THE DERMATOMYOSITIS-SPECIFIC AUTOANTIGEN MI2 IS A COMPONENT OF A COMPLEX CONTAINING HISTONE DEACETYLASE AND NUCLEOSOME REMODELING ACTIVITIES

Histone acetylation and deacetylation were found to be catalyzed by st ructurally distinct, multisubunit complexes that mediate, respectively , activation and repression of transcription. ATP-dependent nucleosome remodeling, mediated by different multisubunit complexes, was thought to be involved only in transcription activation. Here we report the i solation of a protein complex that contains both histone deacetylation and ATP-dependent nucleosome remodeling activities. The complex conta ins the histone deacetylases HDAC1/2, histone-binding proteins, the de rmatomyositis-specific autoantigen Mi2 beta, a polypeptide related to the metastasis-associated protein 1, and a novel polypeptide of 32 kDa . Patients with dermatomyositis have a high rate of malignancy. The fi nding that Mi2 beta exists in a complex containing histone deacetylase and nucleosome remodeling activities suggests a role for chromatin re organization in cancer metastasis.