OGT is targeted to gene promoters by Tet1. Upstream of the TSS (around −39bp, near the area where the TFIID complex is recruited to DNA), OGT:Tet complex recruits the transcription repressor sin3A, as well as the histone deacetylases, HDAC1 and Sirt1. Downstream of the TSS (around +455bp), OGT:Tet1 are associated with the PRC2 complex. O-GlcNAcylation of the methyltransferase subunit of PRC2, EZH2, enhances its activity by stabilization of the protein. O-GlcNAcylation of RING1b (the catalytic subunit of the PRC1 complex) also increases its activity leading to H2BK119 ubiquitination. All of these PMTs crosstalk and converge to result in gene transcription repression.