Antagonizes telomeric silencing in yeast. May recruit SIR4 to non-telomeric sites or repression. Homotetramer. Interacts with SIR4 N-terminal domain. Interacts with a complex composed of SIN3 and RPD3. Identified in the Set3C complex with HOS2, HST1, SNT1, CPR1, HOS4/YIL112W and SET3. The LisH domain mediates tetramerization and interaction with SNT1. Present with 1620 molecules/cell in log phase SD medium.