Updated project metadata. Project description: Taking advantage of a newly generated model system, we examined the influence of class I HDAC catalytic and non-catalytic function on the cellular proteome and acetylome. Therefore, we generated HAP1 cell lines either lacking individual class I HDACs or expressing catalytically inactive isoforms. Using these cell lines, we investigated whether deletion or inactivation of specific class I HDACs better mimics inhibitor treated cells using isobaric labeling (TMTpro).