SIN3 homolog A, transcription regulator (yeast); Acts as a transcriptional repressor. Interacts with MXI1 to repress MYC responsive genes and antagonize MYC oncogenic activities. Also interacts with MAD-MAX heterodimers by binding to MAD. The heterodimer then represses transcription by tethering SIN3A to DNA. Acts as a corepressor for REST (By similarity) (1273 aa)