Profiling the chromatin-bound proteome (chromatome) in a simple, direct, and reliable manner might be key to uncovering the role of yet uncharacterized chromatin factors in physiology and disease. Here, we have designed an experimental strategy to survey the chromatome of proliferating cells by using the DNA-mediated chromatin pull-down (Dm-ChP) technology. Our approach provides a global view of cellular chromatome under normal physiological conditions and enables the identification of chromatin-bound proteins de novo. Integrating Dm-ChP with genomic and functional data, we have discovered an unexpected chromatin function for adenosylhomocysteinase, a major one-carbon pathway metabolic enzyme, in gene activation. Our study reveals a new regulatory axis between the metabolic state of pluripotent cells, ribosomal protein production, and cell division during the early phase of embryo development, in which the metabolic flux of methylation reactions is favored in a local milieu.

We acknowledge support from the Spanish Ministry of Economy, Industry and Competitiveness to the EMBL partnership, Centro de Excelencia Severo Ochoa, the CERCA Programme/Generalitat de Catalunya, the Secretary for Universities and Research of the Ministry of Economy and Knowledge of the Government of Catalonia (to S.A. and A.A.-C.). The CRG/UPF Proteomics Unit is a member of the ProteoRed PRB3 consortium that was supported by grant PT17/0019 of the PE I+D+i 2013–2016 from the Instituto de Salud Carlos III (ISCIII), ERDF, and “Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya” (2017SGR595). The Di Croce Laboratory was supported by grants from the Spanish Ministerio de Educación y Ciencia (BFU2016-75008-P), AGAUR, and La Marato TV3