DNA is wrapped around histone proteins, making up the fundamental unit of chromatin—the nucleosome. This organization is used to regulate diverse cellular functions and efficiently store the genetic code. The dynamic addition and removal of molecules on histones is catalyzed by various enzymes, including histone acetyltransferases—which add acetyl-CoA—and phosphatases—which remove phosphate groups. These post-translational modifications represent a mode of regulating cellular processes. The enzyme Gcn5 is a conserved H3/H2B histone acetyltransferase with multiple established roles and a proposed role in centromeric function. The protein phosphatase 2A (PP2A) has a conserved regulatory subunit, Rts1, which regulates diverse processes including cell size, septin dynamics during cell division, and chromosomal biorientation. Our lab recently described a genetic interaction between GCN5 and RTS1, whereby overexpression of RTS1 rescues gcn5 mutant phenotypes, and simultaneous loss of both genes is lethal. Due to reported connections of both Gcn5 and Rts1 to the centromere, we sought to determine whether the centromeric histone Cse4 is involved in the relationship between these two enzymes. We performed a screen of phosphorylatable and acetylatable Cse4 residues to determine whether any Cse4 residues are actively modified in the GCN5/RTS1 relationship. We identified three Cse4 residues that are critical for the suppression of gcn5∆ phenotypes by RTS1 overexpression. Mutating each of these identified residues to alanine interferes with rescue of gcn5Δ temperature sensitivity, DNA damage sensitivity, and cell cycle progression. Further studies will be conducted to determine how these Cse4 residues are used in the centromeric function of these conserved enzymes. Both Rts1 and Gcn5 regulate diverse processes and are frequently implicated in disorders including cancer and neurodegeneration, and understanding their role at the centromere will help elucidate their function in cellular regulation.