Nuclear dynamics of the Set1C subunit Spp1 prepares meiotic recombination sites for break formation

Zsolt Karányi, László Halász, Laurent Acquaviva, Dávid Jónás, Szabolcs Hetey, Beáta Boros-Oláh, Feng Peng, Doris Chen, Franz Klein, Vincent Géli, Lóránt Székvölgyi
2018 Journal of Cell Biology  
Spp1 is the H3K4me3 reader subunit of the Set1 complex (COMPASS/Set1C) that contributes to the mechanism by which meiotic DNA break sites are mechanistically selected. We previously proposed a model in which Spp1 interacts with H3K4me3 and the chromosome axis protein Mer2 that leads to DSB formation. Here we show that spatial interactions of Spp1 and Mer2 occur independently of Set1C. Spp1 exhibits dynamic chromatin binding features during meiosis, with many de novo appearing and disappearing
more » ... nding sites. Spp1 chromatin binding dynamics depends on its PHD finger and Mer2-interacting domain and on modifiable histone residues (H3R2/K4). Remarkably, association of Spp1 with Mer2 axial sites reduces the effective turnover rate and diffusion coefficient of Spp1 upon chromatin binding, compared with other Set1C subunits. Our results indicate that "chromosomal turnover rate" is a major molecular determinant of Spp1 function in the framework of meiotic chromatin structure that prepares recombination initiation sites for break formation.
doi:10.1083/jcb.201712122 pmid:30037925 fatcat:soxan6v3tzc35n4dximt46337i