Sin3a is a transcriptional repressor and a homologue of the SIN3 repressor from yeast. Sin3a associates with the strong repressive isoform of Mxi1, a helix-loop-helix leucone zipper that associates with Max to antagonize Myc oncogenic activities []. Unlike Mxi1 and Myc, expression of Sin3a does not vary during development []. Sin3a is a component of several complexes, including the REST-CoREST repressor complex [], the PER complex which maintains circadian rhythm []and the Sin3 HDAC complex []. Sin3a also interacts with FOXK1 to regulate cell cycle progression []. Sin3a has three PAH domains by which it interacts with HCFC1, REST and SAP30 [, ].
