Recruiter that couples transcriptional factors to general transcription apparatus and thereby modulates transcription regulation and chromatin formation. Can both act as an activator or a repressor depending on the context (PubMed:10777215). Required for HUSH-mediated heterochromatin formation and gene silencing (By similarity). Mediates MBD1-dependent transcriptional repression, probably by recruiting complexes containing SETDB1. Stabilizes SETDB1, is required to stimulate histone methyltransferase activity of SETDB1 and facilitates the conversion of dimethylated to trimethylated H3 'Lys-9' (H3K9me3). The complex formed with MBD1 and SETDB1 represses transcription and couples DNA methylation and histone H3 'Lys-9' trimethylation (H3K9me3) (PubMed:14536086). Facilitates telomerase TERT and TERC gene expression by SP1 in cancer cells (By similarity). Interacts with MBD1; the interaction is enhanced when MBD1 is sumoylated (By similarity). Interacts with SETDB1; the interaction protects SETDB1 from proteasomal degradation and is required to stimulate histone methyltransferase activity and facilitate the conversion of dimethylated to trimethylated H3 'Lys-9' (PubMed:14536086). Interacts with SUMO ubiquitin-like proteins (SUMO1, SUNO2 and SUMO3), with a preference for SUMO2 and SUMO3. Interacts with SP1, ATF7 and ZHX1. Interacts with the general transcription machinery, including ERCC2, ERCC3, GTF2E1, GTF2E2 and POLR2A (By similarity). Ubiquitously expressed at all stages studied. Belongs to the MCAF family.