関連性Gene transcription in eukaryotes is controlled by a dynamic interaction between transcriptional activation and repression, both taking place in the context of chromatin. Therefore, chromatin remodeling is one of the critical steps in gene silencing. Chromatin remodeling factors drive mobilization of the nucleosome by both catalyzation of ATP hydrolysis as well as by histone deacetylation. The acetylation status of histones at specific DNA regulatory sequences depends on the recruitment of histone acetyltransferase or histone deacetylase (HDAC) activities usually as part of large multiprotein complexes of coactivators or corepressors, respectively. RbAp48 is a 425 amino acids WD-domain protein isolated as a RB1 (retinoblas toma binding protein). RbAp46 (also known as RBBP7-retinoblastoma-binding protein 7) has 89% amino acid identity with RbAp48. RbAp46 and RbAp48 are found in association with chromatin remodeling complexes Sin3A/HDAC and NURD (nucleosomal remodeling and deacetylation complex). Transcriptional repressors exert their effects by recruitment of the Sin3A/HDAC correpressor complex, which contains a module composed of Sin3A, HDAC1, HDAC2, RbAp46, RbAp48, SAP30, and others. In the NuRD complex, HDAC1, HDAC2, RbAp48, and RbAp46 associate with MTA2, MBD3, MAT1L1, MBD3L1, CHD3, and CHD4 to form the nucleosomal remodeling and deacetylation (NuRD) complex.
Knight AS et al. A Lin-9 complex is recruited by B-Myb to activate transcription of G2/M genes in undifferentiated embryonal carcinoma cells. Oncogene28:1737-47 (2009).
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