Beyond Histone and Deacetylase: An Overview of Cytoplasmic Histone Deacetylases and Their Nonhistone Substrates

Acetylation of lysines is a prominent form of modification in mammalian proteins. Deacetylation of proteins is catalyzed by histone deacetylases, traditionally named after their role in histone deacetylation, transcriptional modulation, and epigenetic regulation. Despite the link between histone deacetylases and chromatin structure, some of the histone deacetylases reside in various compartments in the cytoplasm. Here, we review how these cytoplasmic histone deacetylases are regulated, the identification of nonhistone substrates, and the functional implications of their nondeacetylase enzymatic activities

Isolation of a site-specifically modified RNA from an unmodified transcript

Natural RNAs contain many base modifications that have specific biological functions. The ability to functionally dissect individual modifications is facilitated by the identification and cloning of enzymes responsible for these modifications, but is hindered by the difficulty of isolating site-specifically modified RNAs away from unmodified transcripts. Using the m1G37 and m1A58 methyl modifications of tRNA as two examples, we demonstrate that non-pairing base modifications protect RNAs against the DNA-directed RNase H cleavage. This provide a new approach to obtain homogeneous RNAs with site-specific base modifications that are suitable for biochemical and functional studies