ALFIN-LIKE proteins bind H3K4me3 and recruit SWR1 to repress responsive genes [ChIP-Seq]

In eukaryotes, the canonical histones deposited during S-Phase are often replaced by histone variants at discrete loci after replication. This function is facilitated by histone chaperones and chromatin remodeling complexes. The chromatin remodeler SWR1 incorporates H2A.Z into chromatin in exchange for its canonical counterpart H2A. Despite its importance, the mechanisms by which SWR1 is recruited to its target loci are not yet fully understood. Here, we show that ALFIN-LIKE (AL) proteins direct the SWR1 complex to H3K4me3 loci, facilitating the deposition of H2A.Z. Simultaneous mutation of the seven AL genes (al7m) leads to severe developmental effects and aberrant upregulation of responsive genes. This geneset exhibits high levels of H3K4me3, which is recognized by AL5. Furthermore, al7m shows a decrease in H2A.Z occupancy, particularly at AL5-bound loci. Our data suggests that AL5, through its interaction with SWR1, guides its activity towards inducible genes. Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) for FLAG, histone H3 and H2A.Z as well as histone modifications H3K4me3 in Arabidopsis