title: KAP1-independent transcriptional repression of SCAN-KRAB-containing zinc finger proteins.
abstract: The Krüppel-associated box-containing zinc finger gene family (KRAB-ZNF) is one of the largest gene families of transcriptional factors in the human genome. Although the functions of most of these genes remain to be determined, it is known that KRAB-mediated transcriptional repression requires a direct interaction with the KAP1 co-repressor. By mammalian one- or two-hybrid experiments in HEK293 cells, we compared transcriptional repression activities of 61 human KRAB-ZNFs. The results showed that six SCAN-KRAB-containing ZNFs are KAP1-independent transcriptional repressors whose SCAN-KRAB domain is unable to associate with KAP1 despite retaining transcriptional repression activity. Transcriptional repression activities of the SCAN-KRAB domain of KAP1-independent KRAB-ZNFs are not influenced by depletion of endogenous KAP1 levels by small interfering RNA. Although the mechanism by which KAP1-independent KRAB-ZNFs repress transcriptional activity remains to be elucidated, it appears that there may be a pathway for transcriptional repression that does not involve KAP1. These results provide new insight into the functions of the members of the KRAB-ZNF family.
authors.affiliation: Department of Human Genome Research, Kazusa DNA Research Institute, 2-6-7 Kazusa-Kamatari, Kisarazu, Chiba 292-0818, Japan.
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Itokawa
authors.forename: Toshihide
authors.initials: T
authors.lastname: Yanagawa
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamakawa
authors.forename: Naoko
authors.initials: N
authors.lastname: Watanabe
authors.forename: Hisashi
authors.initials: H
authors.lastname: Koga
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nagase
mesh_terms: D002460:Cell Line; D005786:Gene Expression Regulation; D006801:Humans; D051741:Kruppel-Like Transcription Factors / Q000235:genetics*; D012097:Repressor Proteins / Q000378:metabolism; D014158:Transcription, Genetic; D000076183:Tripartite Motif-Containing Protein 28; D016335:Zinc Fingers / Q000235:genetics*
chemical_list: D051741:Kruppel-Like Transcription Factors; D012097:Repressor Proteins; C101116:TRIM28 protein, human; D000076183:Tripartite Motif-Containing Protein 28