Dbf4 recruitment by forkhead transcription factors defines an upstream rate-limiting step in determining origin firing timing

Di Fang (1) , Armelle Lengronne (2) , Di Shi (3) , Romain Forey (2) , Magdalena Skrzypczak (4) , Krzysztof Ginalski (4) , Changhui Yan (5) , Xiaoke Wang (1) , Qinhong Cao (1) , Philippe Pasero (2) , Huiqiang Lou (1)

1 State Key Laboratory of Agro-Biotechnology, Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Biological Sciences, China Agricultural University, Beijing 100193, China
2 IGH - Institut de génétique humaine
3 State Key Laboratory of Agro-Biotechnology, Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
4 Laboratory of Bioinformatics and Systems Biology, Centre of New Technologies, University of Warsaw, 02-089 Warsaw, Poland
5 NDSU - North Dakota State University

Initiation of eukaryotic chromosome replication follows a spatiotemporal program. The current model suggests that replication origins compete for a limited pool of initiation factors. However, it remains to be answered how these limiting factors are preferentially recruited to early origins. Here, we report that Dbf4 is enriched at early origins through its interaction with forkhead transcription factors Fkh1 and Fkh2. This interaction is mediated by the Dbf4 C terminus and was successfully reconstituted in vitro. An interaction-defective mutant,dbf4ΔC, phenocopiesfkhalleles in terms of origin firing. Remarkably, genome-wide replication profiles reveal that the direct fusion of the DNA-binding domain (DBD) of Fkh1 to Dbf4 restores the Fkh-dependent origin firing but interferes specifically with the pericentromeric origin activation. Furthermore, Dbf4 interacts directly with Sld3 and promotes the recruitment of downstream limiting factors. These data suggest that Fkh1 targets Dbf4 to a subset of noncentromeric origins to promote early replication in a manner that is reminiscent of the recruitment of Dbf4 to pericentromeric origins by Ctf19.

Mots clés: DNA replication timing; Dbf4; forkhead transcription factor; limiting factors

Domaines: Sciences du Vivant [q-bio]; Génétique

Di Fang, Armelle Lengronne, Di Shi, Romain Forey, Magdalena Skrzypczak, et al.. Dbf4 recruitment by forkhead transcription factors defines an upstream rate-limiting step in determining origin firing timing. Genes and Development, 2018, 31 (23-24), pp.2405 - 2415. ⟨10.1101/gad.306571.117⟩. ⟨hal-01718532⟩