Component or associated component of some histone methyltransferase complexes may regulate transcription through recruitment of those complexes on gene promoters (PubMed:19131338, PubMed:23178126). Enhances ligand-dependent transcriptional activation by nuclear hormone receptors (PubMed:12215545, PubMed:18180299, PubMed:19131338). Plays an important role in neural progenitor cell proliferation and self-renewal through the regulation of specific genes involved brain development, including REST (PubMed:23178126). Also controls the expression of genes involved in somatic development and regulates, for instance, lymphoblast proliferation (PubMed:23178126). {ECO:0000269|PubMed:12215545, ECO:0000269|PubMed:18180299, ECO:0000269|PubMed:19131338, ECO:0000269|PubMed:23178126}. This is the function of ENSG00000198026 (ZNF335, zinc finger protein 335).