Chromatin Structure and Histone Modification in Response to Metabolism

The large amounts of DNA in eukaryotic cells is packaged into the nucleus by condensation into increasingly higher levels of compaction into chromatin. The fundamental subunit of chromatin is the nucleosome which contains an octamer of core histones and 146 bases of DNA. Repeats of this structure connected by variable length linker DNA form a “beads on a string” primary level of chromatin structure. Each core histone contains a structured domain that organizes the nucleosome core structure and less structured amino terminal tails. Post translational modification of these tails determines the accessibility of the underlying DNA sequence and serves as an address for the function of the underlying DNA sequences. The cell’s transcription program responds to cellular metabolism to adjust to different growth conditions. In this talk I will discuss the discovery of a histone modifying complex, SESAME, which responds to glucose metabolism and alters transcription through modification of histones.