Characterization of O-GlcNAc cycling and proteomic identification of differentially O-GlcNAcylated proteins during G1/S transition

► S phase entry is correlated with a marked decrease of O-GlcNAc modified proteins ► O-GlcNAcase activity increases at the G1/S transition ► Identification of 58 differentially putative O-GlcNAcylated proteins during G1/S transition ► We report cell-cycle dependent O-GlcNAcylation of nucleoplasmic DNA licensing factors MCMs ► O-GlcNAcylation may regulate DNA replication initiation