H4 replication-dependent diacetylation and Hat1 promote S-phase chromatin assembly in vivo.
While specific posttranslational modification patterns within the H3 and H4 tail domains are associated with the S-phase, their actual functions in replication-dependent chromatin assembly have not yet been defined. Here we used incorporation of trace amounts of recombinant proteins into naturally synchronous macroplasmodia of Physarum polycephalum to examine the function of H3 and H4 tail domains in replication-coupled chromatin assembly. We found that the H3/H4 complex lacking the H4 tail domain was not efficiently recovered in nuclei, whereas depletion of the H3 tail domain did not impede nuclear import but chromatin assembly failed. Furthermore, our results revealed that the proper pattern of acetylation on the H4 tail domain is required for nuclear import and chromatin assembly. This is most likely due to binding of Hat1, as coimmunoprecipitation experiments showed Hat1 associated with predeposition histones in the cytoplasm and with replicating chromatin. These results suggest that the type B histone acetyltransferase assists in shuttling the H3/H4 complex from cytoplasm to the replication forks.
UMR-CNRS 6204, Dynamique de la chromatine et épigénétique, Faculté des sciences et des techniques, Université de Nantes, 44322 Nantes, France.
Aïda
A
Ejlassi-Lassallette
Eloïse
E
Mocquard
Marie-Claire
MC
Arnaud
Christophe
C
Thiriet
D000107:Acetylation; D021581:Active Transport, Cell Nucleus; D042002:Chromatin Assembly and Disassembly; D004261:DNA Replication; D051548:Histone Acetyltransferases / Q000378:metabolism*; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D016839:Physarum polycephalum / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*
D006657:Histones; D011993:Recombinant Fusion Proteins; D051548:Histone Acetyltransferases; C110880:histone acetyltransferase type B complex