataset described here consists of 14 files generated from four different analyses in a 5600 Triple TOF (Sciex) by information‐dependent acquisition (IDA) LC–MS/MS. The above …
Protein Interactions within the Set1 Complex and Their Roles in the Regulation of Histone 3 Lysine 4 Methylation
Set1 is the catalytic subunit and the central component of the evolutionarily conserved Set1 complex (Set1C) that methylates histone 3 lysine 4 (H3K4). Here we have determined protein/protein interactions within the complex and related the substructure to function. The loss of individual Set1C subunits differentially affects Set1 stability, complex integrity, global H3K4 methylation, and distribution of H3K4 methylation along active genes. The complex requires Set1, Swd1, and Swd3 for integrity, and Set1 amount is greatly reduced in the absence of the Swd1-Swd3 heterodimer. Bre2 and Sdc1 also form a heteromeric subunit, which requires the SET domain for interaction with the complex, and Sdc…
Hif1 Is a Component of Yeast Histone Acetyltransferase B, a Complex Mainly Localized in the Nucleus
Hat1 is the catalytic subunit of the only type B histone acetyltransferase known (HAT-B). The enzyme specifically acetylates lysine 12, and to a lesser extent lysine 5, of free, non-chromatin-bound histone H4. The complex is usually isolated with cytosolic fractions and is thought to be involved in chromatin assembly. The Saccharomyces cerevisiae HAT-B complex also contains Hat2, a protein stimulating Hat1 catalytic activity. We have now identified by two-hybrid experiments Hif1 as both a Hat1- and a histone H4-interacting protein. These interactions were dependent on HAT2, indicating a mediating role for Hat2. Biochemical fractionation and co-immunoprecipitation assays demonstrated that Hi…