Poster abstracts

Poster number 4 submitted by Pei Zhang

Identification of Replication-Dependent and Replication-Independent Linker Histone Complexes

Pei Zhang (Department of Biological Chemistry and Pharmacology, The Ohio State University), Owen E. Branson (Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University), Michael A. Freitas (Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University), Mark R. Parthun (Department of Biological Chemistry and Pharmacology, The Ohio State University)

Abstract:
There are 11 variants of linker histone H1 in mammalian cells. Beyond their shared abilities to stabilize and condense chromatin, the H1 variants have been found to have non-redundant functions, the mechanisms of which are not fully understood. Like core histones, there are both replication-dependent and replication-independent linker histone variants. To better understand linker histone dynamics and assembly, we used chromatography and mass spectrometry approaches to identify proteins that are associated with replication-dependent and replication-independent H1 variants. We identified proteins that bind to all histone variants and proteins that are specific for only one class of variant. The factors identified include histone chaperones, transcriptional regulators, RNA binding proteins and ribosomal proteins. Tpr, which was found to associate with only replication-dependent linker histones, specifically promoted their stability. These findings suggest that association with variant-specific binding partners may regulate linker histone dynamics.

Keywords: chromatin, linker histone, histone chaperone