SIN3Bcontaining

Sin3B-containing refers to a class of multi-subunit transcriptional corepressor complexes that include the Sin3B (SIN3B) protein as a central scaffold. In human cells, Sin3B serves as a core component of histone deacetylase (HDAC)–containing complexes that are related to the Sin3A-containing complexes but with distinct subunit compositions and target genes. The Sin3B complexes are primarily associated with HDAC1 and HDAC2 and participate in the removal of acetyl groups from histone tails to promote chromatin condensation and transcriptional repression.

Composition and organization of Sin3B-containing complexes can vary by organism and cellular context. Core components typically include the Sin3B scaffold, HDAC1/2, and additional subunits such as retinoblastoma-binding proteins (RBBP4/RBBP7) and other associated factors that help recruit the complex to specific genomic loci. The precise constellation of subunits can influence the gene targets and regulatory outcomes of the complex, and some components found in Sin3B complexes may differ from those in Sin3A complexes.

Functions and roles of Sin3B-containing complexes are centered on transcriptional repression through histone deacetylation. By partnering with sequence-specific transcription factors and other chromatin modifiers, these complexes are recruited to promoter and enhancer regions to regulate gene expression. They are involved in processes such as development, cell cycle control, differentiation, and responses to DNA damage, with activity that can vary by tissue and developmental stage.

Clinical relevance and research interest continue to grow, as misregulation of Sin3B-containing complexes can impact cellular homeostasis and may contribute to disease contexts, including cancer. Further studies aim to delineate tissue-specific targets, dynamic assembly, and therapeutic potential of modulating Sin3B-associated HDAC activity.