Required for G1/S transition. Recruits and stabilizes the origin recognition complex (ORC) onto chromatin during G1 to establish pre-replication complex (preRC) and to heterochromatic sites in post-replicated cells. Binds a combination of DNA and histone methylation repressive marks on heterochromatin. Binds histone H3 and H4 trimethylation marks H3K9me3, H3K27me3 and H4K20me3 in a cooperative manner with DNA methylation. Required for silencing of major satellite repeats. May be important ORC2, ORC3 and ORC4 stability.
Subcellular locations: Nucleus, Chromosome, Centromere, Chromosome, Telomere, Cytoplasm, Cytoskeleton, Microtubule organizing center, Centrosome, Chromosome, Centromere, Kinetochore
Localizes to heterochromatin during G1 phase. Restricted to centromeres or telomeres as cells progress though S phase. When cells enter mitosis, relocalizes to centromeres. Recruitment to pericentric heterochromatin largely depends on the presence of H3K9me3.
Testis-specific. Drastically down-regulated in testis from patients with Sertoli cell-only syndrome (SCOS).