A Possible Role for CAF1 in the Incorporation of H3.3 in Arabidopsis [RNA-Seq]

Eukaryotic organisms organize their genetic material in chromatin rather than unprotected DNA. Efficient chromatin assembly is essential for all DNA-templated processes, including replication, transcription, and DNA repair. Our research focused on two major histone H3 deposition complexes: Chromatin Assembly Factor (CAF1), which deposits canonical H3 on naked DNA immediately after replication during the S-phase in yeast and metazoans, and the Histone Regulator A (HIRA) complex, which is thought to incorporate the H3.3 variant in a transcription-dependent manner. By combining biochemical, genetic, genomic, and proteomic data, we surprisingly discovered that CAF1 incorporates the histone variant H3.3 into Arabidopsis chromatin. Moreover, CAF1's role inH3.3 deposition is particularly pronounced in the transcribed regions of the genome. Overall design: RNA-Seq profiling of wildtype Columbia-0 and hira-1 and fas2-4 mutants at 12 days after germination (12DAG) seedlings.