BioProject

The NuA4 lysine acetyltransferase complex acetylates histone and non-histone proteins and functions in transcription regulation, cell cycle progression, and DNA repair. More...

The NuA4 lysine acetyltransferase complex acetylates histone and non-histone proteins and functions in transcription regulation, cell cycle progression, and DNA repair. NuA4 harbors an interesting duality in that its catalytic module can function independently and distinctly as picNuA4. At the molecular level, picNuA4 anchors to its bigger brother via physical interactions between the C-terminus of Epl1 and the HSA domain of Eaf1, the NuA4 central scaffolding subunit. This is reflected at the regulatory level, as picNuA4 can be liberated genetically from NuA4 by disrupting the Epl1-Eaf1 interaction. As such, removal of either Eaf1 or the Epl1 C-terminus offers a unique opportunity to elucidate the contributions of Eaf1 and Epl1 to NuA4 biology and in turn their roles in balancing picNuA4 and NuA4 activities. Using high-throughput genetic and gene expression profiling, and targeted functional assays to compare eaf1∆ and epl1-C∆ mutants, we found that EAF1 and EPL1 had both overlapping and distinct roles. Strikingly, loss of EAF1 or its HSA domain led to a significant decrease in the amount of picNuA4, while loss of the Epl1 C-terminus increased picNuA4 levels, suggesting starkly opposing effects on picNuA4 regulation. The eaf1∆ epl1-C∆ double mutants resembled the epl1-C∆ single mutants, indicating that Eaf1’s role in picNuA4 regulation depended on the Epl1 C-terminus. Key aspects of this regulation were evolutionary conserved, as truncating an Epl1 homolog in human cells increased the levels of other picNuA4 subunits. Our findings suggested a model in which distinct aspects of the Epl1-Eaf1 interaction regulated picNuA4 amount and activity. Overall design: Microarray expression profiling was performed in duplicate. Cultures were grown in a 24-well plate incubator/reader to mid-log phase, with spiked-in RNA controls to monitor global changes in mRNA levels. Since no global changes in mRNA levels were detected, expression values were normalized to total mRNA levels. Fold changes were determined by comparing mutant to wild type profiles, with differentially expressed genes having a p-value <0.01 and absolute fold change >1.7 . Please note that the protocol_details.txt contains all protocol description. Less...