RT Journal Article SR Electronic T1 DAXX adds a de novo H3.3K9me3 deposition pathway to the histone chaperone network JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.09.20.508668 DO 10.1101/2022.09.20.508668 A1 Massimo Carraro A1 Ivo A. Hendriks A1 Colin M. Hammond A1 Victor Solis A1 Moritz Völker-Albert A1 Jonas D. Elsborg A1 Melanie B. Weisser A1 Christos Spanos A1 Guillermo Montoya A1 Juri Rappsilber A1 Axel Imhof A1 Michael L. Nielsen A1 Anja Groth YR 2022 UL http://biorxiv.org/content/early/2022/09/20/2022.09.20.508668.abstract AB A multitude of histone chaperones are required to protect histones after their biosynthesis until DNA deposition. They cooperate through the formation of co-chaperone complexes, but the crosstalk between nucleosome assembly pathways remains enigmatic. Using explorative interactomics approaches, we characterize the organization of the histone H3–H4 chaperones network and define the interplay between histone chaperone systems. We identify and validate several novel histone dependent complexes and predict the structure of the ASF1 and SPT2 co-chaperone complex, expanding the role of ASF1 in histone dynamics. We show that DAXX acts separately from the rest of the network, recruiting heterochromatin factors and promoting lysine 9 tri-methylation of new histone H3.3 prior to deposition onto DNA. With its functionality, DAXX provides a molecular mechanism for de novo heterochromatin assembly. Collectively, our findings provide a new framework for understanding how cells orchestrate histone supply and comply with chromatin dynamics throughout the cell cycle.Competing Interest StatementThe authors have declared no competing interest.