Component of the HUSH complex, a multiprotein complex that mediates epigenetic repression. The HUSH complex is recruited to genomic loci rich in H3K9me3 and is probably required to maintain transcriptional silencing by promoting recruitment of SETDB1, a histone methyltransferase that mediates further deposition of H3K9me3. In the HUSH complex, contributes to the maintenance of the complex at chromatin (PubMed:26022416). Acts as a transcriptional corepressor and regulates the cell cycle, probably via the HUSH complex (PubMed:15474462, PubMed:17963697). The HUSH complex is also involved in the silencing of unintegrated retroviral DNA: some part of the retroviral DNA formed immediately after infection remains unintegrated in the host genome and is transcriptionally repressed (PubMed:30487602). May be involved in epithelial differentiation by contributing to epidermal integrity and barrier formation (PubMed:12853457). Homodimer (PubMed:12853457). Component of the HUSH complex; at least composed of TASOR, PPHLN1 and MPHOSPH8 (PubMed:26022416). Interacts with SIN3A and HDAC1 (PubMed:17963697). May interact with PPL (PubMed:12853457). In undifferentiated keratinocytes expressed in speckle-type nuclear granules and at the nuclear membrane, but in the differentiated keratinocytes colocalized with periplakin at the cell periphery and at cell-cell junctions (PubMed:12853457). Localizes to chromatin (PubMed:26022416). Ubiquitous. Substrate of transglutaminase (in vitro). May be due to intron retention. May be due to intron retention.