HISTONE DEACETYLASE AND THE RETINOBLASTOMA PROTEIN

The balance between cellular proliferation and differentiation is stri ctly controlled in the cell and the deregulation of this balance can l ead to tumour formation. The tumour suppressor protein Rb plays a key role in this balance essentially by repressing progression through the cell cycle and thereby it blocks the cell in GI phase. Rb represses S phase genes through the recruitment of an enzyme which modifier DNA s tructure, the histone deacetylase HDAC1. The Rb/HDAC1 complex ir a key element in the control of cell proliferation and differentiation. Mor eover this complex is likely to be a target for transforming viral pro teins.