Sin3: master scaffold and transcriptional corepressor.

Sin3 was isolated over two decades ago as a negative regulator of transcription in budding yeast. Subsequent research has established the protein as a master transcriptional scaffold and corepressor capable of transcriptional silencing via associated histone deacetylases (HDACs). The core Sin3-HDAC complex interacts with a wide variety of repressors and corepressors, providing flexibility and expanded specificity in modulating chromatin structure and transcription. As a result, the Sin3/HDAC complex is involved in an array of biological and cellular processes, including cell cycle progression, genomic stability, embryonic development, and homeostasis. Abnormal recruitment of this complex or alteration of its enzymatic activity has been implicated in neoplastic transformation.